Description
Title of Invention
COMMUNICATION CONTROL APPARATUS, COMMUNICATION CONTROL
5 METHOD, TERMINAL APPARATUS, AND INFORMATION PROCESSING
APPARATUS
Technical Field
[OOOl]
10 The present disclosure relates to co~nmunication control apparatuses,
communication control methods, terminal apparatuses, and information processing
apparatuses.
Background Art
15 [0002]
A technique called "beamfornling" has in recent years been widely known,
which is used by a base station having a plurality of antenna elements to form a beam
aimed at a terminal apparatus using the plturality of antenna elements. For example,
Long Term Evolution (LTE) release 10 specifies that a base station is equipped with
20 eight antennas.
[0003]
According to beanlforming, a beam airned in a desired direction is forlned
by nlultiplying a signal of each antenna element by a weight coefficient. For
example, in LTE, a terminal apparatus selects a recommended set from sets of weight
25 coefficients (i.e., precoding matrices) contained in a code book, on the basis of
reception of a reference signal transmitted by a base station, and notifies the base
station of the secotnmended set. Alternatively, a base station calculates a set of
weight coefficients on the basis of reception of a reference signal transmitted by a
terminal apparatus.
30 [0004]
For example, Patent Literature 1 indicates that a terminal apparatns selects a
desired set fsom sets of weight coefficients contained in a code book, and feeds the
desired set back to a base station, so that a set of weigtlt coefficients can be flexibly
determined.
5 Citation List
Patent Literature
[0005]
Patent Literatwe 1: JP 2010-537595T
10 Summa~yo f Inventiorl
Technical Problem
[0006]
However, according to the backgsound art including the above technique
described in Patent Literature 1, an increase in the number of antenna elements
15 possessed by a base station may be acconlpanied by an increase in load involved in
beamforming. As an example, an increase in the number of antenna elements is
accompanied by an increase in the number of weight coefficients, which in turn
increases a process for calculating the set of weight coefficients.
[0007]
20 It could be envisaged that, in order to reduce the increase in the load, a cell
ID is assigned to an individual beam so that a conlmunication region co~~esponding
to the beam (i.e., a region covered by the beam) is handled as a virtual cell.
However, the number of resource allocation patterns for a cell-specific reference
signal (CRS) that is transmitted for each cell (i.e., patterns of allocation of resource
25 elements to a CRS in a resource block) is limited, and therefore, interference may
occur between CRSs. As an example, interference may occur between a CRS
transmitted usiug a beam and a CRS transmitted in an adjacent cell.
[OOOS]
With the above in mind, it is desirable to provide an arratlgelnent capable of
30 reducing an itlcrease in the interference while reducing load involved in
Solution to Problem
[0009]
According to the present disclosure, there is provided a conullunication
5 control apparatus including: an acquisition unit configured to acquire cell
identification information assigned to an individual three-din1ensiona1 beam formed
by a directional antenna capable of forming a three-dinlensional beam; and a control
unit configured to control trans~nission of a reference signal performed using the
individual three-dimensional beam, on the basis of the cell identification information.
10 The control unit controls the transmission so that the reference signal is transmitted
in a limited portion of available resource blocks.
[OO lo]
According to the present disclosure, there is provided a comnunication
control method including: acquiring cell identification information assigned to an
15 individual three-dimensional beam formed by a directional antenna capable of
forming a three-dimensional beam; and controlling, by a processor, transmission of a
reference signal performed using the individual three-dimensional beam, on the basis
of the cell identification information. The reference signal is transmitted in a
limited portion of available resource blocks.
20 [OOll]
According to the present disclosure, there is provided a tenninal apparatus
including: an acquisition unit configured to, when a base station configured to
control transmission of a reference signal performed using an individual threedimensional
beam formed by a directional antenna capable of forming a tlxee-
25 dimensional beam, on the basis of cell identification information assigned to the
individual three-dimnensional beam, trans~nits information for specifying a limited
portion of available resource blocks in which the reference signal is transmitted,
acquire the information; and a co~ntnunicationc ontrol unit configured to measure the
reference signal transmitted in the liniited portion of the available resource blocks.
30 [0012]
According to the present disclosure, there is provided a co~nmunication
control method including: when a base station configured to control transmission of a
reference sigual performed using an iudividual three-dimensional beam fornted by a
directio~laal ntenna capable of fo~minga thee-dimensional beam, on the basis of cell
identification information assigned to the individual three-dimensional beam,
5 tra~~s~niniftosr mation for specifying a limited portion of available resource blocks in
\~l1icl1th e reference signal is transmitted, acquiring the information; and measuring,
by a processor, the reference signal transmitted in the limited po~tiono f the available
resource blocks.
[0013]
10 Accordiug to the present disclosure, there is provided an information
processiug apparatus including: a memoly configured to store a program; and one or
more processors capable of executing the program. The program executes, when a
base station co~lfiguredto co~ltroltr ansn~issiono f a reference signal performed using
an individual three-dimensional beam formed by a directional antenna capable of
15 forming a three-dimensional beam, on the basis of cell identification infor~iiatiou
assigned to the iudividual three-dimensional beam, transmits information for
specifying a limited portion of available resource blocks in which the reference
signal is transmitted, acquiring the information, and measuring the referetlce signal
transmitted in the limited portion of the available resource blocks.
20
Advantageous Effects of Invention
[0014]
As described above, according to the present disclosure, an increase in the
interference can be reduced while load involved in beamforming can be reduced.
25 Note that the effects described above are not necessarily limited, and along with or
instead of the effects, any effect that is desired to be introduced in the present
specification or other effects that can be expected from the present specification may
be exhibited.
30
[00 151
Brief Description of Drawings
[FIG. 11 FIG. 1 is an illustrative diagram for describing a relationship between the
position of each antenna eletnent and the three-dimensional direction of a beam.
[FIG. 21 FIG. 2 is an illustrative diagram for describing an example of a technique of
using weight coefficients for beamforming.
5 [FIG 31 FIG. 3 is an illustrative diagram for describing an example of a cell formed
by a sector antenna.
[FIG. 41 FIG. 4 is an illustrative diagram for describing an exanlple of an
itnprove~nenitn gain by a beam.
[FIG, 51 FIG. 5 is an illustrative diagram for describing an example of a relationship
10 between the number of antenna elements and the peak of an antenna gain.
[FIG. 61 FIG. 6 is an illustrative diagram for describing a first exarnple of a resource
allocation pattern for a CRS.
[FIG. 71 FIG. 7 is an illustrative diagram for describing a second example of a
resonrce allocation pattern for a CRS.
15 [FIG. 81 FIG. 8 is an illustrative diagram for describing a cell in a case where a signal
is not transmitted using a three-dimensional beam.
[FIG. 91 FIG. 9 is an illustrative diagram for describing a cell in a case where a signal
is transmitted using a three-dimensional beam.
[FIG. 101 FIG. 10 is an illustrative diagram sho\ving an example of a schematic
20 configuration of a con~municatiotsl ystem according to an embodinlent of the present
disclosure.
[FIG. 111 FIG. 11 is an illustrative diagram for describing an exan~ple of a threedimensional
beam formed by a base station.
[FIG. 121 FIG. 12 is an illustrative diagram for describing an exanlple of transmission
25 and reception of a signal in a tl~ee-dimensionalb eam.
[FIG. 131 FIG. 13 is a block diagram showing an example of a configuration of a base
station according to an embodiment of the present disclosure.
[FIG. 141 FIG. 14 is an illustrative diagram for describing an example of radio flames
in which a CRS is transmitted using a tlxee-dimensiona1 beam.
30 [FIG. 151 FIG. 15 is at1 illustrative diagram for describing an example of a fsequency
band in which a CRS is transmitted using a tlvee-dimensional beam.
[FIG. 161 FIG. 16 is a block diagram showing an example of a configuration of a
temlinal apparatus according to an ernboditnent of the present disclosure.
[FIG. 171 FIG. 17 is a flowchart showing an example of a schematic flow of a first
communication control process in a base station according to an embodiment of the
5 present disclosure.
[FIG 181 FIG. 18 is a flowchart showing an example of a sche~naticf low of a second
communication control process in a base station according to an embodiment of the
present disclosure.
[FIG. 191 FIG. 19 is a flowchart sho\ving an example of a schematic flow ofa third
10 communication control process in a base station according to an embodiment of the
present disclosure.
[FIG. 201 FIG. 20 is a flowchart showing an example of a schematic flow of a fourth
commur~icationc ontrol process in a base station according to an embodiment of the
present disclosure.
15 [FIG. 211 FIG. 21 is a flowchart showing an example of a schematic flow of a fifth
communication control process in a base station accorditig to an enlbodiment of the
present disclosure.
[FIG. 221 FIG. 22 is a flowchart showing an example of a schematic flow of a sixth
communication control process in a base station according to an e~nbodiment of the
20 present disclosure.
[FIG. 231 FIG. 23 is a flowchart showing an example of a schematic flow of a
communication control process in a terminal apparatus according to an embodiment
of the present disclosure.
[FIG. 241 FIG. 24 is a block diagram illustrating a first example of a schematic
25 configuration of an eNB to which the technology according to the present disclosure
nlay be applied.
[FIG. 251 FIG. 25 is a block diagram illustrating a second example of a sche~natic
configusation of an eNB to which the technology according to the present disclosure
may be applied.
30 [FIG. 261 FIG. 26 is a block diagram illustrating an exatnple of a schematic
configuration of a smartphone to which the technology according to the present
disclosure may be applied.
[FIG. 271 FIG. 27 is a block diagratn illustrating an example of a scheniatic
configuration of a car navigation apparatus to which the teclmologp according to the
present disclosure may be applied.
5
Description of Embodiments
[00 161
Hereinafter, (a) preferred embodiment(s) of the present disclosure will be
described in detail with reference to the appended drawings. In this specification
10 and the drawings, eletnents that have substantially the same function and structure
are denoted with the same reference signs, and repeated explanation is omitted.
[0017]
Also, in the present specification and the accompanying drawings, elements
having substantially the same functional configuration may be distinguished fron~
15 each other by different alphabetical letters added to the same reference sign. For
example, a plurality of elements having substantially the same functional
configuration are distinguished fsom each other when necessary, like terminal
apparatuses 200A, 200B, and 200C. Note that when a plurality of elements having
substantially the satne functional configuration do not have to be particularly
20 distinguished from each other, these elements are indicated only by the same
reference sign. For example, when the terminal apparatuses 200A, 200B, and 200C
do not have to be particularly distinguished from each other, these terminal
apparatuses are simply referred to as terminal apparatuses 200.
[OOl 81
Note that description will be provided in the following order,
1. Introduction
2. Schematic Configuration Of Cotnmunication System
3. Configuration Of Base Station
4. Configuration Of Terminal Apparatus
5. Flow Of Process
6. Application Examples
6.1. Application Examples Regarding Base Station
6.2. Application Examples Regarding Ter~nillaAl pparatus
7. Conclusion
[0019]
5 <>
Firstly, trends relating to beamforming, discussio~~resl ating to beamfor~ning,
and problerns relating to beamforming will be describe3 wit11 reference to FIG. 1 to
FIG. 9.
[0020]
(Trends Relating To Bean~forming)
Given the recent widespread use of mobile data conlmunication terminals, it
is urgently necessary to address explosively increasing traffic. To this end, the
Third Generation Partnership Project (3GPP) is studying techniques of increasing
communication capacity, such as multi-user multiple-input and multiple-output (MU-
15 MIMO), coordinated multipoir~ttr a~ismissionlreception( CoMP), and the like.
[002l]
LTE release 10 specifies that a base station is equipped with eight antennas.
Therefore, the antennas can be used to achieve eight-layer multiple-input and
nlultiple-output (MIMO) in the case of single-user MIMO (SU-MIMO). Eight-
20 layer MIMO is a technique of spatially multiplexing eight separate streams. Also,
four-user two-layer MU-MIMO can be achieved.
roo221
Terminal apparatuses have only a small space for accommodating antennas,
and limited processing capability, and therefore, it is difficult to increase the number
25 of antennas in a terminal, apparatus. Meanwhile, recent advances in antenna
mounting technology have made it possible to provide about 100 ailtennas in a base
station.
[0023]
It is expected that a base station thus equipped with about 100 antennas will
30 have a narrower half-width (an angle at wvhich the antenna gain is -3 dB) of a bean1
formed by the antennas. In other words, it is expected that it will be possible to
fort11 a sharp beam. Moreover, the arrangenlent of antenna elements on a plane will
allow for fornlation of a beam aimed in a desired three-ditnensional direction. It
has been proposed that such a beam aimed in a three-ditnensional direction is used to
transmit a signal to a specific building located higher than a base station.
5 [0024]
Also, the increase in the nunber of antennas allows for an increase in the
number of MU-MIMO users. When the number of antennas of a terminal apparatus
is two, the number of spatially separated streams is two for each tenninal apparatus,
and therefore, it is more reasonable to increase the number of MU-MIMO users than
10 to increase the number of streams for each terminal apparatus. For the above
various reasons, beamfornling in downlink of LTE is expected to be advanced.
[0025]
As the number of antennas iacreases, a sharper beam can be fonned, and
more sectors can be formed, and therefore, the number of users n~ultiplexedp er base
15 station can be increased.
[0026]
(Technique For Calculating Weight Coefficients For 3D Beamfornling)
The weight coefficietlt of each antenna element for bearnforn~ing is
represented by a cotnplex nutnbec This will be specifically described with
20 reference to FIG. 1.
[0027]
FIG. 1 is an illustrative diagram for describing a relationship between the
position of each antenna element and the three-dimensional direction of a beam.
Referring to FIG. 1, shown are antenna elements ananged in a grid pattern. Also,
25 shown are two orthogonal axes x and y on a plane on which the antenna elements are
placed, and an axis z perpendicular to the plane. Here, the direction of a beam to be
formed is represented by, for exanxple, an angle phi (Greek letter) and at1 angle theta
(Greek letter). The angle phi (Greek letter) is an angle between the xy-plane
component of the beam direction and the z-axis. Also, the angle theta (Greek letter)
30 is an angle between the beam direction and the z-plane. In this case, for exanple,
the weight coeEcient Vm, n of an antenna element that is m-th in the x-axis
direction and n-th in the y-axis direction nlap be represented as follows.
[0028l
[Math. 11
5 [0029]
In the above formula, f is a frequency, and cis the speed of light. Also, j is
the imaginary unit of a complex numbe~ Also, d, is at1 interval between each
antenna element in the x-axis direction, and d, is an interval between each antenna
element in the y-axis direction. Note that the coordinates of an antenna element are
10 represented as follows.
[0030]
[Math. 21
[0031]
15 After a desired three-dimensional direction has been detennined, the weight
coefficient of each antenna element can be obtained on the basis of the direction and
the frequency f. Such weight coefficients are used as shown in, for example, FIG. 2.
[0032]
FIG. 2 is an illustrative diagram for describing an example of a technique of
20 using weight coefficients for beamforming. Referring to FIG. 2, a transmission
signal 73 corresponding to each antenna element 71 is complex-multiplied by the
weight coefficient 75 of the antenna element 71. Thereafter, the transmission signal
complex-multiplied by the weight coefficient 75 is transmitted From the antenna
element 71. For example, the complex niultiplication of the weight coeficietlt 75 is
25 perfornled on a digital signal.
[0033]
Altliough an exanlple of the teclinique of calculating weight coefficients has
been described, the weight coefficient calculation technique is not limited to this.
Various calculation techniques may be applicable.
[0034]
(Beanlfomling In LTE)
Beatnfor~ning in LTE is roughly &vided into schemes in which precoding
5 based on a codebook is used and schemes in which precoding not based on a
codebook is used. Also, the schemes in which precoding based on a codebook is
used include closed-loop techniques and open-loop techniques.
[0035]
(Formation Of Virtual Cell Using Three-Dimensional Beam)
10 Accordi~ig to general beamforming, an increase in the number of antenna
elements possessed by a base station may be accompanied by an increase in load
involved it1 beamforming. As an exanlple, an increase in the number of antenna
elements is accompanied by an increase in the number of weight coefficients, which
in turn increases a process for calculating the set of weight coefficients. In other
15 words, load increases in terms of a process performed by a ter~ninal apparatus or a
base station. As another example, an increase in the number of antenna elements is
acconlpanied by an increase in the size of a codebook, and therefore, it is necessaly
to allocate more radio resources for notification of a recommended set of weight
coefficients, resulting in an increase in overhead. In other words, load increases in
20 terms of radio resources.
[0036]
It could be envisaged that, in order to reduce the increase in the load, an
individual three-dimensional beam (i.e., a bean1 aitned in a three-dimensional
direction) is assigned a cell ID so that a comnlunication region corresponding to the
25 three-dimensional beam (i.e., a region covered by the beam) is handled as a virtual
cell. In this case, for example, it could be envisaged that a base station transmits a
CRS for an individual three-dimensional beam using the individual threedimensional
beam. Moreover, for example, it could be envisaged that a base station
transmits a synchronization signal, system information, or the like for the individual
30 three-diniensional beam using the individual three-dimensional beam. The
synchronization signal contains, for example, a primary synchronization signal (PSS)
and a secondary sy~~cl~ottizatisoignn al (SSS). Also, the syste~ni nforlnation
contains, for exanlple, a master infonnation block (MIB) and a system information
block (SIB).
[0037]
5 For example, a terminal apparatus, when entering a cotnnlunication region
(i.e., a virtual cell) corresponding to a thee-dimensional beam, is syticluonized using
a synclxonization signal transmitted using the thee-dimensional beam, and acquires
system information transmitted using the tlxee-dimensional beam. Thereafter, the
terminal apparatus measures a CRS transmitted using the three-dimensional beam,
10 atid if the measurement result satisfies a predetermined condition, sends a report on
the measurement to a base station. Thereafter, for example, the base station
performs handover of the terminal apparatus to the con~munication region (i.e., a
virtual cell).
[0038]
15 For example, a base station multiplies a do\vnlitlk signal to a terminal
apparatus belonging to a virtual cell corresponding to a three-dimei~sionabl eam by a
weight coeficietit, and transmits the downlink signal using the three-dimensional
beam. Note that a base station may multiply an uplink signal from the terminal
apparatus by a weight coefficient to perform an uplink beamforming process.
20 [0039]
(Size Of Cell Of Base Station)
The size of a service area of a base station (i.e., the size of a cell) in the
background art is calculated from transmission loss characteristics in a frequency
band used. Note that acceptable transmission loss is calculated from the necessary
25 reception power of a terminal apparatus, the transmission power of a base station, the
gain of a transsmission/reception antentla, and the like.
[0040]
A CRS transmitted by a base station in a do\vnlink iticludes a signal
sequence that is uniquely determined on the basis of a cell ID assigned to each base
30 station. A terminal apparatus measures the intensity of a received CRS that is
transmitted by a base station in a do\vnlink, and if, for example, the reception
intensity for a certain cell exceeds a predeternlined intensity, sends a report to the
base station. Tilereafter, the base station decides to perform haadover of the
terminal apparatus to the certain cell, for exanlple. In otlier words, the power of
transn~issiono f a CRS affects the size of a sel-vice area.
5 [0041]
(Non-Directional Area)
For example, a base station that is located at the center of a cell and
provides a sewice to the entire cell has a non-directional antenna. The nondirectional
antenna is an antenna that has no directivity on the horizontal plane and
10 radiates radio waves uniformly in all directions. The size of a service area formed
by a non-directional antenna is determined by the transmission power of a base
station and transmission loss.
[0042]
Also, for example, in an area where a large number of terminal apparatuses
15 are present, such as an urban area, a base station is located at a position where three
cells (also referred to as sectors) meet, instead of being located at the center of a cell.
As a result, a single base station can provide a service to three cells. In such a case,
the base station has a sector antenna for sadiating radio waves to the thee cells.
The sector antenna is implemented by providing a metal reflector on a back surface
20 of a dipole antenna. A specific example of a cell formed by a sector antenna will
now be described with reference to FIG. 3.
[0043]
FIG. 3 is an illustrative diagram for describing an example of a cell formed
by a sector antenna. Referring to FIG. 3, the beam width (-60 degrees to 60
25 degrees) of a sector antenna for fornling three cells (sectors) is shown. The beam
width is defined by a width at which the gain of an antenna is -3 dB. By aiming
such a beam in three directions, thee cells are fanned. The sizes of the thee
formed cells are determined by the transmission power of a base station and
transmission loss.
30 [0044]
Note that a service area corresponding to radio waves generated without
beamforming is herein referred to as a non-directional area. The radio waves may,
for example, be non-directional radio waves radiated by a non-directional antenna or
a sector beam radiated by a sector antenna. Alternatively, tie radio waves may be
radiated by a portion of a plurality of antenna elements possessed by a directional
6 antenna. Note that the non-directional area can be said to be a service area the size
of which is detern~inedf rom transmission power and transtnission loss.
[0045]
(Directional Asea)
A service area (communication region) col~espondingto a sharp beam, such
10 as a three-dimensional beam, is herein referred to as a directional area. The
intensity of radio waves in a non-directional area increases as one approaches the
center of a cell, and decreases as one approaches the periphery of a cell. Meanwhile,
the intensity of radio waves in a directional area is tnaintained relatively uniform.
[0046]
(Interference By Three-Dimensional Beam In Downlink)
It is expected that a three-dimensional beam is radiated toward a high
position (e.g., an upper position of a high-rise building). Therefore, for example, a
three-dimensional beam may also reach a high position in an adjacent cell (e.g., an
upper position of a high-rise building in an adjacent cell). Specifically, the three-
20 dimensional beam may reach a non-directional area of an adjacent cell or a
directional area of an adjacent cell. Therefore, a three-dimensional beam may cause
interference in an adjacent cell, leading to a decrease in the quality of comn~unication,
the capacity of con~municationo f a user, or the like.
[0047]
25 (Beam M'idth And Antenna Gain)
As a beam becomes sharper, the energy of radiated radio waves is more
concentrated, and therefore, the gain increases. This will now be described in
greater detail with reference to FIG. 4.
[0048]
30 FIG. 4 is an illustrative diagram for describing an example of an
improvement in gain by a beam. Referring to FIG. 4, a position 77 where an
antenna is provided is showvn. For example, when a non-directional antenna is
provided at the position 77, radio waves radiated by the non-directional antenna
reach a spherical region 78. Meanwhile, when a directional antenna capable of
forming a three-dimensional beam is provided at the position 77, radio waves having
5 a radiation angle theta (Greek letter) that are radiated by the directional antenna (i.e.,
a three-dimensional beam having the radiation angle theta that is formed by the
directional antenna) reach a region 79. Thus, as a beam becomes sharper, a region
that is reached by radio waves beconles narrower, so that the energy of the radio
waves is concentrated .into a nal-rowver region. As an example, when the antenna
10 gain of a non-directional antenna for radiating radio waves that can reach the
spherical region 78 is one, the antenna gain G of a directio~~aanl tenna for forming a
three-dimensional beam having the radiation angle theta is represented as followvs.
[0049]
[Math. 31
Note that as the number of antenna elements of a directional antenna
increases, the directional antenna can form a sharper beam. In other words, as the
number of antenna elements of a directional antenna increases, the peak of the gain
20 of the directional antenna is improved. A specific example of this ill now be
described with reference to FIG. 5.
[0051]
FIG 5 is an illustrative diagram for describing an exatnple of a relationship
between the nutnber of antemla elements and the peak of the antemla gain.
25 Referring to FIG. 5, a graph indicating the antenna gain with respect to the number of
antemla elements is shown~. Thus, as the number of antenna elements increases, the
peak of the antenna gain is improved.
[0052]
(Problems With Beamformi~ig)
As described above, in general beamfonning, an illcrease in the number of
antenna elenlents possessed by a base station may be acco~npaniedb y an increase in
load involved in beatnforming. For example, a process for calculating a set of
5 weight coefficients increases. In other words, load increases in terms of a process
performed by a terminal apparatus or a base station. Also, for example, it is
necessary to allocate more radio resources for tiotification of a recommended set of
weight coefficients, resulting in an increase in overhead. In other words, load
increases in terms of radio resources.
10 [0053]
Also, as described above, it could be envisaged that, in order to reduce the
increase in the load, an individual beam is assigned a cell ID so that a
communication region corresponding to the beam (LC., a region covered by the
beam) is handled as a virtual cell. In this case, for example, it could be envisaged
15 that a base station transmits a CRS for an individual three-diniet~sional beam using
the individual three-dimensiotial beam. Moreover, for example, it could be
envisaged that a base station transmits a synchronization signal (e.g., a PSS and a
SSS), system infor~nation (e.g., an MIB and an SIB), or the like for the individual
three-dimensional beam, using the individual three-dimensional beam.
20 LO0541
Interference Between CRSs
However, the number of resource allocation patterns for a CRS transmitted
for each cell (i.e., patterns of allocation of resource elements to a CRS in a resource
block) is -limited, and therefore, interference may occur between CRSs. As an
25 example, interference may occur between a CRS transmitted using a beam and a
CRS transmitted in an adjacent cell.
[0055]
More specifically, for example, 504 signal sequences (i.e., signal sequences
corresponding to 504 cell IDS) are prepared as signal sequences for a CRS.
30 Meanwhile, only six allocation patterns are prepared as a resource allocation pattern
for a CRS (i.e., a pattern of shift in the fieque~lcyd irection). It is easy to determine
cell IDS so that resource allocation patterns for a CRS do not overlap between base
stations and thereby avoid interference between CRSs. Howevel; when a large
number of beams are assigned different cell IDS, any of the beams and an adjacent
cell may have the same resource allocation pattern for a CRS. Therefore, there is
5 the possibility that interference occurs between CRSs. A speciiic exalnple of a
resource allocation pattern for a CRS will now be desc~ibedw ith reference to FIG 6
and FIG. 7.
[0056]
FIG. 6 is an illustrative diagram for describing a first example of a resource
10 allocation pattern for a CRS. Referring to FIG. 6, two resource blocks 83 arranged
side by side in the time direction in a sub-frame 81 are shown. Each resource block
83 has a width of one slot (i.e., seven OFDM symbols) in the time direction. Also,
each resource block 83 has a width 85 of 12 sub-carriers in the frequency direction.
A radio resource having a width of one OFDM in the time direction and a width of
15 one sub-carrier in the frequency direction is referred to as a resource element.
Some resource eletnents contained in each resource block 83 are allocated for a CRS,
and the CRS is transmitted using the allocated resource elements. Specifically, of
resource elements corresponding to the first OFDM symbol in each resource block,
two resource elements separated from each other by six sub-carriers are allocated for
20 a CRS. Also, of resource elements corresponding to the third OFDM symbol in the
resource block, two resource elements separated from each other by six sub-carriers
are allocated for a CRS. In this example, a CRS is transmitted using resource
elements 87A-87F.
[0057]
25 FIG. 7 is an illustrative diagram for describing a second example of a
resource allocation pattern for a CRS. Refel~ingto FIG. 7, two resource blocks 83
are shown as in FIG. 6. In this example, a CRS is transmitted using resource
elements 871-87P. In the example of FIG. 7, compared to the example of FIG. 6,
resource elements allocated for a CRS are shifted in the frequency direction by one
30 sub-carrier. Such a shift in the frequency direction has six shift patterns, and
therefore, there are six resource allocation patterns for a CRS.
[OOSS]
As deseribed above, resource allocation patterns for a CRS are limited, and
therefore, interference may occur between CRSs.
[0059]
5 Reduction hi Transmission Power For Non-Directional Area
Also, the transmission power of a base station should not exceed a
predetermined tnaximutn transmission powel; and therefore, if a signal (e.g., a CRS,
a synchronization signal, system information, ete.) is transmitted using an individual
three-dimensional beam in addition to trans~nission of a signal in a non-directional
10 area, the transmission power for the non-directional area may decrease. This may
lead to a reduction in user eomtnunieation capacity, a reduction in througllput, a
redaction in eell size, or the like.
[0060]
As an example, the transmission of a signal using a three-dimensional beam
15 causes a decrease in the power of transmission of a data signal in a downlink in a
non-directional area. As a result, the user communication capacity may decrease,
and the throughput may decrease.
[0061]
As ailother example, the translnission of a signal using a three-ditnensional
20 beam causes a decrease in the power of transmission of a CRS in a non-directional
area. Therefore, a region where the intensity of a received CRS exceeds a
psedeternlined reception intensity may decrease, and the non-directional area may
decrease. As a result, the user conlmunication capacity may decrease, and the
throughput may decrease. A specific example of this will be deseribed with
25 reference to FIG. 8 and FIG. 9.
[0062]
FIG. 8 is an illustrative diagram for describing a eell in a ease where a signal
is not transmitted using a three-dimensional beam. Referring to FIG. 8, a base
station 91A and a base station 91B that are adjacent to each other are shown. Also,
30 a eell 93A of the base station 91A and a eell 93B of the base station 9173 are shown.
The cell 93A and the eell 93B are a non-directional area. Moreover, terminal
apparatuses 95A-95C located in the cell 93A and terminal apparatuses 95D-95H
located in tlie cell 93B are showvn. The terminal apparatuses 95D-95H are located
in a high-rise building 97 located in the cell 93B. In this exarilple, the base station
91A does not transmit a signal using a tlxee-dimensional beam.
5 100631
FIG. 9 is an illustrative diagram for describing a cell in a case where a signal
is transmitted using a three-dimensional beam. Referring to FIG. 9, as in FIG. 8, a
base station 91A and a base station 91B, and terminal apparatuses 95A-95H, are
shown. In this example, the base station 91A transmits a signal (e.g., a CRS, a
10 synchronization signal, etc.) using a three-dimensional beam 99. Also, an increase
in transnlission power due to the transmission of the signal using the threedin~
ensional beam is accotnpanied by, for example, a decrease in the power of
transmission of a CRS in a non-directional area. Therefore, in the example of FIG.
9, conlpared to the exaniple of FIG. 8, the cell 93A which is a non-directional area is
15 small, and therefore, the terminal apparatus 95C is not located in the cell 93A and is
outside the cornmunication coverage. As a result, for example, the user
communication capacity decreases, and the throughput decreases.
[0064]
As described above, tlie transtnission power for a non-directional area may
20 decrease. Also, this nlay lead to, for example, a decrease in user communication
capacity, a decrease in throughput, a decrease in cell size, or the like.
[0065]
With the above in mind, embodiments of the present disclosure are provided
to reduce an increase in the interference while reducing load involved in
25 beamfor~ning, for example. Also, embodiments of the present disclosure are
provided to reduce a decrease in the transmission power for a non-directional area
while reducing load involved in beanlformiug, for example.
[0066]
>
30 Next, a schematic configuration of a comniunication system 1 according to
an embodinlent of the present disclosure will be described with reference to FIG. 10
to FIG. 12. FIG. 10 is an illustrative diagram showing all example of a schematic
configuration of the comn~~~nicatsioysnt em 1 according to an embodi~nento f the
present disclosure. Referring to FIG. 10, the con~municatio~syls tem 1 includes a
base station 100 and terminal apparatuses 200. The communication systeln 1
5 conlplies with, for example, LTE, LTE-Advanced, or other similar comnlnnication
scl~emes.
[0067]
The base station 100 performs radio communication wit11 terminal
apparatuses 200.
10 [0068]
Radio Communication In Nan-Directional Asea
The base station 100 performs radio communication with terminal
apparatuses 200 located in a cell 10. The cell 10 is a communication region (i.e., a
non-directional area) corresponding to radio waves generated without beamforming.
15 100691
For example, the base station 100 includes a non-directional antenna, and
transmits a signal using non-directional radio waves. The base station 100 transmits,
for example, a cell-specific reference signal (CRS) using non-directional radio waves.
Also, the base station 100 transmits, for example, other control signals (e.g., a
20 synchronization signal, systeln infornlation, etc.) and a data signal using nondirectional
radio waves.
[0070]
Note that the base station 100 may include a sector antenna instead of a nondirectional
antenna, and may transmit a signal using a sector bean generated without
25 beamforming, instead of a [on-directional beanl. Also, the base station 100 may
transmit a signal using radio waves generated without beamforming, by means of a
portion of a plurality of antenna elements possessed by a directional antenna, instead
of a tlon-directional antenna and a sector antenna.
[0071]
Radio Cornmunication In Directional Asea
Moreover, particularly in an embodinlent of the present disclosure, tlie base
station 100 i~~cludeas d irectional allteilna capable of forming a three-dimensional
beam (i.e., a beam aimed in a three-dimensional direction), and transmits a signal
using a thee-diniensiotial beam. A specific exanlple of this will now be described
with reference to FIG. 11.
5 lo0721
FIG. 11 is an illustrative diagram for describing an example of a theedimensional
beam formed by tlie base station 100. Referring to FIG. 11, a
directional antenna 101 is shown. The directional antenna 101 is capable of
forming a three-dimensional beam. As shown in FIG. 11, the directional antenna
10 101 forms a plurality of three-dimensional beatns 20 aimed in different thseedimensional
directions. For example, thus, the directional antemia 101 is provided
a high position, and the three-dimensional beams 20 are radiated in any direction
(downward, upward, or horizontal direction). The three-dimensional beams 20
reach respective corresponding communication regions 30. Specifically, a three-
15 dimensional beam 20A is formed, and the three-dinlensional beam 20A reaches a
communication region 30A. Also, a three-dimensional beam 20B is formed, and
the three-dimensional beam 20B reaches a com~nunication region 30B. Thus, the
three-dimensional beams 20 reach the communication regions 30. As a result,
terminal apparatuses 200 located in the cotmnunication regions 30 can receive
20 signals transmitted using the three-dimensional beams 20.
[0073]
Moreover, tlie base station 100 assignsa cell ID to an individual threedimensional
beam formed by the directional antenna, and transmits a CRS using the
individual thee-dimensional beam on the basis of the cell ID. In otller words, the
25 base station 100 handles a cottununication region (service area) corresponding to an
individual three-dimensional beam as a virtual cell.
[0074]
Specifically, for exan~plet,h e base station 100 assigns a cell ID to a thseedimensional
beam formed by a directional antenna, and trarismits a CRS for a signal
30 sequence corresponding to the cell ID in a resource allocation patten1 corresponding
to the cell ID. Also, for example, when the result of ~neasuremetiot f the CRS by a
terminal apparatus 200 satisfies a predeterlnined condition, the base station 100
performs handover of the terminal apparatus 200 to a communication region (service
area) corresponding to the individual three-dimensional beam. Thereafter, the base
station 100 transmits a signal toward the terminal apparatus 200 using the individual
5 three-dimensional bearn. Thus, a communication region (service area)
corresponding to an individual three-dimensional beam is handled as a virtual cell.
At1 example of radio comn~u~~icatiuosnin g a three-dimensional beam will be
described with reference to FIG. 12.
[0075]
10 FIG. 12 is an illustrative diagram for describing an exanlple of trarlsmission
and reception of a signal using a three-dimensional beam. Referring to FIG. 12, a
base station 100 and a terminal apparatus 200A and a terminal apparatus 200B are
shown. Moreover, shown are a three-dimensional beam 20A formed by the base
station 100 and a corresponding comtnunication region 30A, and a three-dimensional
15 beam 20B formed by the base station 100 and a corresponding communication
region 30B. The base station 100 assigns a first cell ID to the three-dimensional
beam 20A, and transmits a CRS for a signal sequence corresponding to the first cell
ID in a resource allocation pattern corresponding to the first cell ID. Thereafter, the
terminal apparatus 200A measures the CRS, and if the measurement result satisfies a
20 predetermined condition, sends a report on the measurement to the base station 100.
Thereafter, for example, the base station 100 performs handover of the terminal
apparatus 200A from the cell 10 to the comn~unication region 30A (virtual cell).
Thereafter, the base station 100 transmits a signal toward the terminal apparatus
200A using the three-dimensional beam 20A. Similarly, the base station 100
25 assigns a second cell ID to the three-dimensional beam 20B, and transmits a CRS for
a signal sequence corresponding to the second cell 1D in a resource allocation pattern
corresponding to the second cell ID. Thereaftel; the terminal apparatus 200B
measures the CRS, and if the measuremeut result satisfies a predetermined condition,
sends a report on the measurement to the base station 100. Thereaftel; for example,
30 the base station 100 performs handover of the terminal apparatus 200B fron~th e cell
10 to the co~nmunicationr egion 30B (virtual cell). Thereaftel; the base station 100
transmits a signal toward the terminal apparatus 2000 using the tluee-dimetisional
beam 20B.
[OD761
Note that the base station 100 can use the same radio resources (e.g., the
5 same resource block) to tratistnit a signal using the three-ditilensional beam 20A and
the three-dimensional beam 20B. This is because the three-dimensional beam 20A
does not substantially reach the communication region 30B which is reached by the
three-dimensional beam 20B, and the three-ditiiensional beam 20B does not
substantially reach the conimunication region 30A which is reached by the three-
10 dimensional beam 20A. Thus, users can be multiplexed using three-dimensional
beams.
100771
The power of transmission of a signal (e.g., a CRS, a synchronization signal,
etc.) transmitted using a three-dimensional beam may be set on the basis of the beam
15 width of the three-dimensional beam. For example, the antenna gain of a
directional antenna as used to form a three-dimensional beam is greater than the
antenna gain of a non-directional antenna (or a sector antenna). Therefore, as a
difference obtained by subtracting the antenna gain of a lion-directional antenna (or a
sector antentia) from the antenna gain of a directional antenna increases, the power of
20 transmission of a signal transmitted by a three-dimensional beam may be set to a
smaller value.
[0078]
Also, the beam width of a three-dimensional beam formed by a directional
antenna, and the direction of the three-dimensional beam, may be set on the basis of
25 user conditions (e.g., the location of a user, the number of users, etc.) or the like. In
other words, a set of weight coefficients for forming a three-dimensional beam may
be set on the basis of user conditions or the like. Also, a three-dimensional beam
formed by a directional antelma may be optionally added, or removed. In other
\\lords, an individual three-dimensional beam may be additionally formed by a
30 directional anteiula, or may not be subsequently formed.
LO0791
Synchronization In Frequency Direction And Time Direction
For example, radio connnunication in a non-directional area (i.e., the cell
10) and radio cor~l~~~unicaitni oan d irectional area (i.e., a conml~~nicatiorne gion
(virtual cell) corresponding to a three-dimensional beam) are kept synchronized in
5 the frequency direction and the time direction (frequency synctwonization and timing
synchronization). Also, for example, adjacent cells are kept s~~nclwonizeidn the
frequency direction and the time direction (fieqoency synchronization and timing
synchronization).
[OOSO]
10 In the foregoing, an example of the schematic configuration of the
communication system 1 according to an enlbodiment of the present disclosure has
been described. The communication system 1 according to an emboditnent of the
present disclosure can reduce an increase in the interference while reducing load
involved in beamforming. As a specific technique, the base station 100 transmits a
15 CRS using an individual three-dimensional beam on the basis of a cell ID assigned to
the individual three-dimensional beam. Also, the base station 100 transmits a CRS
using the individual three-dimensional beam in a limited portion of all available
resource blocks, instead of using all the resource blocks.
[0081]
<<3. Configuration Of Base Station>>
Next, an example of a configuration of the base station 100 accordi~~tog an
embodiment of the present disclosure will be described with reference to FIG. 13 to
FIG. 15. FIG. 13 is a block diapam showing an example of a configuration of the
base station 100 according to an embodinlent of the present disclosure. Referring to
25 FIG. 13, the base station 100 includes at1 antenna unit 110, a radio con~mu~iication
unit 120, a network communication unit 130, a storage unit 140, and a processing
unit 150.
[0082]
(Antenna Unit 110)
30 The antenna unit 110 radiates a signal output by the radio commu~ucation
unit 120, in the fonn of radio waves, into space. The antenna unit 110 also converts
radio waves in space into a signal, and outputs the signal to tlie radio comtnunication
n1ut 120.
[0083]
Radio Waves Generated Withotit Beamforming
5 The antenna unit 110 radiates radio waves generated without bearnforming.
For exainple, the antenna unit 110 includes a non-directional antenna, and transmits
non-directional radio waves. 111 other \vords, the antenna unit 110 radiates a signal
in the form of non-directional radio waves into space.
[OOX4]
10 Note that the antenna unit 110 may illclude a sector antenna instead of a
non-directional antenna, and may radiate, into space, a signal in the form of a sector
beam generated without beamfornling. Also, the antenna unit 110 may not include
a non-directional antenna or a sector antenna, and may include a directional antenna,
and may radiate, into space, a sigtial in tlie form of radio waves generated withont
15 beamfo~ming, using a portion of a plurality of antenna elements possessed by the
directional antenna, for example.
[OOSS]
Three-Dimensional Beam
In pal-ticular, in an embodiment of the present disclosure, the antenna unit
20 110 includes a directional antenna capable of forming a three-dimensional beam (i.e.,
a beam aimed in a three-dimensional direction), and forms a three-dimensional beam.
In other words, the antenna unit 110 radiates a signal in the form of a threedimensional
beam into space. For exainple, the antenna unit 110 forms a plurality
of three-dimensional beatns aimed in different thee-dimensional directions.
25 [OOXG]
The three-dimnetisional direction of a three-dimensional beam fortned by the
antenna unit 110 is determined on the basis of a set of weight coefficients
corresponding to tlie antenna elements. For example, the processing unit 150
(transmissioti control unit 155) tilultiplies a signal by a weight coefficient for each
30 antenna element. As a result, the antenna unit 110 forms a three-dimensional beam
aimed in a thee-diinensional direction that is determined on the basis of the weiglit
coefficients.
[0087]
(Radio Con~municationU nit 120)
The radio comnunication unit 120 performs radio communication. For
5 exanlple, the radio connnunication unit 120 transmits a downlink signal to a terminal
apparatus 200, and receives an uplink signal from a ternlinal apparatus 200.
[0088]
(Network Communication Unit 130)
The network communication unit 130 conmunicates with other
10 communication nodes. For example, the nettvork commu~lication unit 130
comnunicates with another base station 100 or a core network node.
[0089]
(Storage Unit 140)
The storage unit 140 stores a program and data for operation of the base
15 station 100.
[0090]
(Processing Unit 150)
The processing unit 150 provides val.ious functions of the base station 100.
The processing unit 150 includes a cell ID assignment unit 151, an information
20 acquisition unit 153, a transmission control unit 155, and a handover control unit 157.
[0091]
(Cell ID Assignment Unit 15 1)
The cell ID assignment unit 151 assigns cell identification information
(hereinafter referred to as a "cell ID") to an individual three-dimensional beam
25 formed by a directional antenna capable of fonning a three-dimensional beain.
[0092]
Specifically, for example, the cell ID assignment unit 151 assigns different
cell IDS to a plurality of individual three-dimensional beams formed by a directional
antemla. As a result, conltnul~ication regions respectively corresponding to the
30 plurality of three-dimensional beams can be handled as virtual cells. Note that the
cell IDS respectively assigned to the plurality of thee-dimensional beams are stored
in, for example, the storage unit 140.
[0093]
Resource Allocation Pattern Cor~espondingT o Cell ID
For example, the cell ID assigried to the individual three-dimensional beam
5 and a cell ID assigned to an adjacent cell have different resource allocation patterns
for a CRS. Specifically, the cell ID assignment unit 151 assigns, to the individual
three-dimensional beam, a cell ID corresponditlg to a resource allocation pattern that
is different fsom a resource allocation pattern corresponding to a cell ID assigned to
an adjacent cell. For example, the adjacent cell includes not only cells adjacent to
10 the cell 10, but also a small cell a portio~t or entirety of which is covered by the cell
10, and/or a small cell that is located in the vicinity of the cell 10.
[0094]
Specificall): for example, a cell ID corresponding to a resource allocation
pattern as shown in FIG. 6 is assigned to a cell adjacent to the cell 10. Meanwhile, a
15 cell ID corresponding to a resource allocation pattern as shown in FIG. 7 is not
assigned to any cell adjacent to the cell 10. In this case, the cell ID assignment unit
151 assigns any cell ID corresponding to a resource allocation patterti as shown in
FIG. 7 to a thee-dimensional beam.
[0095]
20 As a result, even when a three-dimensional beam that may be formed by the
base station 100 reaclies an adjacent cell, a CRS transmitted using the tllreedimensional
beam does not interfere wih a CRS in an adjacent cell (non-directional
area). For example, thus, an increase in interference between the CRSs can be
reduced.
25 [0096]
Note that the adjacent cell may be any of all adjacent cells that is located ill
the direction of the individual three-dimensional beam. In other words, the cell ID
assigried to the individual thee-dimensional beam may he assigned on the basis of
the direction of the individual three-dimensional beam. For example, a cell ID may
30 be assigned to the individual three-dimensional beam so that a resource allocation
pattern corresponding to a cell ID assigned to an adjacent cell located in the
directions of the i~idividual three-dimensional beam is different fro111 a resource
allocation pattern corresponding to the cell ID assigned to tlie i~ldividual threedin~
ensioliabl eani.
[0097]
5 Moreovel: the cell ID assigned to the i~idividual three-dimensional beam,
and a cell ID assigned to a three-dimensional beam formed by a base station of an
adjacent cell, may have different resource allocatiori patterns for a CRS. As a result,
even when a three-dimensional beani that may be formed by the base station 100
reaches an adjacent cell, a CRS transmitted using the three-dimensional beam does
10 not interfere with a CRS transmitted using a three-dimensional beam formed by a
base station of an adjacent cell. For example, thus, an increase in interference
between the CRSs can be further reduced.
[0098]
Technique Of Acquiring Cell ID
15 The cell ID assignment unit 151 acquires a cell ID assigned to at1 adjacent
cell from, for example, a core network node or the base station of the adjacent cell
tllrot~ghth e network communication unit 130.
[0099]
Note that the cell ID assignment unit 151 may acquire the cell ID of an
20 adjacent cell from a measurement report fiom a terminal apparatus 200. In
particular, the cell ID assig~inienut nit 151 may acquire the cell ID of an adjacent cell
from a measurement report from a terminal apparatus 209 beloiiging to a
communication region (virtual cell) corresponding to a thee-dimensional beam. As
a result, when the interference may pose a problem, a cell ID corresponding to a
25 resource allocation pattern that is different fiom a resource allocation pattern to
which a cell ID assigued to at1 adjacent cell corresponds, can be assigned to the
three-ditnensional beam as appropriate. For example, this is useful for a case where
s~iialcl ells are concetitrated in the direction of a three-dimensional beam.
[Ol 001
30 Alternatively, the base station 100 may include a dow~llinkre ceiver, and the
cell ID assignment unit 151 may acquire a cell ID assigned to an adjacent cell from a
signal (e.g., a synchronizatioti signal) transmitted by the adjacet~ct ell.
[OlOI]
The cell ID assignment unit 151 may acquire a cell ID assigned to a beam
formed by a base station of an adjacent cell using a technique similar to that which is
5 used for acquisition of a cell ID assigned to an adjacent cell.
[O 1 021
(Infortnation Acquisition Unit 153)
The information acquisition unit 153 acquires a cell ID assigned to an
individual three-dimensional beam that is formed by a directional antenna capable of
10 forming a three-dimensional beam.
[O 1031
For exatnple, as described above, the cell ID assigntilent unit 15 1 assigns
different cell IDS to a plurality of individual three-dimensional beams, respectively.
Thereafter, the information acquisition unit 153 acquires the cell IDS respectively
15 assigned to the plurality of three-dimensional beams. Thereafter, the infomlation
acquisition unit 153 provides the acquired cell IDS to the transmission control unit
155.
[0 1041
(Transmission Control Unit 155)
20 The transmission control unit 155 controls transmission of a signal
performed by the base station 100.
[0 1051
Transmission Of CRS Using Thee-Dimensional Beam
In particular, in an einbodiment of the present disclosure, the transmission
25 control unit 155 controls transniission of a CRS performed using an individual threedimensional
beam on the basis of a cell ID assigned to the individual threedimensional
beam.
[0 1061
Specifically, for example, in order to allow a CRS for a signal sequence
30 corresponding to a cell ID assigned to an individual thee-ditnensional beam to be
transmitted in a resource allocation pattern corresponding to the cell ID, the
transmission control unit 155 controls transmission of the CRS performed using the
individual thee-di~~~ensiobneaalm .
[0 1071
As an example, to achieve the control, the transmission control unit 155
5 inserts a CRS for a signal sequence corresponding to a cell ID assigned to an
individual three-dinlensional beam into resource elenlerits of a resource allocation
pattern corresponding to the cell ID. Thereafter, the transn~issionc o~ltrolu nit 155
multiplies the insested CRS by weight coefficients for the individual threedimensional
beam. As a result, the CRS for a signal sequence is transmitted using
10 the tl~ee-dinlensionalb eam in the resource allocation pattern.
[O 1081
Such transn~issiono f a CRS using a three-dimensional beam allows for, for
example, handling of a cotntnunication region corresponding to an individual threedimensional
beam as a virtual cell. Therefore, load involved in beamforming may
15 be reduced. For example, it is not necessary to calculate a recommended set of
weight coefficients for a three-dimensional beam for each terminal apparatus 200.
Therefore, even when the number of antenna elements increases, the process of
calculating a set of weight coefficients does not increase. In other words, load may
be reduced in terms of the process of the terminal apparatus 200 or the base station
20 100. Also, for example, it is not necessary to notify the base station 100 of a
recommended set of weight coefficients. Therefore, even when the number of
antenna elements increases, it is not necessary to use a large amount of radio
resources for notification of a recommended set of weight coefficients. In other
words, load may be reduced in terms of radio resources.
25 [0109]
Tra~lsmissionO f CRS Using Limited Portion of Resource Blocks
Moreover, in particular, in an embodiment of the present disclosure, the
transmission control unit 155 controls transn~ission of a CRS performed using an
individual tl~ee-din~ensionable am so that the CRS is transmitted using a limited
30 portion of available resource blocks. I11 other words, a CRS is tratlsmitted using a
three-dimensional beam in a limited portion of all available resource blocks, instead
of using all the available resource blocks.
[OIIO]
As a result, for example, an increase in the interference can be reduced.
Specificall>; for example, in the limited portion of resource blocks, interference may
5 occur between a CRS transmitted using a three-dimensional beam formed by the
base station 100 and a CRS transmitted in an adjacent cell. However, in resource
blocks other than the limited portion of resource blocks, the inte~ference does not
occur. Therefore, an increase in intesference betyeen the CRSs is reduced.
[Olll]
10 Therefore, according to an embodiment of the present disclosure, an
increase in the interference can be reduced while load involved in beamforming is
reduced.
[0112]
Also, for example, a decrease in transn~ission power for a non-directiot~al
15 area can be reduced. specific all^: for example, the number of resource blocks it1
. which a CRS is transmitted is limited, and therefore, the number of CRSs transmitted
using a thee-dimensional beam decreases, so that the power of transmission of CRSs
using a three-dimensional beam decreases. Therefore, a decrease in transmission
power for a non-directional area is reduced. As a result, a decrease in user
20 communication capacity, a decrease in throughput, and a decrease in cell size may
also be reduced.
[0113]
A more specific example of a limited portion of resource blocks will now be
described.
25 [0114]
- Trar~smissionO f CRS In Resource Blocks Within Limited Period Of Time
The limited portion of resource blocks is, for example, a resource block or
resource blocks within a limited period of time. Also, the limited period of time is,
for example, a limited poltion of radio fiames. In other words, a CRS is transmitted
30 using a three-ditnensional beam in a limited portion of radio frames. A specific
example of this will now be described with reference to FIG, 14.
[0115]
FIG. 14 is an illustrative diagram for describing an example of radio frames
in which a CRS is transmitted using a thee-dimensional beam. Referring to FIG.
14, radio frames with a system frame t~utnber( SFN) are shown. In this example, a
5 limited portion of radio frames is one of N radio frames. More specifically, the
limited portion of radio frames is radio frames with an SFN which is an integral
tnultiple of N (0, N, 2N, etc.). In other words, a CRS is transmitted using a thseedimensional
beam in radio frames with an SFN which is an integral tnultiple of N.
[0116]
10 As a result, for example, although, during the limited period of time (radio
frames), interference may occur between a CRS transmitted using a threedimensional
beam formed by the base station 100 and a CRS transmitted in an
adjacent cell, the interference does not occur during a period of time other than the
limited period of time. Therefore, an increase in interference between the CRSs is
15 limited to within the limited period of time.
[0117]
Also, for example, a period of time (radio frames) during which a CRS is
transmitted is limited, and therefore, allocation of pourer to transmission of a CRS
using a thee-dimensional beam is limited to within the limited period oftime (radio
20 frames). Therefore, a decrease in transtnission pourer for a non-directional area is
limited to within the limited period of time. As a resalt, a decrease in user
comn~unicationc apacity, a decrease in throughput, and a decrease in cell size may
also be limited to within the limited period of time.
[0118]
25 Moreover, for example, the limited portion of radio frames is radio frames
determined for each cell, and is different from a limited portion of radio fratnes
determined for an adjacent cell. In other words, radio frames in which the base
station 100 transmits a CRS using a three-dimensional beam are different from radio
fiames in which a base station of an adjacent cell transmits a CRS using a three-
30 dimensional beam.
[0119]
Referring back to the exatnple of FIG. 14, for example, tlie base station 100
transmits a CRS using a three-dimensional beam in radio frames with an SFN \vbich
is an integral multiple of N (0, N, 2N, etc.). Meanwhile, a base station of an
adjacent cell transnlits a CRS using a three-dimensional beam in radio frames with
5 an SFN which is an integral multiple of N plus one (I, N + 1,2N + 1, etc.).
[0120]
As a result, for example, interference betweell a CRS transmitted using a
three-dimensional beam formed by the base station 100 and a CRS transmitted using
a three-dimensional beam formed by a base station of an adjacent cell, can be
10 reduced.
[0121]
Note that, as described above, while a CRS may be transmitted it1 a limited
portion of radio frames in a directional area (i.e., a communication region or virtual
cell corresponding to a thee-dimensional beam), a CRS may be transmitted in all
15 radio frames in a non-directional area.
(0 1221
- Transmission Of CRS In Resource Blocks Within Limited Frequency Band
The limited portion of resource blocks is, for example, a resource block or
resource blocks within a limited portion of an available frequency band. In other
20 ~vords, a CRS is transmitted using a three-dimensional beam within a limited
frequency band. A specific exanlple of this will now be described with reference to
FIG. 15.
[0 1231
FIG. 15 is an illustrative diagram for describing an example of a frequency
25 band in which a CRS is transmitted using a three-dimensional beam. Referring to
FIG 15, radio resources that are a component carrier 41 and radio frames 43 are
shown. In this example, an available frequency band is the component carrier 41,
and a limited frequency band 45 is a band (e.g., a band of 1.4 MHz) including 72
central sub-carriers of the component carrier 41. 111 other words, a CRS is
30 transmitted in six central resource blocks of resource blocks arranged in the
frequency direction.
[0124]
As a result, for exanlple, although, within the limited frequency band,
interference inay occur between a CRS transmitted using a three-dimensional beam
formed by the base station 100 and a CRS transmitted in an adjacent cell, the
5 interference does not occur within a frequency band other than the limited frequency
band. Therefore, an increase in interference between the CRSs is limited to within
a limited frequency band.
[0 1251
Also, for .example, a frequency band in which a CRS is transmitted is
10 limited, and therefore, allocation of power to transmission of a CRS using a threedimensional
beam is limited to within the limited frequency band. Therefore, a
decrease in transmission power for a non-directional area per unit time (radio fran~e)
is reduced. As a result, a decrease in user communication capacity, a decrease in
throughput, and a decrease in cell size, per unit time (radio frame), may be reduced.
15 [0126]
Although, as described above, iu a directional area (i.e., a communication
region or virtual cell corresponding to a three-dimensional beam), a CRS is
transmitted in each resource block within a limited frequency band, a CRS may be
transmitted in each resource block within an available frequency band in a non-
20 directional area.
[0 1271
Transmission Of Information For Specifying Limited Portion Of Resource
Blocks
The transmission control unit 155 controls transmission of infonnation for
25 specifying a limited portion of resource blocks in which a CRS is transmitted.
[0128]
- Transmission Of First Time Information
As described above, for example, the limited portion of resource blocks i11
which a CRS is transmitted using a 'three-dimensional beam is a resource block or
30 resource blocks within a limited period of tinle. Also, the transmission control unit
155 controls transmission of information indicating the lin~ited period of time
(hereinafter referred to as "first time information"). hl other words, the first time
infornlation is transmitted.
[0129]
For example, the transmission control unit 155 controls transmission of
5 system inforn~atioici ontaining the first time information. Specifically, for example,
the transmission control unit 155 inserts a signal of the system information
containing the first time infor~nationi nto a resource element allocated for the system
information. As a result, the first time inforniation is transmitted as a portion of tlie
system information.
10 [0130]
Also, for example, the transmission control unit 155 controls transmission
of tlie first time information performed using radio waves generated without
beamforming. Specifically, for example, the transmission control unit 155 does not
multiply a signal of the system information containing the first time information by
15 weight coefficients for beatnforming. As a result, the system information
containing the first time inforn~ationi s transmitted in a non-directional area (the cell
10).
[0131]
Note that the first time information tnay be separately transmitted to a
20 terminal apparatus 200 by signaling instead of being transmitted as a portion of the
system information.
[0132]
As described above, the fist time information indicating a limited period of
time (radio frames) during which a CRS is transmitted is transmitted. As a result, a
25 terminal apparatus 200 can know a limited period of time (radio frames) during
\vhicli a CRS is transmitted using a three-dimensional beam. Therefore, a terniinal
apparatus 200 call measure a CRS transmitted during a linlited period of time (radio
frames). In other words, ~neasuremetlt is appropriately performed for a
comnunication region (i.e., a virtual cell) corresponding to a three-dimensional beam.
30 As a result, hatidover to a co~nmutlication region corresponding to a tlneeditnensiollal
bean1 can be appropriately performed. Also, for exaniple, tlie
co~~sumptioonf power of a terminal apparatus 200 for ~neasurenlentc an also be
reduced.
[0133]
- Transmission Of Bandwidth Information
5 As described above, for example, the limited portion of resource blocks in
which a CRS is transmitted using a three-dimensional bear11 is a resource block or
resource blocks within a limited poition of an available frequency band. Also, the
transn~ission control unit 155 controls transmission of a master information block
(MIB) performed using an individual three-dimensional beam. The MIB contains
10 information indicating the bandwidth of the limited frequency band (hereinafter
referred to as "first bandwidth information"). In other words, the first bandwidth
inforniation is transmitted as a portion of the MIB.
[0134]
Specifically, for example, the transmission control unit 155 inserts a signal
15 of the MIB containing the first bandwidth it~for~natioinnt o resource elements for the
MIB (i.e., resource eletnents of a physical broadcast channel (PBCB)). Thereafter,
the transmission control unit 155 multiplies the MIB signal by weight coefficients.
As a result, the first bandwidth information is transmitted as a portion of the MIB
using a three-dimensional beam.
20 [0135]
As a result, a terminal apparatus 200 located in a communication region
(virtual cell) corresponding to a three-dimensional beam can know the limited
frequency band in which a CRS is transmitted, from the bandwidth information
contained in the MIB. Therefore, a terminal apparatus 200 can measure a CRS
25 transmitted in the limited frequency band. As a result, handover to a
conlmunication region corresponding to a three-dimensional bam call be
appropriately performed.
[0136]
Moreover, for example, the transmission control unit 155 controls
30 transn~issiono f a system i~~fornlatibol~olc k (SIB) performed using an individual
three-dimensional beam. The SIB contains infannation indicating the available
frequency band (hereinafter referred to as "second bandwidth infor~nation"). In
other words, the second bandwidth inforlnation is transmitted as a portion of the SIB.
[0137]
Specifically, for example, the transmission cotitrol unit 155 inserts a signal
5 of the SIB containing the second bandwidth infor~nation into resource elements
allocated for the SIB (i.e., resource elements of a pllysical downlink shared channel
(PDSCH)). Thereaftel; the transmission control unit 155 multiplies the SIB signal
by weight coefficients. As a result, the second bandwidth information is
transmitted as a portion of the SIB using a tlwee-dimensional beatn.
10 LO1381
As a result, even when information about the bandwidth of a limited
frequency band is contained in an MIB, a terminal apparatus 200 located in a
comtnunication region (virtual cell) corresponding to a thee-dimensional beam can
know an actual available frequency band from bandwidth information contained in
15 an SIB. Therefore, the terminal apparatus 200 can perform radio communication
using allocated radio resources in an actual available frequency band.
[0139]
Note that an MIB contains the first bandwidth information indicating the
bandwidth of a limited fcequency band, but not the second bandwidth information
20 indicating the bandwidth of an available frequency band. Therefore, for examnple, a
legacy terminal apparatus performs radio comtnunication in a lin~itedfr equency band.
[0 1401
Transtnission Of Other Signals Within Limited Period Of Time
- Transmission Of Synchronization Signal Within Limited Period Of Time
25 For example, the transmission control unit 155 controls transti~ission of a
synchronization signal performed using an individual three-dimensional beam so that
the synchronization signal for the individual thee-dimensional beam is transmitted
within a limited period of time. Also, the limited period of time is, for example, a
limited portion of radio frames. In other words, the synchronization signal is
30 transmitted using a tlwee-dimensional beam in a lin~ited portion of radio frames.
For exan~plet,h e spnclxonization signal contains a PSS and an SSS, and the PSS and
the SSS contain a signal sequence corresponding to a cell ID assigned to a theedimensional
beam.
[0141]
As a result, for example, although interference may occur between a
5 synclchronization signal transmitted using a tlvee-din~ensional beam for~ned by the
base station 100 and a synchronization signal transmitted in an adjacent cell during
the limited period of time (radio frames), the interference does not occur during a
period of time other than the limited period of time. Therefore, an increase in
interference between the synchronization signals is limited to within a limited period
10 of tinle.
[0 1421
Also, for example, a period of time (radio frames) during which a
synchronization signal is transmitted is limited, and therefore, allocation of power to
transmission of a synchronization signal using a three-dirnensional beam is limited to
15 within a limited period of time (radio frames). Therefore, a decrease in
transmission power for a non-directional area is limited to within a limited period of
time. As a result, a decrease it1 user connnunication capacity, a decrease in
throughput, and a decrease in cell size may also be limited to within a limited period
of time.
20 [0143]
Although, as described above, in a directional area (i.e., a con~munication
region or virtual cell corresponding to a three-dimensional beam), a synchronization
signal is transmitted in a linlited portion of radio frames, a synchronization signal
may be transmitted in all radio frames in a non-directional area.
25 [0144]
- Transmission Of System Information Within Limited Period Of Time
For exan~ple, the transmissiot~ control unit 155 controls transmission of
systenl infonnation performed using an individual three-dimensional beatn so that
the system information for the individual three-dimensional bean1 is transmitted
30 within a limited period of time. Also, the limited period of time is, for exatnple, a
limited portion of radio frames. In other words, the system information is
transmitted using a tlxee-dimensional beam in a limited portion of radio frames.
The system irifor~nation contains, for example, an MIB and an SIB for a
con~lnunication region (virtual cell) corresponding to the individual threedimensional
beam.
5 [0145]
As a result, for example, although, during the limited period of time (radio
frames), interference may occur between system information transmitted using a
thee-dimensional beam fo111led by the base station 100 and system information
transmitted in an adjacent cell, the interference does not occur during a period of
10 time other than the limited period of time. Therefore, an increase in interference
between the pieces of system information is limited to within a Limited period of time.
[0146]
Also, for example, a period of time (radio fsames) during which system
information is transmitted is limited, and therefore, allocation of power to
15 transmission of system information using a three-dimensional bean1 is limited to
within a limited period of time (radio fsames). Therefore, a decrease in
transmission power for a non-directional area is limited to within a limited period of
time. As a result, a decrease in user communication capacity, a decrease in
tlxoughput, and a decrease in cell size may also be limited to within a limited period
20 oftime.
[O 1471
Although, as described above, in a directional area (i.e., a cornnnmication
region or virtual cell corresponding to a thee-dimensional beam), system
information is transmitted in a limited portion of radio fsames, system inforn~atioti
25 may be transmitted in the other radio fsames as well in a non-directional area.
[0148]
Also, a limited portion of radio fxarnes in which a CRS is transmitted using
a thee-dimensional beam, a limited portion of radio frames in ~vluch a
synchronization signal is transt~litted using a three-dimensional beam, and a limited
30 portion of radio fiames in which system information is transmitted using a threedimensional
beam, may all be the same or different from each other. As an example,
a limited portion of radio frames in wh'iclt a synchronization signal is transmitted
using a three-dimensional beam, and a limited portion of radio fsanles in which
system information is transmitted using a three-diniensional beam, may be a subset
of a lin~itedp ortion of radio franles in which a CRS is transmitted using a three-
5 dimensional beam.
[0 1491
Transmission Of Time Infornlation Indicating Limited Period Of Tirne
During Which Other Signals Are Transmitted
As described above, for exanlple, a synchronization signal for an individual
10 three-dimensional beam is transmitted during a limited period of time. Also, for
examnple, the transmission control unit 155 controls transmission of information
indicating the limited period of time during which a synchronizatioti signal is
transmitted (hereinafter referred to as "second time information"). For example, the
second time information is transmitted in a manner similar to that for the above first
15 time idonnation (i.e., information indicating a limited period of time during which a
CRS is transmitted). In other words, for example, the second time information is
transmitted as a portion of system information using radio waves generated without
beamforming.
[0150]
20 Also, as described above, for exaniple, system information for an individual
three-dimensional beam is transmitted during a limited period of time. For example,
the trans~nissionc ontrol unit 155 controls transmission of information indicating the
limited period of time during which system infor~nation is transmitted (hereinafter
referred to as "third time information"). For example, the third time information is
25 transmitted in a manner similar to that for the first time infor~nation( is., information
indicating a limited period of time during which a CRS is transmitted). Note that
the third time information contains, for example, information indicating a limited
period of time during which an MIB is transmitted, and information indicating a
limited period of time during which an SIB is transmitted.. In other words, for
30 example, the third time inforniation is transmitted as a portion of system infornlation
using radio waves generated without beamforming.
[0151]
Note that, in addition to each time information, a cell ID assigned to an
individual tluee-dimensional beam may also be transmitted as a portion of system
inforn~ationu sing radio waves generated without beamfornling. For example, the
5 cell ID may be transmitted as a portion of inforn~ationr elated to an adjacent cell.
Also, information indicating that the cell ID is assigned to a virtual cell (a
communication region co~~espondingto a three-dimensional beam) may be
transmitted along with the cell ID.
[0152]
(Handover Control Unit 157)
The handover control unit 157 performs bandover of a terminal apparatus
200.
[0153]
For example, when a terminal apparatus 200 measures a CRS, and if the
15 measurement result satisfies a predetermined condition, the terminal apparatus 200
sends a report on the measuremetlt to the base station 100. Thereafter, for example,
the handover control unit 157 decides to perform handover (handover decision) on
the basis of the report. Thereafter, the handover co~~trouln it 157 performs a
handover execution process.
20 [0154]
The handover includes handover of a terminal apparatus 200 from the cell
10 to an adjacent cell. In particular, in this embodiment, the handover includes, for
example, handover of a terminal apparatus 200 from the cell 10 to a virtual cell (a
communication region corresponding to a thee-dimensional beam). Also, the
25 handover includes, for exanlple, handover of a termi~lala pparatus 200 from a vi~tual
cell to the cell 10.
[0155]
<<4. Configuration Of Ter~ninaAl pparatus>>
Next, an example of a configuration of the tenninal apparatus 200 according
30 to an embodiment of the present disclosure will be described with reference to FIG.
16. FIG. 16 is a block diagram showing an example of a configuration of the
ter~ninal apparatus 200 according to an embodiment of thc present disclosure.
Referring to FIG. 16, the tem~inaal pparatus 200 includes an antenna unit 210, a radio
co~lununication unit 220, a storage unit 230, an input unit 240, a display unit 250,
and a processing unit 260.
5 101561
(Antenna Unit 2 10)
The antenna unit 210 radiates a signal output by the radio comnlunication
unit 220, in the form of radio waves, into space. The antenna unit 210 also converts
radio waves in space into a signal, and outputs the signal to the radio con~munication
10 unit 220.
[0157]
(Radio Communication Unit 220)
The radio communication unit 220 performs radio cor~~munication. For
example, the radio communication unit 220 receives a downlink signal from the base
15 station 100, and transmits an uplink signal to the base station 100.
[0158]
(Storage Unit 230)
The storage unit 230 stores a program and data for operation of the terminal
apparatus 200.
20 101591
(Input Unit 240)
The input unit 240 receives an input entered by the user of the terminal
apparatus 200. The input unit 240 provides the input result to the processing unit
260.
25 [0160]
(Display Unit 250)
The display nnit 250 displays a screen that is presented to the user of the
terminal apparatus 200. For example, the display unit 250 displays the screen by
the control of the processing nnit 260 (display control nnit 265).
30 [0161]
(Processing Unit 260)
The processing unit 260 provides various fi~nctionso f a terminal apparatus
200. The l>rocessiug unit 260 includes an infornlation acquisition unit 261, a
comniu~licafionc ontrol unit 263, and a display control unit 265.
[0162]
5 (Information Acquisition Unit 261)
Acquisition Of Infolmation For Specifying Limited Portion Of Resource
Blocks
When the base station 100 transmits information for specifying a limited
portion of available resource blocks in which a CRS is transmitted, the infornlation
10 acquisition unit 261 acquires the infannation.
[O 1631
- Acquisition Of First Time Information
As described above, for example, the limited portion of resource blocks is a
resource block or resource blocks within a limited period of time. The infornlation
15 for specifying the limited portion of resource blocks contains information indicating
the limited period of time (i.e., the first time information). The limited period of
time is, for example, a limited portion of radio fsanies.
[0 1641
Specifically, for example, system information containing the first time
20 infornlation is transmitted using radio waves generated without beamforlning, in the
cell 10. Thereafter, when a ternlinal apparatus 200 is located in the cell 10, the
information acquisition unit 261 acquires the first tinie information contained in the
system information.
[0165]
- Acqnisition Of Band Information
As described above, for example, the limited portion of resource blocks is a
resource block or resource blocks in a limited portion of an available frequency band.
The i~lfor~natiofno r specifying the linlited portion of resource blocks contains
information indicating the bandwidth of the limited fsequency band (i.e., the first
30 bandwidth information).
[0166]
Specifically, for example, the first bandwidth information is contained in a
master information block (MIB) transmitted using an individual three-dimensional
beam. 111 other words, an MIB containing the first bandwidth information is
transmitted using an individual three-dimensional beam. For exainple, when a
5 terminal apparatus 200 is located in a communication region (virtual cell)
corresponding to the individual three-dimensional beam, the information acquisition
unit 261 acquires the first bandwidth information contained in the MIB.
[0167]
Moreover, for example, ~41ena systeni information block (SIB) containing
10 information indicating the bandwidth of the available frequency band (i.e., the
second bandwidth information) is transmitted using the individual three-dimensional
beam, the infornlation acquisition unit 261 acquires the information (i.e., the second
bandwidth information) contained in the SIB. For example, when a terminal
apparatus 200 is located in a comnn~nication regiou (virtual cell) corresponding to
15 the individual three-dimensional beam, the information acquisition unit 261 acquires
the second bandwidth information contained in the SIB.
[0168]
Acquisition Of Informatiot~ Indicating ' Limited Period Of Time
Transmitted Using Other Signals
20 As described above, for example, a synchronization signal for an individual
three-dimensional beam is transmitted by the base station 100 during a limited period
of time. Also, for example, infornlation indicating the limited period of time during
\vliich the synchonization signal is transmitted (i.e., the second time information) is
also transmitted by the base station 100. Thereafter, the information acquisition
25 unit 261 acquires the information indicating the limited period of time (i.e., the
second time infor~nation).
[0169]
Also, as described above, for example, system information for an individual
thee-dimensional beam is transmitted by the base station 100 during a limited period
30 of time. Also, for example, information indicating the limited period of time during
which the system infortilation is transmitted (i.e., the third time information) is also
transn~ittedb y the base station 100. Thereafter, the infomiation acquisition unit 261
acquires the infom~ationin dicating the limited period of time (i.c., the third time
infos~mation). Note that the third time information contains, for example,
information indicating a limited period of time during which an MIB is transmitted,
5 and information indicating a limited period of time during which an SIB is
transmitted.
[0 1701
(Conlmunication Control Unit 263)
Measurement
10 The cotnnlunication control unit 263 measures a CRS transmitted in a
limited portion of available resource blocks.
[0171]
Specifically, for example, the conununication control unit 263 measures a
CRS transmitted in resource blocks within a limited portion of radio fiames indicated
15 by the first time information. Also, the conununication control unit 263 measures a
CRS transmitted in resource blocks within a bandwidth indicated by the first
bandwidth information. In other vvords, the con~munication control unit 263
measures a CRS transmitted in resource blocks within a bandwidth indicated by the
first bandwidth infornlation, in a limited portion of radio frames indicated by the first
20 time information.
[0 1721
The communication control unit 263 measures, for example, reference
signal received power (RSRP) andlor reference signal received quality (RSRQ), etc.
[0173]
25 For example, the conununication control unit 263 sends a report on the
measurement when the measurement result (e.g., RSRQ andlor RSRQ) satisfies a
predetermined condition. As an example, when RSRQ or RSRQ exceeds a
predeternlined theshold, the conununication control unit 263 sends a report on the
measurement to the base station 100.
30 [0174]
Synchronization
For example, the co~n~nunication control unit 263 perfom~s a
syncl~ronization process using a synchronization signal transmitted using an
individual three-dimensional beam during a linlited period of tinic. Specifically, for
example, the communication control unit 263 performs a synchronization process
5 using a synchronization signal transmitted using a three-dimensional beam in radio
. frames indicated by the second time information.
[0175]
Control Of Radio Colllmnnication In Virtual Cell (Directional Area)
For example, the communication control unit 263 controls radio
10 comtnunication performed by a terminal apparatus 200 so that radio resources
allocated in an available frequency band are used.
[0176]
Specifically, for example, the communication control unit 263 acquires
information indicating resource blocks allocated for a terminal apparatus 200, of
15 resource blocks (radio resources) within a bandwidth indicated by the second
bandwidth information. The information indicating radio resources is scheduling
information transmitted in a PDCCH. For example, the communication control unit
263 controls downlink radio communication by detecting a signal in downlink
resource blocks allocated for a terminal apparatus 200. Also, for example, the
20 communication contsol unit 263 controls uplink radio communication by inselting a
signal into uplink resource blocks allocated for a ternlinal apparatus 200.
[0177]
(Display Control Unit 265)
The display control unit 265 controls display of an output screen that is
25 performed by the display unit 250. For example, the display control unit 265
generates an output screen that is displayed by the display unit 250, and causes the
display unit 250 to display the output screen.
[0178]
<<5. Flow Of Process>>
30 Next, an example of a co~nmunication control process according to an
embodiment of the present disclosure ~vilbl e described with reference to FIGS. 17 to
FIG. 24.
[0 1791
(First Co~mnicationC ontrol Process In Base Station: Assignment Of Cell
ID)
5 FIG. 17 is a flowchart showing an example of a schematic flow of a first
communication control process in a base station according to an enibodinient of the
present disclosure. The first comnlunication control process is involved in
assignment of a cell TD to a tllree-dimensional beam.
[O 1801
10 I f a three-dimensional beam is newly formed by a directional antenna
(S401: Yes), the cell ID assignment unit 151 assigns a cell ID to the newly formed
three-dimensional beam (S403). Thereafter, the information acquisition unit 153
acquires the assigned cell ID (S40.5).
[0181]
15 Also, i f the formation of a three-dimensional beam by the directional
antenna is stopped (S407: Yes), the cell ID assignment unit 151 cancels the
assignment of a cell ID to a three-dimensional beam (i.e., a three-dimensional beam
not formed) (S409). Thereafter, control proceeds hack to step S401.
[0 1821
20 (Second Co~nniunicationC ontrol Process In Base Station: Transmission Of
Time Information)
FIG. 18 is a flowchart showing an example of a schematic flow of a second
comn~unicationc ontrol process in a base station according to an embodiment of the
present disclosure. The second communication control process is involved it1
25 transmission of time information.
[0183]
The inforn~ation acquisition unit 153 acquires system infornlation
containing time inforn~ationin dicating a limited portion of radio frames (S411).
For example, the system information contains the first time inforniation indicating
30 radio frames in which a CRS is transmitted using a three-dimensional beam, the
second time infonnation indicating radio frames in which a synchronization signal is
transmitted using a three-dimensional beam, and the third time infonnation
indicating radio frames in which system itifornlation is transmitted using a theedinlensional
beam.
[0184]
5 Thereaftel; the base station 100 tratlsrnits the system information using radio
\wives generated without beamfornling, under the control of the transmission control
unit 155 (S413). The radio waves may be non-directional radio waves radiated by a
non-directional antenna, or may be a sector beam radiated by a sector antenna.
Alternatively, the radio waves may be radio waves radiated by a portion of a plurality
10 of antenna elements possessed by a directiot~al antenna. Thereafter, control
proceeds back to step S411.
[0185]
(Third Comtnunication Control Process In Base Station: Transmission Of
Synchronization Signal Using Three-Dimensional Beam)
15 FIG. 19 is a flowchart showing an example of a schematic flow of a third
communication control process in a base station according to an etnboditnent of the
present disclosure. The third conununication control process is involved in
transmission of a synchronization signal usirig a three-dimensional beam.
[0186]
20 If a radio franle is of a limited portion of radio frames in which a
synchronization signal is transmitted using a three-dimensional beam (S421: Yes),
the base station 100 transmits a synchronization signal using a three-dimensional
beam in the radio frame under the control of the transmission control unit 155 (S423).
The synchronization signal contains a signal sequence corresponding to a cell ID
25 assigned to the three-dimensional bearn.
[0187]
Meanwhile, if a radio frame is not of a limited portion of radio frames in
which a synchronization signal is transtnitted using a three-dimensional beam (S421:
No), the base station 100 does not transmit a sy~~chronizatiosnig nal using a three-
30 dimensional beam in the radio frame (S425).
I01881
For example, such a process is repeated for each radio frame.
[0189]
(Fourth Con~niunicatioC~o~n trol Process In Base Station: Transmission Of
MIB Using Thee-Diinensional Beatn)
5 FIG. 20 is a flo\vcIiai-t showing an example of a schematic flow of a fourth
commu~iication coritrol process in a base station accotding to an embodiment of the
present disclosure. The fou~fll communication control process is involved in
trans~ilissiono f an MIB using a three-dimensional beam.
[0 1 901
10 If a radio frame is of a limited portion of radio frames in wliich an MIB is
transtilitted using a thee-dimensional beam (S441: Yes), the base station 100
transmits an MID using a three-dimensional beam in the radio frame under the
control of the tra~ismission control unit 155 (S443). The MIB contains the first
bandwidth information indicating the bandwidth of a limited frequency band in
15 \vhich a CRS is transmitted using a three-dimensional beam.
[0191]
Meanwhile, if a radio frame is not of a limited portion of radio frames in
which an MIB is trat~smitted using a three-dimensional beam (S441: No), the base
station 100 does not transmit an MIB using a thee-dimensional beam in the radio
20 fiame (S445).
[0192]
For example, such a process is repeated for each radio frame.
[0 1 931
(Fifth Communication Control Process In Base Station: Transmission Of
25 SIB Using Thee-Dimensional Beam)
FIG. 21 is a flowvchart showing an example of a schematic flow of a fifth
communication control process in a base station according to an enlbodiment of the
present ~ ~ S C ~ O S U KT~li.e fifth cornnlunication control process is involved in
tra~~smissoifo a~n~ S IB using a three-dimensioiial beam.
30 [0194]
If a radio fratne is of a limited portion of radio frames in \vhich an SIB is
transmitted using a tlxee-dini~e~isiol~baela m (S461: Yes), the base station 100
transnlits an SIB using a three-dimensional beam in the radio frame under the control
of the transtnission control unit 155 (S463). The SIB contains the second
bandwidth information indicating the bandwidth of an available fsequency band.
5 [0195]
Meanwhile, if a radio kame is not of a limited portion of radio kames in
which an SIB is transmitted using a three-dimensional beam (S461: No), the base
station 100 does not transmit an SIB using a three-din~ensional bean1 in the radio
frame (S465).
10 [0196]
For example, such a process is repeated for each radio frame.
[0 1971
(Sixth Communication Control Process In Base Station: Transmission Of
CRS Using Three-Dimensional Beam)
15 FIG. 22 is a flowchart showing an example of a schematic flow of a sixth
conimunication control process in a base station according to an embodiment of the
present disclosure. The sixth comn~unication control process is involved in
transmission of a CRS using a three-dimensional beam.
[0 1981
20 If a radio frame is of a limited portion of radio fiatnes in ~4iicha CRS is
transmitted using a three-dimensional bean1 (S481: Yes), the base station 100
transmits a CRS using a three-dimensional beam in resource blocks within a limited
fsequency band under the control of the transmission coritrol unit 155 (S483). The
CRS contains a signal sequence colresponding to a cell ID assigned to the thee-
25 dimensional beam. Also, the CRS is tra~ismitted in each resource block in a
resource allocation pattern corresponding to the cell ID.
101991
Mean\vIule, if a radio kan~eis not of a limited portion of radio fsames in
n~l~ical iC RS is transmitted using a three-dimensional beam (S481: No), the base
30 station 100 does not trai~smit a CRS using a tlxee-dimensional beam in the radio
kame (S485).
[0200]
For example, such a process is repeated for each radio frame.
[0201]
(Communication Control Process In Terminal Apparatus)
5 FIG. 23 is a flowchart showing an example of a schematic flow of a
cornrnunication control process in a terniinal apparatus according to an enlbodinient
of the present disclosure. The conlmunication control process is started in a
conllnunication region (vi~h~caell l) corresponding to a three-dimensional beam after
a termitial apparatus 200 has been synchronized using a synchronization signal
10 transmitted using the three-dimneusional beam. Note that, at the time of the start of
the communication control process, a terminal apparatus 200 has already acquired
each item of time information (the first time information, the second time
information, and the third time information).
[0202]
15 Initially, the information acquisition unit 261 acquires an MIB transmitted
using a three-dimensional beam in a limited portion of radio fiames indicated by the
third time information (S501). The MIB contains the first bandwidth information
indicating the bandwidth of a limited frequency band in which a CRS is transmitted
using a three-dimensional beam.
20 (02031
Also, the information acquisition unit 261 acquires an SIB transmitted using
a three-dimensional beam in a limited portion of radio frames indicated by the third
time information (S503). The SIB contains the second bandwidth information
indicating an available frequency band.
25 [0204]
The co~nmu~~icatcioontt~ro l unit 263 measures a CRS transmitted using a
three-dimensional heam in resource blocks within the limited flequency band, in the
limited portion of radio frames indicated by the first time infornlation (S505).
Thereafter, if the measuremnent result satisfies a predetermined condition (S507: Yes),
30 the con~lnutiication control unit 263 sends a report on the measurement to the base
statioti 100 (S509). Othelwise (S507: No), the communication control unit 263
does not send the report.
102051
Thereaftel; if the conitnul~ication control unit 263 ends the measurement of
a comtnunication region (virtual cell) corresponding to the thee-dimensional beam
5 (S5 11 : Yes), the process is ended. Otherwise (S511: No), control proceeds back to
step S505. Note that, as an exaniple, the communication control unit 263 ends the
measurement when the synclwonous state cannot be maintained in the
communication region (virtual cell) cor~espondingto the three-dimensional beam.
102061
10 Note that handover of a tenninal apparatus 200 to the cotnmunication region
(virtual cell) corresponding to the three-dimensional beam may be perfornied while
steps S505S5 11 are repeated.
102071
>
15 Technology according to the present disclosure is applicable to various
products. For example, a base station 100 may be realized as any type of evolved
Node B (eNB) such as a macro eNB, a small eNB. The small eNB may be an eNB
that covers a cell smaller than a macro cell, such as a pico eNB, a micro eNB, a home
(femto) eNB, or the like. Instead, the base station 100 may be realized as any other
20 types of base stations such as a NodeB and a base transceiver station (BTS). The
base station 100 may include a main body (that is also referred to as a base station
apparatus) configured to control radio commn~~nicatioann, d one or more remote radio
heads (RRH) disposed in a different place from tlie main body. Also, various types
of terminals described below may function as the base station 100 by temporarily or
25 semi-permanently executing the functionality of the base station.
LO2081
For example, a terminal apparatus 200 may be realized as a mobile terminal
such as a smartphone, a tablet personal computer (PC), a notebook PC, a portable
game terminal, a portable/dongle type mobile router, and a digital camera, or an in-
30 vehicle terminal such as a car navigation apparatus. The terminal apparatus 200
may also be realized as a terminal (that is also referred to as a machine type
corn~nunication (MTC) terlninal) that perfornls machine-to-machine (M2M)
cor~u~iunicatiot~F. urthermore, the terminal apparatus 200 may be a radio
cornniunication module (such as an integrated circuit mnodule including a single die)
mounted on each of the ter~ninals.
5 [0209]
<6.1. Application Examples Regarding Base Station>
(First Application Example)
FIG. 24 is a block diagram illustrating a first example of a schematic
configuration of an eNB to which the technology of the present disclosure may be
10 applied. An eNB 800 includes one or more antennas 810 and a base station
apparatus 820. Each antenna 810 and the base station apparatus 820 may be
connected to each other via an RF cable.
[02 lo]
Each of the antennas 810 includes a single or nlultiple antenna elements
15 (such as multiple antenna elements included in an MIMO antenna), and is used for
the base station apparatus 820 to transmit and receive radio signals. Particularlj~i n
the embodiment of the present disclosure, the at least one antenna 810 is a directional
antenna capable of forming a thee-dimensional beam. The eNB 800 may include
the multiple antennab 810, as illustrated in FIG. 24. For example, the multiple
20 antennas 810 may be conlpatible with multiple frequency bands used by the eNB 800.
Although FIG. 24 illustrates the example in which the eNB 800 includes the mnltiple
antennas 810, the eNB 800 may also include a single antenna 810.
[021 I]
The base station apparatus 820 includes a controller 821, a memory 822, a
25 network interface 823, and a radio con~municationin terface 825.
[0212]
The controller 821 may be, for example, a CPU or a DSP, and operates
various functions of a higher layer of the base station apparatus 820. For exainple,
the controller 821 generates a data packet from data in signals processed by the radio
30 con~mu~licatioint erface 825, and transfers the generated packet via the network
interface 823. The controller 821 may bundle data from multiple base band
proccssors to gcnerate the bundled packet, and transfer the generated bundled packet.
The controller 821 may have logical functions of perfornting control such as radio
resource control, radio bearer control, mobility management, ad~tiissionc ontrol, and
scheduling. The control may be performed in corporation with an eNB or a core
5 network node in the vicinity. The memory 822 includes RAM and ROM, and stores
a program that is executed by the cot~troller 821, and various types of control data
(such as a terminal list, transmission power data, and scheduling data).
[02 131
The network interface 823 is a comrnunication interface for connecting the
10 base station apparatus 820 to a core network 824. The controller 821 may
communicate with a core itetwork node or another eNB via the network interface 823.
In that case, the eNB 800, and the core network node or the other eNB may be
connected to each other through a logical interface (such as an S1 interface and an
X2 interface). The network interface 823 may also be a wired communication
15 interface or a radio cornnlunication interface for radio backl~aul. If the iletwork
interface 823 is a radio com~nunicationin terface, the network interface 823 may use
a higher frequency band for radio cormn~~tiicatitohta~n a frequency band used by the
radio co~tlnlunicationin terface 825.
[02 141
20 The radio communication interface 825 supports any cellular
communication scheme such as Long Term Evolution (LTE) and LTE-Advanced, and
provides radio connection to a terminal positioned in a cell of the eNB 800 via the
antenna 810. The radio communication interface 825 may typically include, for
example, a baseband (BB) processor 826 and an RF circuit 827. The BB processor
25 826 niay perform, for example, encodingldecoding, modulating/demodulating, and
rn~~ltiplexinglde~~~~~ltiapnlde xpinergfo, rms various types of signal processing of
layers (such as L1, medium access control (MAC), radio link control (RLC), and a
packet data convergence protocol (PDCP)). The BB processor 826 may have a part
or all of tlte above-described logical fimctions instead of the controller 821. The
30 BB processor 826 may be a memory that stores a communication coritrol program, or
a module that includes a processor and a related circuit configured to execute the
program. Updating the program may allow the functions of thc BB processor 826
to be changed. The module inay be a card or a blade that is inserted into a slot of
the base station apparatus 820. Alternatively, the n~odulem ay also be a chip that is
mounted on the card or the blade. Meanwhile, the RF circuit 827 rnay include, for
5 example, a mixer, a filtel; and an amplifier, and transmits and receives radio signals
via the antelma 810.
[02 151
The radio co~n~nunicatioinn terface 825 may include the multiple BB
processors 826, as illustrated in FIG. 24. For example, the multiple BB processors
10 826 may be conlpatible with ~nultiple frequency bands used by the eNB 800. The
radio comn~unication interface 825 may include the multiple RF circuits 827, as
illustrated in FIG. 24. For example, the multiple RF circuits 827 may be compatible
with ~nultiplea ntenna elements. Although FIG. 24 illustrates the example in which
the radio communication interface 825 includes the multiple BB processors 826 and
15 the multiple RF circuits 827, the radio communication interface 825 may also include
a single BB processor 826 or a single RF circuit 827.
[02 161
(Second Application Example)
FIG. 25 is a block diagram illustrating a second example of a schematic
20 configuration of an eNB to which the technology of the present disclosure may be
applied. An eNB 830 i~lcludeso ne or more antennas 840, a base station apparatus
850, and an RRH 860. Each antenna 840 and the RRH 860 may be connected to
each other via an RF cable. The base station apparatus 850 and the RRH 860 may
be connected to each other via a high speed line such as an optical fiber cable.
25 [0217]
Each of the antelmas 840 includes a single or ~nultiple antenna elenlents
(such as lllultiple ante~ulae lements included in an MIMO antenna), and is used for
the RRH 860 to transmit and receive radio signals. Particularly in the embodiment
ofthe present disclosure, the at least one antenna 810 is a directional antenna capable
30 of fornling a tlxee-dimensional beam. The eNB 830 nlay include the lnultiple
antennas 840, as illustrated in FIG. 25. For exanlple, the ~nultiplea ntennas 840 may
be conlpatible with nlultiple frequency bands used by the eNB 830. Altl~oughF IG.
25 illustrates the example in which the eNB 830 includes the n~ultiplea ntennas 840,
the eNB 830 may also include a single antenna 840.
[02 1 81
5 The base station apparatus 850 includes a controller 851, a memory 852, a
network interface 853, a radio conmunication interface 855, and a connection
iuterface 857. The controller 851, the nlemory 852, and the network interface 853
are the same as the controller 821, the rnelnory 822, and the network interface 823
described with reference to FIG. 24.
10 [0219]
The radio co~ntnut~icatiot~in terface 855 supports any cellular
communication scheme such as LTE and LTE-Advanced, and provides radio
communication to a terminal positioned in a sector co~~espondintog the RRH 860
via the RRH 860 and the antenna 840. The radio comtnunication interface 855 may
15 typically include, for example, a BB processor 856. The BB processor 856 is the
same as the BB processor 826 described with reference to FIG. 24, except the BE
processor 856 is connected to the RF circuit 864 of the RRH 860 via the connection
interface 857. The radio communication interface 855 may include the multiple BB
processors 856, as illustrated in FIG. 25. For example, the multiple BB processors
20 856 may be compatible with multiple frequency bands used by the eNB 830.
Although FIG. 25 illustrates the example in which the radio conirnunication interface
855 includes the multiple BB processors 856, the radio comnunication interface 855
may also include a single BB processor 856.
[0220]
25 The connection interface 857 is an interface for connecting the base station
apparatus 850 (radio conlmunication interface 855) to the RRH 860. The
connection interface 857 may also be a conununication module for con~rnu~~icainti o~~
the above-described high speed line that connects the base station apparatus 850
(radio cornn~unicatiorin~t erface 855) to the RRH 860.
30 [0221]
The RRH 860 includes a connection interface 861 and a radio
com~~lunicatioinnt erface 863.
[0222]
The co~lncctioni nterfacc 861 is an interface for connecting the RRH 860
(radio communication interface 863) to the base station apparatus 850. The
5 connection intcrface 861 mayalso be a cotnmunication module for connnunication in
the above-described high speed line.
[0223]
The radio communication intcrface 863 transmits and receives radio signals
via the antcnna 840. The radio conn~lunicationin tcrface 863 may typically include,
10 for example, the RF circuit 864. The RF circuit 864 may include, for example, a
mixer, a filter, and an amplifier, and transmits and receives radio sigtlals via the
antenna 840. The radio connnunication interface 863 may include multiple F@
circuits 864, as illustrated in FIG. 25. For cxanlplc, the m~dtiplcR F circuits 864
map support multiple antenna elements. Although FIG. 25 illustrates the example
15 in \vlich the radio communication interfacc 863 includes the multiple RF circuits
864, the radio communication intcrface 863 may also includc a single RF circuit 864.
[0224]
In the eNB 800 and the cNB 830 shown in FIG. 24 and FIG. 25, the cell ID
assignment unit 15 1, the information acquisition unit 153, the transmission control
20 unit 155, atid the handover control unit 157 that are described with refcret~ccto FIG.
13 may be provided in the radio communication interface 825 and the radio
connnunication intcrface 855 and/or the radio communicatiot~ interface 863. Also,
at least a portion of these functions may be achieved by the controller 821 and the
controller 851.
25 [0225]
G6.2. Application Examples Regarding Terminal Apparatus>
(First Application Exanlplc)
FIG. 26 is a block diagram illustsating an example of a schematic
corifiguration of a smastphone 900 to which the technology of the present disclosure
30 inay be applied. The smartpllolle 900 includes a processor 901, a tnemoly 902, a
storage 903, an external connection interfacc 904, a camera 906, a sensor 907, a
microphone 908, an input device 909, a display device 910, a speaker 911, a radio
communication interface 912, one or more antenna switches 915, one or more
antennas 916, a bus 917, a battery 918, and an auxiliary controller 919.
102261
5 The processor 901 may be, for example, a CPU or a system on a chip (SoC),
and controls fi~nctionso f an application layer and another layer of the smartphone
900. The metnory 902 includes RAM and ROM, and stores a progranl that is
executed by the processor 901, and data. The storage 903 may it~clude a storage
medium such as a semiconductor memory and a hard disk. The external connection
10 interface 904 is an interface for connecting an external device such as a memory card
and a universal serial bus (USB) device to the smartphone 900.
[0227]
The camera 906 includes an image sensor such as a charge coupled device
(CCD) and a cornplen~entalym etal oxide semiconductor (CMOS), and generates a
15 captured image. The sensor 907 may include a group of sensors suc11 as a
nleasurement sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor.
The microphone 908 converts sounds that are input to the smartphone 900 to audio
signals. The input device 909 includes, for example, a touch sensor configured to
detect touch onto a screen of the display device 910, a keypad, a keyboard, a button,
20 or a switch, and receives an operation or an information input from a user. The
display device 910 includes a screen such as a liquid crystal display (LCD) and an
organic light-emitting diode (OLED) display, and displays an output image of the
smartphone 900. The speaker 911 converts audio signals that are output from the
smal?phone 900 to sounds.
25 [0228]
The radio communication interface 912 supports any cellular
communication scheme sucll as LTE and LTE-Advanced, and performs radio
conmlunication. The radio communicatio~iln terface 912 may typically include, for
example, a BB processor 913 aud an RF circuit 914. The BB processor 913 may
30 perfor~n, for example, encoding/decoding, modulatingldemodulating, and
tnultiplexing/demuItiplexing, and perfor~ns various types of signal processing for
radio co~lununication. Meanwhile, the RF circuit 914 may i~lclude,f or exa~nplea,
mixel; a filtel; and at1 amplifier, and transmits a~ld receives radio signals via the
antemla 916. The radio comnlunication interface 912 may also be a one chip
lllodule that has the BB processor 913 and the RF circuit 914 integrated thereon.
5 The radio commlulication interface 912 tnay include the multiple BB processors 913
and the nlultiple RF circuits 914, as illustrated in FIG. 26. Although FIG. 26
illustrates the example ill which the radio com~nunicationi nterface 912 i~~cludtehse
multiple BB processors 913 and the multiple RF circuits 914, the radio
communication interface 912 may also itlclude a single BB processor 913 or a single
10 RF circuit 914.
[0229]
Furtiernlore, in addition to a cellular communication scheme, the radio
cotnmunication interface 912 may suppoit another type of radio communication
scheme such as a short-distance radio com~nunication scheme, a near field
15 communication scheme, and a radio local area network (LAN) scheme. In that case,
the radio communicatiotl interface 912 may include the BB processor 913 and the RF
circuit 914 for each radio com~nunications cheme.
[0230]
Each of the antemla switches 915 switches connection destinatiotls of the
20 antennas 916 atnong multiple circuits (such as circuits for different radio
communication schemes) it~cludedin the radio communication interface 912.
1023 11
Each of the antennas 916 includes a single or multiple antenna elements
(such as nlultiple antenna elements included in an MIMO antelma), and is used for
25 the radio cotnmunication interface 912 to transmit and receive radio signals. The
stnartphone 900 may include the multiple antennas 916, as illustrated in FIG. 26.
Although FIG. 26 illustrates the exanlple in which the smartphone 900 includes the
multiple antennas 916, the smartphone 900 may also include a single antenna 916.
[0232]
30 Furthermore, the smartpho~le 900 may include the antenna 916 for each
radio corm~lunication scheme. In that case, the antenna switches 915 nlay be
omitted fro111 the configuration of tl~esm artphone 900.
102331
The bus 917 co~u~ectthse processor 901, the memory 902, the storage 903,
the external connection interface 904, the camera 906, the sensor 907, the
5 microphone 908, the input device 909, the display device 910, the speaker 911, the
radio commullication interface 912, and the auxiliary controller 919 to each other.
The battery 91 8 supplies power to blocks of the smartphone 900 illustrated in FIG. 26
via feeder lines, which are partially sl~own as dashed lines in tlle figure. The
auxiliary controller 919 operates a minimum necessary function of the smal-tpl~one
10 900, for example, in a sleep mode.
102341
In the sn~artphone9 00 shown in FIG. 26, the iufor~natioua cquisition unit
261 and the communication control unit 263 that are described with reference to FIG.
16 may be provided in the radio communication interface 912. Also, at least a
16 portion of these fi~nctionsm ay be achieved by the processor 901 or the auxiliary
controller 919.
[023 51
(Second Application Example)
FIG. 27 is a block diagram illustrating an exanlple of a schematic
20 configuration of a car navigatiol~ apparatus 920 to which the technology of the
present disclosure may be applied. The car navigation apparatus 920 includes a
processor 921, a memoly 922, a global positionit~g system (GPS) nodule 924, a
sensor 925, a data interface 926, a content player 927, a storage medium interface
928, an input device 929, a display device 930, a speaker 931, a radio
25 coinmunication interface 933, oue or more antentla switches 936, one or more
antent~as9 37, and a battery 938.
LO2361
The processor 921 may be, for example, a CPU or a SoC, and controls a
navigation fiinction and another function of the car navigation apparahls 920. The
30 memoly 922 includes RAM and ROM, and stores a program that is executed by the
processor 921, and data.
[0237]
The GPS module 924 uses GPS signals received from a GPS satellite to
measure a position (such as latitude, longitude, and altitude) of the car navigation
apparatus 920. The sensor 925 nlay iriclude a group of sensors such as a gyro
5 sensor, a geomagnetic sensor, and an air pressure sensor. The data interface 926 is
coln~ectedto , for example, an in-vehicle network 941 via a terminal that is not shown,
and acquires data generated by the vehicle, such as vehicle speed data.
[023 81
The content player 927 reproduces content stored in a storage medium (such
10 as a CD and a DVD) that is inserted into the storage medium interface 928. The
input device 929 includes, for example, a touch sensor configured to detect touch
onto a screen of the display device 930, a button, or a switch, and receives an
operation or an information input from a user. The display device 930 includes a
screen such as a LCD or an OLED display, and displays an image of the navigation
15 function or content that is reproduced. The speaker 931 outputs sounds of the
navigation hnction or the content that is reproduced.
LO2391
The radio communication interface 933 supports any cellular
communication scheme such as LET and LTE-Advanced, and performs radio
20 communication. The radio comnlunicatiot~in terface 933 may typically include, for
example, a BB processor 934 and an RF circuit 935. The BB processor 934 may
perform, for example, encoding/decoding, modulating/demodulating, and
multiplexing/den~ultiplexitig, and performs various types of signal processing for
radio comn1111iication. Meanwhile, the RF circuit 935 may iticlode, for example, a
25 mixel; a filter, and an amplifier, and transmits and receives radio signals via the
atitentia 937. The radio comlnunication interface 933 may be a otle chip module
having the BB processor 934 and the RF circuit 935 integrated thereon. The radio
communication interface 933 niay include the multiple BB processors 934 and the
nlultiple RF circuits 935, as illustrated in FIG. 27. Although FIG. 27 illustrates the
30 example in which the radio communication interface 933 includes the rnultiple BB
processors 934 and the n~ultiple RF circuits 935, the radio communication interface
933 may also include a single BB processor 934 or a single RF circuit 935.
[0240]
Furthernlore, in addition to a cellular cormnunication schetnc, the radio
conlmut~ication interface 933 may support another type of radio communication
5 scheme such as a short-distance radio con~munication scheme, a near field
co~unmnication schenie, and a radio LAN scheme. In that case, the radio
communication interface 933 may include the BB processor 934 and the RF circuit
935 for each radio commut~ications cheme.
[0241]
10 Each of the antenna switches 936 switches connection destinations of the
antennas 937 among ~nultiple circuits (such as circuits for different radio
co~nnlunications chemes) included in the radio conununication interface 933.
[0242]
Each of the antennas 937 includes a single or multiple antenna elements
15 (such as multiple antenna elements included in an MIMO antenna), and is used for
the radio communication interface 933 to transmit and receive radio signals. The
car navigation apparatus 920 may include the ~nultiplea ntennas 937, as illustrated in
FIG. 27. Although FIG. 27 illustrates the example in which the car navigation
apparatus 920 includes the multiple antennas 937, the car navigation apparatus 920
20 may also include a single antenna 937.
[0243]
Furthermore, the car navigation apparatus 920 may include the antenna 937
for each radio communication scheme. In that case, the antenna svrritches 936 may
be omitted from the configuration of the car navigation apparatus 920.
25 [0244]
The battery 938 supplies power to blocks of the car navigation apparatus
920 illustrated in FIG. 27 via feeder lines that are partially shown as dashed lines in
the figure. The battery 938 accutnulates power supplied form the vehicle.
[0245]
30 In the car navigation apparatus 920 shown in FIG. 27, the inforll~ation
acquisition unit 261 and the cotiimunication control unit 263 that are described with
reference to FIG. 16 nlay be provided in the radio communication interface 933.
Also, at least a portion of these functions may be achieved by the processor 921.
[0246]
The technology of the present disclosure may also be realized as an in-
5 vehicle system (or a vehicle) 940 including one or more blocks of the car navigation
apparatus 920, the in-vehicle network 941, and a vehicle module 942. The vehicle
module 942 generates vehicle data such as vehicle speed, engine speed, and trouble
information, and outputs the generated data to the in-vehicle network 941.
[0247]
10 <<7. Conclusiod>
In the foregoing, a communicatio~a~p paratus according to an embodiment of
the present disclosure and functions thereof have been described with reference to
FIG. 1 to FIG. 27. According to an embodunent of the present disclosure, the
information acquisition unit 153 acquires a cell ID assigned to an individual three-
15 dimensional beam formed by a directional antenna capable of fonning a thseedilneilsio~
lal beam. Thereafter, the transmission control unit 155 controls
tsanstnission of a CRS performed using the individual three-dimensional beam, on
the basis of the cell ID assigned to the individual three-dimensional beam. In
particular, the trans~nission control unit 155 controls transmission of a CRS
20 performed using the individual thee-dimensional beam so tllat the CRS is
transmitted in a limited portion of available resource blocks.
[0248]
Such transmission of a CRS performed using a three-dimensional beam
allows for, for example, handling of a communication region corresponding to an
25 individual three-dimensional beam as a virtual cell. Therefore, load involved in
beamforming may be reduced. For example, it is not necessary to calculate a
recomme~lded set of weight coefficients for a three-dimensional beam for each
terminal apparatus 200. Therefore, even when the number of antenna elements
increases, the process of calculating a set of weight coefficients does not increase.
30 In other words, load can be reduced in tenns of the process of tile termitla1 apparatus
200 or the base station 100. Also, for example, it is not necessary to notify the base
station 100 of a reconmlended set of weight coefficients. Therefore, even when the
number of antenna elements increases, the notification of a recommended set of
weight coefficients do not have to use a large amount of radio resources. In other
words, load nlay be reduced in terms of radio resources.
S 102491
Moreover, for example, an increase in the interference can be reduced.
Specifically, for example, although, in the limited portion of resource blocks,
interference may occur between a CRS trar~smitted using a three-dimensional beam
formed by the base station 100 and a CRS transmitted in an adjacent cell, the
10 interference does not occur in resource blocks other than the limited portion of
resource blocks. Therefore, an increase in interference between the CRSs is
reduced.
[0250]
Therefore, according to an embodiment of the present disclosure, an
15 increase in the interference can be reduced while load involved in beamforming is
reduced.
[025 11
Also, for example, a decrease in transmission power for a non-directional
area can be reduced. Specifically, for example, the number of resource blocks in
20 which a CRS is transmitted is limited, and therefore, the number of CRSs transmitted
using a three-dimensional beam decreases, so that the power of transmission of CRSs
using a three-dimensional bean1 decreases. Therefore, a decrease in transmission
power for a non-directional area is reduced. As a result, a decrease in user
communication capacity, a decrease in throughput, and a decrease in cell size nlay
25 also be rednced.
[0252]
Transmission Of CRS In Resource Blocks Within Limited Period Of Time
The limited portion of resource blocks is, for example, a resource block or
resource blocks within a limited period of time. Also, the limited period of time is,
30 for exatnple, a limited portion of radio fianies. In other \\lords, a CRS is transnlitted
using a three-dimensional beam in a limited portion of radio frames.
102531
As a result, for example, although, during the limited period of time (radio
frames), interference may occur between a CRS transmitted using a threedimensional
beat11 formed by the base station 100 and a CRS transmitted in an
5 adjacent cell, the interference does not occur during a period of tirile other than the
litilited period of time. Therefore, an increase in interference between the CRSs is
.. limited to within a limited period of time.
[0254]
Also, for example, a period of time (radio frames) during which a CRS is
10 transmitted is limited, and therefore, allocation of power to transmission of a CRS
using a three-dimensional bean1 is limited to within a limited period of time (radio
frames). Therefore, a decrease in transmission power for a non-directional area is
limited to within a limited period of time. As a result, a decrease in user
communication capacity, a decrease in througliput, and a decrease in cell size may
15 also be limited to within a limited period of time.
[0255]
Moreover, for example, the limited portion of radio fiames is radio frames
determined for each cell, and is different fiotn a limited portion of radio fiatnes
determined for an adjacent cell.
20 [0256]
As a result, for example, interference between a CRS transmitted using a
three-dimensional beam formed by tlie base station 100 and a CRS transmitted using
a three-dimensional beam formed by a base station of an adjacent cell, can be
reduced.
25 [0257]
Note that, for exanlple, the transrnissio~i control unit 155 controls
transmission of information indicating the limited period of time (i.e., the first time
information).
[0258]
30 As a result, a terminal apparatus 200 can know a limited period of titne
(radio frames) during which a CRS is transn~itted using a three-dimensional beam.
Therefore, a tcrminal apparatus 200 can measure a CRS transn~itted during a limited
period of time (radio frames). In other wvords, measurenlcnt is appropriately
performed for a co~i~lnuriicatiorne gion (i.e., a virtual cell) corresponding to a threedin~
ensionabl eam. As a result, handover to a communication region corresponding
5 to a tluec-dimensional beam may be appropriately performed. Also, for example,
the consumption of power of a terminal apparatus 200 for measurement may also be
reduced.
[0259]
Transmission Of CRS In Resource Blocks Within Limited Frequency Band
10 The limited portion of resource blocks is, for example, a resource block or
resource blocks within a limited portion of an available frequency band. In other
words, a CRS is transmitted using a three-dimensional beam within a limited
frequency band.
[0260]
15 As a result, for example, although, within the limited frequency band,
interference may occur between a CRS transmitted using a three-dimensional beam
formed by the base station 100 and a CRS transmitted in an adjacent cell, the
interference does not occur within a frequency band other than the limited frequency
band. Therefore, an increase in interference between the CRSs is limited to within
20 a limited frequency band.
[0261]
Also, for example, a frequency band in which a CRS is transmitted is
limited, and therefore, allocation of power to transmission of a CRS using a threedimensional
beam is limited to within a limited frequency band. Therefore, a
25 decrease in transtnission power for a non-directional area per unit time (radio fian~e)
is redoced. As a result, a decrease in user cotnmunication capacity, a decrease in
throughput, and a decrease in cell size, per unit time (radio frame), may be reduced.
[0262]
Note that, for example, the tsansmission control unit 155 controls
30 transmission of a master information block (MIB) pcrfonned using an individual
three-dimensional beam. Tlic MIB contains infomiation indicating the bandwidth
of the limited frequency band (i.e., the first bandwidth infornlation).
[0263]
As a result, a terminal apparatus 200 located in a communication region
(virtual cell) corresponding to a three-dimensional beam can know a limited
5 fsequency band in wh'ich a CRS is transmitted, from the bandwidth information
contained in an MIB. Therefore, the terminal apparatus 200 can measure a CRS
transmitted in a limited frequency band. As a result, handover to a communication
region corresponding to a tlxee-dimensional barn may be appropriately performed.
[0264]
10 Moreover, for example, the transmission control unit 155 controls
transmission of a system information block (SIB) using an individual threedimensional
beam. The SIB contains information indicating the available
frequency band (is., the second bandwidth information).
[0265]
15 As a resalt, even whe11 information about the bandwidth of a limited
frequency band is contained in an MIB, a terminal apparatus 200 located in a
communication region (virtual cell) corresponding to a three-dimensional beam can
know an actual available frequency band from the bandwidth information contained
in an SIB. Therefore, the terminal apparatus 200 can perform radio communication
20 in an actual available frequency band using allocated radio resources.
[0266]
Transmission Of Other Signals Within Limited Period Of Time
For example, the transmission control unit 155 controls transmission of
system information pelfornled using an individual three-dimensional beam so that
25 the system information for the individual three-dimensional beam is transmitted
within a limited period of time.
[0267]
As a result, for example, altllough, during the limited period of time (radio
frames), interference may occur between a synchronization signal transmitted using a
30 three-dimensional beam formed by the base station 100 and a synchronization signal
transmitted in an adjacent cell, the interference does not occur during a period of
time other than the limited period of time. Therefore, an increase in interference
between the synchronization signals is limited to within a limited period of time.
[0268]
Also, for example, a period of time (radio frames) during which a
5 synclironization signal is transmitted is limited, and therefore, allocation of power to
transmission of a synchonization signal using a thee-dimensional beam is limited to
within a limited period of time (radio frames). Therefore, a decrease in
trausnlission power for a non-directional area is limited to within a limited period of
time. As a result, a decrease in user cormnunication capacity, a decrease in
10 throughput, and a decrease in cell size may also be limited to within a limited period
of time.
[0269]
Also, for example, the transmission cot~trolu nit 155 controls trat~smission
of system information perfortned using an individual three-dimensional beam so that
15 the system information for the individual three-dimensional beam is transmitted
within a limited period of time.
[0270]
As a result, for example, although, during the limited period of time (radio
fiames), interference may occur between system information transmitted using a
20 three-dimensional beatn formed by the base station 100 and system information
transmitted in an adjacent cell, the interference does not occur during a period of
time other than the limited period of time. Therefore, an increase in interference
between the pieces of system infornlation is limited to within a limited period of time.
[027 11
25 Also, for example, a period of time (radio fratnes) duriug which system
information is transmitted is limited, and therefore, allocatio~~of power to
transmissio~o~f system information using a three-diinensional beam is limited to
within a li~nited period of time (radio frames). Therefore, a decrease in
transnlissioli power for a non-directional area is limited to within a limited period of
30 time. As a result, a decrease in user communication capacity, a decrease it1
throughput, and a decrease in cell size may also be limited to within a limited period
of time.
[0272]
Resource Allocation Pattern Corlesponding To Cell ID
For example, the cell ID assigned to the individual thee-dinlensional bean1
5 and a cell ID assigned to an adjacent cell have different resource allocation patterns
for a CRS.
[0273]
As a result, even when a three-dimensional beam that may be formed by the
base station 100 reaches an adjacent cell, a CRS transmitted using the tlwee-
10 dimetisiorial beam does not interfere \with a CRS in an adjacent cell (non-directional
area). For example, thus, an increase in interference between the CRSs can be
reduced.
[0274]
The preferred embodiment(s) of the present disclosure hasihave been
15 described above with reference to the accompanying drawings, whilst the present
disclosure is not limited to the above examples. A person skilled in the art may find
various alterations and modifications within the scope of the appended claims, and it
should be understood that they will naturally come under the technical scope of the
present disclosure.
20 (02751
For example, an example in which beamforming is performed for downlink
has been described. The present disclosure is not lirnited to such an example. For
example, a beamfonning process may be performed for uplink. In other words, an
uplink beanlforming process may be performed on an uplink signal which is
25 transmitted to a terminal apparatus belonging to a communication region (virtual
cell) corresponding to a three-dimensional beam.
LO2761
Also, a frequency band used for a non-directional area and a frequency band
used for a directional area may be the same as or different i+om each other, or
30 overlap each otl~er. For example, a frequency band used for a non-directional area
and a frequency band used for a directional area may each be one or more component
carriers, and may be the sanxe as or different from each other, or overlap each other.
In any case, a component carrier used for a directional area tilay be the same as a
conlponent carrier used for a non-directional area (or a directional area) of an
adjacent cell.
5 LO2771
Also, an example in which the comtnunication system complies with LTE,
UTE-Advanced, or other similar conitnunication schemes, has been described. The
present disclosure is not limited to such an example. For example, the
co~ntiiunications ystem may comply with other comniunication standards.
10 LO2781
Also, the processing steps in a comnlunication control process in this
specification are not strictly limited to being executed in a time series following tlie
sequence described in a flowchart. For example, the processing steps in a
communication control process may be executed in a sequence that differs fiom a
15 sequence described herein as a flowchart, and fitrthennore may be executed in
parallel.
[0279]
In addition, it is possible to create a computer program for causing hardware
such as a CPU, ROM, and RAM built into a cotnmunication control device (a base
20 station device, for example) or a terniinal apparatus to exhibit functions similar to
each structural element of the foregoing commnunication control device or the
foregoing terminal apparatus. Also, a storage medium having such a computer
program stored therein may also be provided. Also, an information processing
device (for example, a processing circuit or chip) equipped with memory storing
25 such a computer program (for example, ROM and RAM) and one or inore processors
that may execute such a computer program (a CPU, a DSP, for example) may also be
provided.
(02801
In addition, tlie effects described in the present specification are merely
30 illustrative and demonstrative, and not limitative. In other words, the technology
according to the present disclosure can exhibit other effects that are evident to those
skilled in the art along with or instead of the effects based on the present
specification. .
[028 11
Additionally, the present technology may also be configured as belo\v.
5 (1)
A colnn~unicationc ontrol apparatus including:
an acquisition unit configured to acquire cell identification infor~nation
assigned to an individual three-dimensional beam formed by a directional antenna
capable of forming a three-dimensional beam; and
10 a control unit confignred to control transniission of a reference signal
performed using the individual three-dimensional beam, on the basis of the cell
identification information,
wherein the control unit controls the transtnission so that the reference
signal is transmitted in a limited portion of available resource blocks.
15 (2)
The co~innunicationc ontrol apparatus according to (I),
xvherein the limited portion of the available resource blocks is a resource
block or resource blocks within a limited period of time.
(3)
The comtnunication coritrol apparatus according to (2),
wherein the control unit controls transniission of system information
performed using the individual three-dimensional beam so that the system
information for the individual three-dinieasional beam is transmitted within a limited
period of time.
25 (4)
The con~municationc ontrol apparatus according to (2) or (3),
wherein the control uuit controls transmission of a synchronization signal
performed using the individual thee-dimensional beam so that the synchronizatio~i
signal for the individual thee-dimensional beam is transmitted ~vithiti a limited
30 period of time.
(5)
The conu~~unicatiocno ntrol apparatus according to any one of (2) to (4),
wherein the control unit controls transmission of inforn~ationin dicating the
limited period of time.
(6)
5 The communication control apparatus according to any one of (2) to ( S ) ,
wherein the limited period of time is determined for each cell, and is
different from a limited period of time determined for an adjacent cell.
(7)
The con~municationc ontrol apparatus according to any one of (2) to (6),
10 wherein the limited period of time is a limited portion of radio frames.
(8)
The communication control apparatus according to any ot~ocf (1) to (7),
wherein the limited portion of the available resource blocks is a resource
block or resource blocks within a limited pottion of an available frequency band.
15 (9)
The comn~unicationc ontrol apparatus according to (S),
wherein the control unit controls transmission of a master information block
performed using the individual three-dit~~ensionbaela m, and
wherein the master information block contains information indicating a
20 bandwidth of the limited portion of the available frequency band.
(1 0)
The communication control apparatus according to (9),
wherein the control unit controls transmission of a system information block
performed using the individual three-dimensional beam, and
25 wherein the system information block contains information indicating the
available frequency band.
(11)
The communication control apparatus according to any one of (1) to (lo),
wvherein the cell identification infor~nation is different from cell
30 identification information assigned to an adjacent cell, in a resource allocation
pattern for a reference signal.
The conlt~lullicationc ontrol apparatus according to any one of (1) to (ll),
wherein the control uuit controls transmission of infor~nationfo r specifying
the limited portion of the available resource blocks.
5 (13)
A co~nrnunicationc ontrol method including:
acquiring cell identification information assigned to an individual tlireedimensional
beam formed by a directional antenna capable of forming a threedimensional
beam; and
10 controlling, by a processor, tra~~slstnissioonf a reference sigual performed
using the individual three-dimensional beam, on the basis of the cell identification
information,
wherein the reference signal is transmitted in a limited portion of available
resource blocks.
15 (14)
A terminal apparatus including:
an acquisition unit configured to, when a base station configured to control
transmission of a reference signal performed using an individual three-dimensional
beam formed by a directional antenna capable of forming a three-dimensional beam,
20 on the basis of cell identification information assigned to the individual theedimensional
beam, transmits information for specifying a limited portion of available
resource blocks in which the reference signal is transmitted, acquire the information;
and
a conlmunication control tmit configured to measure the reference signal
25 transmitted in the limited portion of the available resource blocks.
(15)
The terminal apparatus according to (14),
wherein the limited portion of the available resource blocks is a resource
block or resource blocks within a limited period of time, and
30 whereiu the information for specifying the limited portion of the available
resource blocks contains information indicating the limited period of time.
The terniinal apparatus according to (14) or (15),
wherein the limited portion of the available resource blocks is a resource
block or resource blocks within a limited portion of an available frequency band, and
5 wherein the information for specifying the limited poltion of the available
resource blocks contains information indicating a bandwidth of the limited portion of
the available frequency hand.
(17)
The terniinal apparatus according to (16),
10 wherein information indicating the bandwidth of the limited portion of the
available frequency band is contained in a master information block transmitted
using the individual three-dimensional beam.
(18)
The terminal apparatus according to (17),
15 wherein the acquisition unit, when a system information block containing
information indicating the bandwidth of the available frequency band is transmitted
using the individual three-dimensional beani, acquires the information contained in
the system information block, and
wherein tlie communication control unit controls radio connnunication
20 performed by the terminal apparatus so that an allocated radio resource within the
available frequency band is used.
(19)
A co~nmunicationc ontrol method including:
when a base station configured to control ttra~~smissioonf a reference signal
25 perfonned using an individual three-dimensional beam formed by a directional
antenna capable of forn~ing a three-diniensional beani, on the basis of cell
identification information assigned to the individual three-dimensional beam,
transmits inforniation for specifying a li~nitedp ortion of available resource blocks it1
wliicli tlie reference signal is transmitted, acquiring the infor~nationa; nd ,
30 measuring, by a processol; the reference signal transmitted in the limited
portion of the available resource hlocks.
An information processing apparatus including:
a memory configured to store a program; aild
one or more processors capable of executing the program,
wherein the program executes
when a base station co~rfigured to control transmission of a
reference signal performed using an individual thee-dimensional beam formed by a
directional antenna capable of forming a three-dimensional beam, on the basis of cell
identification information assigned to the individual three-dimensional beam,
10 transmits information for specifying a limited portion of available resource blocks in
which the reference signal is transmitted, acquiring the information, and
measuring the reference signal transmitted in the limited portion of
the available resource blocks.
15 Reference Signs List
102821
1 comnunication system
10 cell
20 three-dinlensional beam
20 30 comniunication region
100 base station
151 cell ID assignment unit
153 information acquisition unit
155 transmission cotltrol unit
25 157 handover control unit
200 terminal apparatus
261 it~formationa cquisition unit
263 corn~nunicationc ontrol unit
CLAIMS
Claim 1
A communication control apparatus comprising:
an acq~~isitiounn it configured to acquire cell identification information
5 assigned to an individual thee-dimensional beam formed by a directional antenna
capable of forming a three-dimensional beam; and
a control unit configured to control trans~nission of a reference signal
performed using the individual thee-dimensional beam, on the basis of the cell
identification infornlation,
10 wherein the control unit controls the transmission so that the reference
signal is transmitted in a limited portion of available resource blocks.
Claitn 2
The communication control apparatus according to claim 1,
15 wherein the limited portion of the available resource blocks is a resource
block or resource blocks within a limited period of time.
Claim 3
The comtnunication control apparatus according to claim 2,
20 wherein the control unit controls transn~ission of system information
performed using the individual thee-dimensional beam so that the system
information for the individual three-dimensional beam is transmitted within a limited
period of time.
25 Claini 4
The con~mnnicatioc~oi ntrol apparatus according to clai~n2,
wherein the control unit controls transmission of a synchronizatio~s~ig nal
performed using the individual three-dimensional beam so that the synchonization
signal for the individual three-dimensional beam is trans~nitted within a limited
30 period of time.
Clai~i5l
The coms~~unicaticoosn~t rol apparatus according to claim 2,
wherein tlie control unit controls transmission of i~lforrilationi ndicating the
limited period of time.
5
Clai~i6l
The co~nmunicationc ontrol apparatus according to claim 2,
wherein the limited period of time is determined for each cell, and is
different from a limited period of time determined for an adjacent cell.
10
Claim 7
The conlmunication control apparatus according to claim 2,
wherein the limited period of time is a limited portion of radio frames.
15 Claim 8
The comtnut~icationc ontrol apparatus according to claim 1,
wherein the limited portion of the available resource blocks is a resource
block or resource blocks within a limited portion of an available fkequency band.
20 Claim 9
The communication control apparatus according to claim 8,
wherein the co~itroul nit controls transmission of a master information block
performed using the individual three-dimensional beam, and
wherein the master information block contains information indicating a
25 bandwidth of tlie limited portion of the available frequency band.
Claim 10
The comtnunication control apparatus according to claim 9,
wherein the co~ltroul nit controls transmission of a systenl infonnation block
30 performed using the individual three-dimensional beam, and
wherein the system information block contains information indicating the
available freqnency band.
Claim 11
Tlle communication control apparatus according to claim 1,
5 wherein the -cell idetitification information is different fi'om cell
identification inforn~ation assigned to an adjacent cell, in a resource allocation
pattern for a reference signal.
Claim 12
10 The co~ll~nunicatiocno ntrol apparatus according to claim 1,
wherein the col~troul nit controls transmission of information for specifying
the limited portion of the available resource blocks.
Claim 13
15 A commutiication control method coli~prising:
acquiring cell identification information assigned to an individual threedimetisional
beam folmed by a directional antenna capable of forming a threedimensional
beam; and
controlling, by a processor, tra~ismission of a reference signal performed
20 using the individual three-dimensional beam, on the basis of the cell identification
information,
wherein the reference signal is transmitted in a limited portion of available
resource blocks.
25 Claim 14
A terminal apparatus comprising:
an acquisition unit configured to, when a base station configured to control
transmission of a reference signal performed usitig an individual three-dimensional
beam formed by a directional antenna capable of forming a three-ditnensional beam,
30 on the basis of cell identification information assigned to the individual theedimensional
beam, transmits ilforlnation for specifying a limited portion of available
resource blocks in which the reference signal is tratlsn~itted,a cquire the information;
and
a communication control unit configured to measure the reference signal
transmitted in the limited portion of the available resource blocks.
5
Claim 15
The ternlinal apparatus according to claim 14,
wherein the limited portion of the available resource blocks is a resource
block or resource blocks within a linlited period of time, and
10 wherein the information for specifying the limited portion of the available
resource blocks contains information indicating the limited period of time.
Claim 16
The teiminal apparatus according to claim 14,
15 wherein the limited portion of the available resource blocks is a resource
block or resource blocks within a limited portion of an available frequency band, and
wherein the info~mation for specifying the limited portion of the available
resource blocks contains information indicating a bandwidth of the limited portion of
the available hequency band.
20
Claim 17
The terminal apparatus according to claim 16,
wherein informatiot~i ndicating the bandwidth of the limited portion of the
available frequency band is contained in a master information block transmitted
25 using the individual three-dimensional beam.
Claim 18
The ter~ninaal pparatus according to claim 17,
wherein the acquisition unit, when a system infornlation block containing
30 information indicating the bandwidth of the available frequency band is transmitted
using the individual three-dimensional beam, acquires the information contained in
the system information block, and
wherein the communication control unit controls radio communication
performed by the terminal apparatus so that an allocated radio resource within the'
available frequency band is used.
5
Claim 19
A communication control method comprising:
when a base station configured to control transmission of a reference signal
performed using an individual three-dimensional beam formed by a directional
10 antenna capable of forming a three-dimensional beam, on the basis of cell
identification information assigned to the individual three-dimensional beam,
transmits information for specifying a limited portion of available resource blocks in
which the reference signal is transmitted, acquiring the information; and
measuring, by a processor, the reference signal transmitted in the limited
15 portion of the available resource blocks.
Claim 20
An information processing apparatus comprising:
a memory configured to store a program; and
20 one or more processors capable of executing the program,
wherein the program executes
when a base station configured to control transmission of a
reference signal performed using an individual three-dimensional beam formed by a
directional antenna capable of forming a three-dimensional beam, on the basis of cell
25 identification information assigned to the individual three-dimensional beam,
transmits information for specifying a limited portion of available resource blocks in
which the reference signal is transmitted, acquiring the information, and
measuring the reference signal transmitted in the limited portion of
the available resource blocks.