Technical Field
[0001]
The present invention relates to a base station, a communication system, a
mobile terminal, and a relay device.
Background Art
[0002]
In 3GPP (Third Generation Partnership Project), a technology that uses a
relay device (relay station) to realize an increase in the throughput at the cell edge is
being actively considered.
[0003]
This relay device receives, in a downlink, a signal transmitted from a base
station, amplifies the same, and then transmits the amplified signal to a mobile
terminal. By performing such relaying, the relay device can increase the signal-tonoise
ratio than when directly transmitting a signal from the base station to the
mobile terminal. Similarly, in an uplink, the relay device can maintain high signalto-
noise ratio by relaying a signal transmitted from the mobile terminal to the base
station. Additionally, such relaying by the relay device is described in Non-Patent
Literature 1, for example.
[0004]
Furthermore, as a relay scheme of the relay device, an Amp-Forward type, a
Decode-Forward type, and the like can be cited. The Amp-Forward type is a
scheme of amplifying and transmitting a received signal while keeping it as an
analogue signal. According to this Amp-Forward type, although the signal-to-noise
ratio is not improved, there is an advantage that the conmiunication protocol does not
have to be refined. Additionally, the relay device has a feedback path between a
transmission anterma and a reception anterma, and is designed such that the feedback
path does not oscillate.
[0005]
The Decode-Forward tj^e is a scheme of converting a received signal to a
digital signal by AD conversion, performing decoding such as error correction on the
2
digital signal, encoding again the decoded digital signal, converting the digital signal
to an analogue signal by DA conversion, amplifying the analogue signal, and
transmitting the same. According to the Decode-Forward type, the signal-to-noise
ratio can be improved by a coding gain. Also, by storing a digital signal obtained
by reception in a memory and transmitting the digital signal in the next time slot, the
relay device can avoid oscillation of a feedback path between a transmission antenna
and a reception antenna. Additionally, the relay device is also capable of avoiding
the oscillation by changing the frequency instead of the time slot.
Citation List
Non-Patent Literature
[0006]
Non-Patent Literature 1: Panasonic, "Discussion on the TD relay and FD
relay for FDD system", November 10-14, 2008
Svimmary of hivention
Technical Problem
[0007]
However, in addition to a communication path going through the relay
device described above, there is also a communication path by which the base station
and the mobile terminal commimicate without the relay device. Accordingly, a case
is assumable where interference is caused between the communication path going
through the relay device and the communication path not going through the relay
device.
[0008]
Accordingly, the present invention is made in view of the above problem,
and the object of the present invention is to provide a base station, a communication
system, a mobile terminal, and a relay device which are novel and improved, and
which are capable of sharing communication resources between a communication
path going through a relay device and a communication path not going through a
relay device.
3
Solution to Problem
[0009]
According to an aspect of the present invention, in order to achieve the
above-mentioned object, there is provided a base station including a communication
unit for communicating with a mobile terminal via a relay link between the base
station and a relay device and an access link between the relay device and the mobile
terminal, or a direct link between the base station and the mobile terminal, and an
allocation imit for allocating an uplink and a downlink of each of the relay link, the
access link, and the direct link to resource blocks included in any of a plurality of
resource block groups, where the allocation unit allocates the downlink of the relay
link or the access link and the downlink of the direct link to a resource block
included in a same resource block group, and allocates the uplink of the relay link or
the access link and the uplink of the direct link to a resource block included in a same
resource block group.
[0010]
A first resource block group for the downlink of the relay link, a second
resource block group for the downlink of the access link, a third resource block
group for the uplink of the access link, and a fourth resource block group for the
uplink of the relay link may be different in at least time or frequency.
[0011]
The first resource block group may be same in frequency but different in
time from the second resource block group, and may be same in time but different in
frequency from the third resource block group, and the fourth resovirce block group
may be same in time but different in frequency from the second resource block group,
and may be same in frequency but different in time from the third resource block
group.
[0012]
The first reso\irce block group may be same in frequency but different in
time from the second resource block group, and may be same in time but different in
frequency from the fourth resource block group, and the third reso\irce block group
4
may be same in time but dififerent in frequency from the second resoiirce block group,
and may be same in frequency but dififerent in time from the fourth resource block
group.
[0013]
The first resource block group may be same in frequency but different in
time from the fourth resource block group, and may be same in time but different in
frequency from the third resource block group, and the second resource block group
may be same in time but different in frequency from the fourth resource block group,
and may be same in frequency but different in time from the third resource block
group.
[0014]
The first resource block group may be same in frequency but different in
time from the third resource block group, and may be same in time but different in
frequency from the fourth resource block group, and the second resource block group
may be same in time but different in frequency from the third resource block group,
and may be same in frequency but different in time from the fourth resource block
group.
[0015]
The first resource block group may be same in frequency but different in
time from the third resource block group, and may be same in time but different in
frequency from the second resource block group, and the fourth resource block group
may be same in time but different in frequency from the third resource block group,
and may be same in frequency but different in time from the second resource block
group.
[0016]
The first resource block group may be same in frequency but different in
time from the fourth resource block group, and may be same in time but different in
frequency from the second resource block group, and the third resource block group
may be same in time but different in frequency from the fourth resource block group,
and may be same in frequency but dififerent in time from the second resource block
group.
5
[0017]
The first resource block group, the second resource block group, the third
resource block group, and the fourth resource block group may be same in time but
different in fi^quency.
[0018]
The first resource block group, the second resource block group, the third
resource block group, and the fourth resource block group may be same in fi-equency
but different in time.
[0019]
According to another aspect of the present invention, in order to achieve the
above-mentioned object, there is provided a communication system including a
mobile terminal, a relay device, and a base station including a commvmication unit
for communicating with the mobile terminal via a relay link between the base station
and the relay device and an access link between the relay device and the mobile
terminal, or a direct link between the base station and the mobile terminal, and an
allocation imit for allocating an uplink and a downlink of each of the relay link, the
access link, and the direct link to resource blocks included in any of a plurality of
resource block groups, where the allocation unit allocates the downlink of the relay
link or the access link and the downlink of the direct link to a resource block
included in a same resource block group, and allocates the uplink of the relay link or
the access link and the uplink of the direct link to a resource block included in a same
resource block group.
[0020]
According to another aspect of the present invention, in order to achieve the
above-mentioned object, there is provided a mobile terminal. The mobile terminal
commvmicates with a base station using a resource block allocated by an allocation
unit, the base station including a conmiimication unit for corrmiunicating with the
mobile terminal via a relay link between the base station and a relay device and an
access link between the relay device and the mobile terminal, or a direct link between
the base station and the mobile terminal, and the allocation imit for allocating an
uplink and a downlink of each of the relay link, the access link, and the direct link to
6
resource blocks included in any of a plurality of resovirce block groups, where the
allocation unit allocates the downlink of the relay link or the access link and the
downlink of the direct link to a resource block included in a same resource block
group, and allocates the uplink of the relay link or the access link and the uplink of
the direct link to a resource block included in a same resource block group.
[0021]
According to another aspect of the present invention, in order to achieve the
above-mentioned object, there is provided a relay device. The relay device relays
communication between a base station and a mobile terminal using a resource block
allocated by an allocation unit, the base station including a communication unit for
communicating with the mobile terminal via a relay link between the base station and
the relay device and an access link between the relay device and the mobile terminal,
or a direct link between the base station and the mobile terminal, and the allocation
xmit for allocating an uplink and a downlink of each of the relay link, the access link,
and the direct link to resource blocks included in any of a plurality of resource block
groups, where the allocation unit allocates the dowiJink of the relay link or the
access link and the downlink of the direct link to a resource block included in a same
resource block group, and allocates the uplink of the relay link or the access link and
the uplink of the direct link to a resource block included in a same resource block
group.
Advantageous Effects of Invention
[0022]
As described above, according to the present invention, communication
resources can be shared between a comm\mication path going through a relay device
and a conmnmication path not going through a relay device.
Brief Description of Drawings
[0023]
[Fig. 1] Fig. 1 is an explanatory diagram showing a configuration of a
communication system according to an embodiment of the present invention.
7
[Fig. 2] Fig. 2 is an explanatory diagram showing each link in the communication
system according to the embodiment of the present invention.
[Fig. 3] Fig 3 is an explanatory diagram showing an example configuration of a radio
frame used in the communication system according to the embodiment.
[Fig. 4] Fig. 4 is a fimctional block diagram showing a configuration of a mobile
terminal.
[Fig. 5] Fig. 5 is a functional block diagram showing a configuration of a relay
device.
[Fig. 6] Fig. 6 is a functional block diagram showing a configuration of a base station.
[Fig. 7] Fig. 7 is an explanatory diagram showing an allocation pattern 1 for each
Imk.
[Fig. 8] Fig. 8 is an explanatory diagram showing an example of allocation where
uplinks and downlinks are present in a mixed manner in one resource block group.
[Fig. 9] Fig. 9 is an explanatory diagram showing an allocation pattern 2 for each
link.
[Fig. 10] Fig. 10 is an explanatory diagram showing an allocation pattern 3 for each
link.
[Fig. 11] Fig. 11 is an explanatory diagram showing an allocation pattern 4 for each
link.
[Fig. 12] Fig. 12 is an explanatory diagram showing an allocation pattern 5 for each
link.
[Fig. 13] Fig. 13 is an explanatory diagram showing an allocation pattern 6 for each
link.
[Fig. 14] Fig. 14 is an explanatory diagram showing an allocation pattern 7 for each
link.
[Fig. 15] Fig. 15 is an explanatory diagram showing an allocation pattern 8 for each
link.
[Fig. 16] Fig. 16 is a flow chart showing the flow of link allocation by a base station.
Description of Embodiments
[0024]
8
Hereinafter, preferred embodiments of the present invention will be
described in detail with reference to the appended drawings. Note that, in this
specification and the drawings, elements that have substantially the same fimction
and structure are denoted with the same reference signs, and repeated explanation is
omitted.
[0025]
Also, in this specification and the drawings, a plurality of structural
elements having substantially the same fimctional configuration may be
distinguished fi-om each other by each having a different letter added to the same
reference numeral. For example, a plurality of elements having substantially the
same functional configuration are distinguished fi-om each other as necessary as
mobile terminals 20A, 20B, and 20C. However, if it is not particularly necessary to
distinguish each of a plurality of structural elements having substantially the same
fimctional configviration, only the same reference nximeral is assigned. For example,
if it is not particularly necessary to distinguish between the mobile terminals 20A,
20B, and 20C, they are simply referred to as the mobile terminal 20.
[0026]
Furthermore, the "Description of Embodiments" will be described according
to the following item order.
1. Overview of Communication System
2. Configuration of Mobile Terminal
3. Configuration of Relay Device
4. Configuration of Base Station
5. Operation of Base Station
6. Summary
[0027]
<1. Overview of Conmiimication System>
First, a communication system 1 according to an embodiment of the present
invention will be briefly described with reference to Figs. 1 to 3. Fig. 1 is an
explanatory diagram showing the configuration of the commimication system 1
according to the embodiment of the present invention. As shown in Fig. 1, the
9
communication system 1 according to the embodiment of the present invention
includes a plurality of base stations 10A, lOB, and IOC, a backbone network 12, a
plurality of mobile terminals 20A, 20B, and 20C, and a plurality of relay devices 30A
and 30B.
[0028]
The plurality of base stations 10A, lOB, and IOC manage schedule
information for communicating with the mobile terminals 20 that are present in their
radio wave coverages. The pliirality of base stations lOA, lOB, and IOC
communicate with the mobile terminals 20 present in their radio wave coverages
according to the schedule information. For example, the base station lOA manages
schedule information on frequency-time for communicating with the mobile terminal
20C present in the radio wave coverage of the base station lOA. The base station
lOA communicates with the mobile terminal 20C present in the radio wave coverage
of the base station lOA according to the schedule information described above.
[0029]
Also, the plurality of base stations lOA, lOB, and IOC are also capable of
communicating with the mobile terminals 20 via relay devices 30 present in their
radio wave coverages. In this case, the plurality of base stations lOA, lOB, and IOC
manage schedule information for commxmicating with the relay devices 30, and
schedule information for the relay devices 30 and the mobile terminals 20 to
communicate with each other. For example, the base station lOA manages schedule
information on frequency-time for communicating with a relay device 30A present in
the radio wave coverage of the base station 10A, and manages schedule information
on frequency-time for the relay device 30A and the mobile terminals 20A and 20B to
communicate with each other. The base station lOA communicates with the relay
device 30A according to the schedule information described above.
[0030]
Additionally, in the present specification, an explanation will be given
placing emphasis on a case where frequency-time schedule management is
performed by the base station 10, but the present invention is not limited to such an
example. For example, the frequency-time schedule management may be
10
performed by the base station 10 and the relay device 30 working in cooperation with
each other, or may be performed by the base Station 10, the relay device 30, and the
mobile terminal 20 working in cooperation with each other, or may be performed by
the relay device 30.
[0031]
Furthermore, the plurality of base stations lOA, lOB, and IOC are connected
via the backbone network 12. The plurality of base stations 10 A, lOB, and IOC are
capable of exchanging the schedule information that each manages via this backbone
network 12, for example.
[0032]
The relay device 30 relays the communication between the base station 10
and the mobile terminal 20 according to the schedule information on frequency-time
managed by the base station 10. Specifically, in the downlink, the relay device 30
receives a signal transmitted from the base station 10, and transmits the amplified
signal to the mobile terminal 20 using the frequency-time that is according to the
schedule information. By performing such relaying, the relay device 30 can
increase the signal-to-noise ratio than when directly transmitting the signal from the
base station 10 to the mobile terminal 20 near the cell edge.
[0033]
Similarly, also in the uplink, the relay device 30 relays a signal transmitted
from the mobile terminal 20 to the base station 10 according to the schedule
information on frequency-time managed by the base station 10, and thereby
maintains a high signal-to-noise ratio. Additionally, an example is shown in Fig. 1
where only the relay device 30A is present in the cell provided by the base station
10A, but a plurality of relay devices 30 may be present in the cell provided by the
base station 10A. Link names will now be organized with reference to Fig. 2.
[0034]
Fig. 2 is an explanatory diagram showing each link in the communication
system 1 according to the embodiment of the present invention. As shown in Fig. 2,
a direct communication path between the base station 10 and the mobile terminal 20
is referred to as a direct link. Also, the downlink of this direct link is referred to as
11
a direct downlink (D-d), and the uplink of this direct link is referred to as a direct
uplink (D-u).
[0035]
Also, the communication path between the base station 10 and the reliay
device 30 is referred to as a relay link, and the downlink of this relay link is referred
to as a relay downlink (R-d), and the uplink of this relay link is referred to as a relay
uplink (R-u). Furthermore, the communication path between the relay device 30
and the mobile terminal 20 is referred to as an access link, and the downlink of this
access link is referred to as an access downlink (A-d), and the uplink of this access
link is referred to as an access uplink (A-u).
[0036]
The communication system 1 will be again described with reference to Fig.
1. As described above, the mobile terminal 20 included in the communication
system 1 communicates with the base station 10 directly or via the relay device 30,
according to the schedule information managed by the base station 10. Additionally,
as the data to be transmitted/received by the mobile terminal 20, audio data, music
data such as music, a lecture, a radio program, or the like, still image data such as a
photograph, a document, a painting, a diagram, or the like, video data such as a
movie, a television program, a video program, a game image, or the like, may be
cited.
[0037]
Now, the configuration of a radio fi^me used in the commxmication system
1 according to the present embodiment will be described with reference to Fig. 3.
Fig. 3 is an explanatory diagram showing an example configuration of a radio fi^me
used in the communication system 1 according to the present embodiment. As
shown in Fig. 3, the length of each radio fi-ame is 10 ms. Also, each radio fi-ame is
formed fi-om ten subfi^mes #0 to #9 whose lengths are 1 ms. Also, each subfi"ame
is formed fi-om two 0.5ms slots, and each 0.5ms slot is formed from seven OFDM
(orthogonal frequency division multiplexing) symbols.
[0038]
Also, the fifth and sixth OFDM symbols of the first 0.5ms slots included in
12
the subframes #0 and #5 are used for transmission of reference signals for
synchronization. The mobile terminal 20 performs a cell search and a
synchronization process based on this reference signal transmitted from the base
station 10 or the relay device 30.
[0039]
Additionally, the base station 10 allots time on a per-0.5ms slot basis for
communication with the mobile terminal 20. Furthermore, to separate the uplink
and the downlink, FDD (Frequency Division Duplex) and TDD (Time Division
Duplex) are used. In the case of TDD, it is possible to select for each subframe
whether to vise the subframe for uplink or downlink.
[0040]
<2. Configuration of Mobile Terminal>
In the foregoing, the commimication system 1 according to the present
embodiment has been briefly described with reference to Figs. 1 to 3. Next, the
configuration of the mobile terminal 20 included in the communication system 1
according to the present embodiment will be described with reference to Fig. 4. Fig.
4 is a fimctional block diagram showing the configuration of the mobile terminal 20.
As shown in Fig. 4, the mobile terminal 20 includes a plurality of anteimas 220a to
220n, an analogue processing unit 224, an AD/DA converter 228, and a digital
processing unit 230.
[0041]
Each of the plurality of antennas 220a to 220n receives a radio signal from
the base station 10 or the relay device 30 and acquires an electrical high-frequency
signal, and supplies the high-frequency signal to the analogue processing unit 224.
Also, each of the plurality of antennas 220a to 220n transmits a radio signal to the
base station 10 or the relay device 30 based on the high-frequency signal supplied
from the analogue processing unit 224. Since the mobile terminal 20 is provided
with the plurality of antennas 220a to 220n as described, it is capable of performing
MIMO (Miiltiple Input Multiple Output) conmiunication or diversity commimication.
[0042]
The analogue processing imit 224 converts the high-frequency signals
13
supplied from the plurality of antennas 220a to 220n into baseband signals by
performing analogue processing such as amplification, filtering, down-conversion, or
the like. Also, the analogue processing unit 224 converts a baseband signal
supplied from the AD/DA converter 228 into a high-frequency signal.
[0043]
The AD/DA converter 228 converts the analogue baseband signal supplied
from the analogue processing unit 224 into a digital format, and supplies the same to
the digital processing unit 230. Also, the AD/DA converter 228 converts a digital
baseband signal supplied from the digital processing unit 230 into an analogue
format, and supplies the same to the analogue processing unit 224.
[0044]
The digital processing unit 230 includes a synchronization unit 232, a
decoder 234, a SINR (Signal to Interference plus Noise Ratio) acquisition xmit 236, a
transmission data generation unit 238, an encoder 240, a control vmit 242, and a
schedule information holding unit 244. Among these, the synchronization unit 232,
the decoder 234, the encoder 240, and the like ftinction, together with the plurality of
antennas 220a to 220n, the analogue processing imit 224, and the AD/DA converter
228, as a comm\mication unit for communicating with the base station 10 and the
relay device 30.
[0045]
The synchronization unit 232 is supplied, from the AD/DA converter 228,
with a reference signal transmitted from the base station 10 or the relay device 30,
and performs a synchronization process of a radio frame based on the reference
signal. Specifically, the synchronization unit 232 performs synchronization of the
radio frame by computing the correlation between the reference signal and a known
sequence pattern and detecting the peak position of the correlation.
[0046]
The decoder 234 decodes a baseband signal supplied from the AD/DA
converter 228 and obtains received data. Additionally, the decoding may include a
MIMO reception process and an OFDM demodulation process, for example.
[0047]
14
The SINR acquisition unit 236 acquires the level of SINR with respect to
the relay device 30 from the correlation of the reference signal obtained by the
synchronization unit 232. Here, each relay device 30 transmits a reference signal
having any of a plurality of sequence patterns. Therefore, the SINR acquisition unit
236 can acquire the SINR for each relay device 30 based on the difference between
the sequence patterns of the reference signals.
[0048]
The transmission data generation unit 238 is supplied, from the SINR
acquisition unit 236, with information indicating the SINR of each relay device 30,
and generates transmission data including the information and supplies the same to
the encoder 240.
[0049]
The encoder 240 encodes the transmission data supplied from the
transmission data generation unit 238, and supplies the same to the AD/DA converter
228. Additionally, the encoding may include a MIMO transmission process and an
OFDM demodulation process, for example.
[0050]
The control unit 242 controls transmission processing and reception
processing at the mobile terminal 20 according to the schedule information held in
the schedule information holding unit 244. For example, the mobile terminal 20
performs, based on the control of the control unit 242, transmission processing and
reception processing using resource blocks indicated by the schedule information.
[0051]
The schedule information holding unit 244 holds the schedule information
managed by the base station 10. This schedule information indicates a resource
block to be used for the access downlink or a resovirce block to be used for the access
uplink, for example.
[0052]
Additionally, the schedule information of the uplink and the downlink is
included in a PDCH (Physical Downlink Control Channel) which is a downlink
control channel. Also, this PDCH is transmitted using the first one to three OFDM
15
symbols of a subframe, in the radio frame, allocated to the downlink.
[0053]
<3. Configuration of Relay DevicO
Next, the configuration of the relay device 30 will be described with
reference to Fig. 5. Fig. 5 is a fimctional block diagram showing the configviration
of the relay device 30. As shown in Fig. 5, the relay device 30 includes a plurality
of antennas 320a to 320n, an analogue processing unit 324, an AD/DA converter 328,
and a digital processing unit 330.
[0054]
Each of the plurality of antennas 320a to 320n receives a radio signal from
the base station 10 or the mobile terminal 20 and acquires an electrical highfrequency
signal, and supplies the high-frequency signal to the analogue processing
unit 324. Also, each of the plurality of antennas 320a to 320n transmits a radio
signal to the base station 10 or the mobile terminal 20 based on the high-frequency
signal supplied from the analogue processing unit 324. Since the relay device 30 is
provided with the plurality of antermas 320a to 320n as described, it is capable of
performing MIMO communication or diversity communication.
[0055]
The analogue processing unit 324 converts the high-frequency signals
supplied from the plurality of anteimas 320a to 320n into baseband signals by
performing analogue processing such as amplification, filtering, down-conversion, or
the like. Also, the analogue processing imit 324 converts a baseband signal
supplied from the AD/DA converter 328 into a high-frequency signal.
[0056]
The AD/DA converter 328 converts the analogue baseband signal supplied
from the analogue processing unit 324 into a digital format, and supplies the same to
the digital processing unit 330. Also, the AD/DA converter 328 converts a digital
baseband signal supplied from the digital processing unit 330 into an analogue
format, and supplies the same to the analogue processing unit 324.
[0057]
The digital processing unit 330 includes a synchronization imit 332, a
16
decoder 334, a buffer 338, an encoder 340, a control unit 342, and a schedule
information holding unit 344. Among these, the synchronization unit 332, the
decoder 334, the encoder 340, and the like function, together with the plurality of
antennas 320a to 320n, the analogue processing unit 324, and the AD/DA converter
328, as a communication unit for communicating with the base station 10 and the
mobile terminal 20.
[0058]
The synchronization unit 332 is supplied, from the AD/DA converter 328,
with a reference signal transmitted from the base station 10, and performs a
synchronization process of a radio frame based on the reference signal. Specifically,
the synchronization unit 332 performs synchronization of the radio frame by
computing the correlation between the reference signal and a known sequence
pattern and detecting the peak position of the correlation.
[0059]
The decoder 334 decodes a baseband signal supplied from the AD/DA
converter 328 and obtains relay data for the base station 10 or the mobile terminal 20.
Additionally, the decoding may include a MIMO reception process, an OFDM
demodulation process, an error correction process, and the like, for example.
[0060]
The buffer 338 temporarily holds the relay data, obtained by the decoder
334, for the base station 10 or the mobile terminal 20. Then, the relay data for the
mobile terminal 20 is read out, by the control of the control unit 342, from the buffer
338 to the encoder 340 in the transmission time of the access downlink to the mobile
terminal 20. Likewise, the relay data for the base station 10 is read out, by the
control of the control unit 342, from the buffer 338 to the encoder 340 in the
transmission time of the relay uplink to the base station 10.
[0061]
The encoder 340 encodes the data supplied from the buffer 338, and
supplies the same to the AD/DA converter 328. Additionally, the encoding may
include a MIMO transmission process and an OFDM demodulation process, for
example.
17
[0062]
The control unit 342 controls transmission processing and reception
processing at the relay device 30 according to the schedule information held in the
schedule information holding unit 344. For example, the relay device 30 performs,
based on the control of the control unit 342, transmission processing and reception
processing using resource blocks indicated by the schedule information.
[0063]
The schedule information holding xmit 344 holds the schedule information
managed by the base station 10. This schedule information indicates resource
blocks to be used respectively for the relay downlink, the access downlink, the access
uplink, and the relay uplink, for example.
[0064]
<4. Configuration of Base Station>
Next, the configuration of the base station 10 will be described with
reference to Figs. 6 to 16.
[0065]
Fig. 6 is a functional block diagram showing the configuration of the base
station 10. As shown in Fig. 6, the base station 10 includes a plurality of antennas
120a to 120n, an analogue processing unit 124, an AD/DA converter 128, and a
digital processing unit 130.
[0066]
Each of the plurality of antennas 120a to 120n receives a radio signal fi"om
the relay device 30 or the mobile terminal 20 and acquires an electrical highfi-
equency signal, and supplies the high-frequency signal to the analogue processing
unit 124. Also, each of the plurality of anteimas 120a to 120n transmits a radio
signal to the relay device 30 or the mobile terminal 20 based on the high-frequency
signal supplied from the analogue processing unit 124. Since the base station 10 is
provided with the plurality of antennas 120a to 120n as described, it is capable of
performing MIMO commimication or diversity communication.
[0067]
The analogue processing unit 124 converts the high-frequency signals
18
supplied from the plvirality of antennas 120a to 120n into baseband signals by
performing analogue processing such as amplification, filtering, down-conversion, or
the like. Also, the analogue processing unit 124 converts a baseband signal
supplied from the AD/DA converter 128 into a high-frequency signal.
[0068]
The AD/DA converter 128 converts the analogue baseband signal supplied
from the analogue processing unit 124 into a digital format, and supplies the same to
the digital processing unit 130. Also, the AD/DA converter 128 converts a digital
baseband signal supplied from the digital processing unit 130 into an analogue
format, and supplies the same to the analogue processing imit 124.
[0069]
The digital processing imit 130 includes a decoder 134, a transmission data
generation unit 138, an encoder 140, a control unit 142, a schedule information
holding unit 144, and a scheduler 156. Among these, the decoder 134, the encoder
140, and the like fimction, together with the plurality of anteimas 120a to 120n, the
analogue processing imit 124, and the AD/DA converter 128, as a conmiunication
unit for coirmiimicating with the relay device 30 and the mobile terminal 20.
[0070]
The decoder 134 decodes a baseband signal supplied from the AD/DA
converter 128 and obtains received data. Additionally, the decoding may include a
MIMO reception process, an OFDM demodulation process, an error correction
process, and the like, for example.
[0071]
The transmission data generation imit 138 generates transmission data
including schedule information scheduled by the scheduler 156. Additionally, the
schedule information is included in the PDCH arranged at the begiiming of the
subframes as described above.
[0072]
The encoder 140 encodes the transmission data supplied from the
transmission data generation unit 138, and supplies the same to the AD/DA converter
128. Additionally, the encoding may include a MIMO transmission process and an
19
OFDM demodulation process, for example.
[0073]
The control unit 142 controls transmission processing and reception
processing at the base station 10 according to the schedule information held in the
schedule information holding unit 144. For example, the base station 10 performs,
based on the control of the control imit 142, transmission processing and reception
processing using resource blocks indicated by the schedule information.
[0074]
The schedule information holding unit 144 holds the schedule information
determined by the scheduler 156.
[0075]
The scheduler 156 (allocation unit) schedules relay link communication
with the relay device 30, access link commimication between the relay device 30 and
the mobile terminal 20, and direct link conmiunication with the mobile terminal 20.
[0076]
More particularly, the scheduler 156 performs resource allocation for the
relay downlink, the access downlink, the access uplink, the relay uplink, the direct
downlink, and the direct uplink according to one of a plurality of allocation patterns.
[0077]
For example, the scheduler 156 allocates to the relay downlink, the access
downlink, the access uplink and the relay uplink resource blocks included in different
resource block groups. Also, the scheduler 156 allocates the direct uplink to a
resource block included in the same resource block group as the relay uplink or the
access uplink. Similarly, the scheduler 156 allocates the direct downlink to a
resource block included in the same resource block group as the relay downlink or
the access downlink. In the following, the allocation pattern for each link by the
scheduler 156 will be specifically described with reference to Fig. 7 and subsequent
drawings.
[0078]
(Allocation Pattern 1)
Fig. 7 is an explanatory diagram showing an allocation pattern 1 for each
20
link. As shown in Fig. 7, according to the allocation pattern 1, the relay downlink
(R-d) is allocated to a resource block group defined by fi-equency F2 - time Tl, the
access downlink (A-d) is allocated to a resource block group defined by fi^equency
F2 - time T2, the access uplink (A-u) is allocated to a resource block group defined
by fi-equency Fl - time Tl, and the relay uplink (R-u) is allocated to a resource block
group defined by fi-equency Fl - time T2.
[0079]
According to this allocation pattern 1, the base station 10 transmits data to
the relay device 30 via the relay downlink in a resource block included in the
resource block group defined by fi-equency F2 - time Tl. Then, the relay device 30
receives the data transmitted via the relay downlink, holds it in the buffer 338 as
relay data, and then transmits the relay data to the mobile terminal 20 via the access
downlink in a resource block included in the resource block group defined by
fi-equency F2 - time T2.
[0080]
Also, the mobile terminal 20 transmits data to the relay device 30 via the
access uplink in a resource block included in the resource block group defined by
fi-equency Fl - time Tl. Then, the relay device 30 receives the data transmitted via
the access uplink, holds it in the buffer 338 as relay data, and then transmits the relay
data to the base station 10 via the relay uplink in a resource block included in the
resource block group defined by fi-equency Fl - time T2.
[0081]
In this manner, according to the allocation pattern 1, the uplink and the
downlink are separated by frequency, and the relay link and the access link in the
same direction are separated by time, and thus interference between each link can be
suppressed.
[0082]
Additionally, as shown in Fig. 7, one resource block group is formed from a
plurality of resource blocks. Also, one resource block is formed from twelve
subcarriers and a 0.5ms slot (seven OFDM symbols), for example. This resoiirce
block is a unit of link allocation for each channel. Accordingly, a plurality of
21
channels can be multiplexed in one resource block group in the time direction and
the frequency direction.
[0083]
Furthermore, according to the allocation pattern 1, the direct downlink (D-d)
is allocated to the same resource block group as the relay downlink (R-d) and to the
same resource block group as the access downlink (A-d). On the other hand, the
direct uplink (D-u) is allocated to the same resource block group as the relay uplink
(R-u) and to the same resource block group as the access uplink (A-u).
[0084]
The reason for allocating the direct downlink to the same resource block
group as another downlink and allocating the direct uplink to the same resource
block group as another uplink will be described.
[0085]
In LTE (Long Term Evolution), each mobile terminal 20 shares and uses the
communication resources on a per-resource block basis. Also, each mobile terminal
20 shares a downlink resource block group for downlink and shares an uplink
resource block group for uplink, according to the scheduling by the scheduler 156 of
the base station 10.
[0086]
That is, in LTE, the same resource block group is not shared between both
the uplink and the downlink. This is because the base station and the mobile
terminal normally have configurations not allowing the uplink and the downlink to
be present in the same resource block group in a mixed manner.
[0087]
On the other hand, when introducing the relay device 30, resources are
preferably shared between the relay link and the direct link or between the access
link and the direct link. Here, if operating in the same way as LTE, the scheduler
156 is capable of changing the resource distribution for the downlink in the downlink
resource block group and the resource distribution for the uplink in the uplink
resource block group.
[0088]
22
Accordingly, in the present embodiment, the direct downlink is allocated to
the same resource block group as another downlink and the direct uplink is allocated
to the same resource block group as another uplink, as described above.
Additionally, in contrast, it is difficult to share the resources by performing allocation
as shown in Fig. 8.
[0089]
Fig. 8 is an explanatory diagram showing an example of allocation where
the uplink and the downlink are present in the same resource block group in a mixed
manner. In the example shown in Fig. 8, the uplink and the downlink are present in
a mixed manner in each of a resource block group defined by frequency F2 - time Tl,
a resource block group defined by frequency F2 - time T2, a resource block group
defined by frequency Fl - time Tl, and a resource block group defined by frequency
Fl - time T2. However, sharing of such communication resources is difficult.
[0090]
In the following, other allocation patterns 2 to 8 according to the present
embodiment will be described with reference to Figs. 9 to 15.
[0091]
(Allocation Pattern 2)
Fig. 9 is an explanatory diagram showing an allocation pattern 2 for each
link. As shown in Fig. 9, according to the allocation pattern 2, the access downlink
(A-d) is allocated to the resource block group defined by frequency F2 - time Tl, the
relay downlink (R-d) is allocated to the resource block group defined by frequency
F2 - time T2, the access uplink (A-u) is allocated to the resource block group defined
by frequency Fl - time Tl, and the relay uplink (R-u) is allocated to the resource
block group defined by frequency Fl - time T2.
[0092]
According to this allocation pattern 2, the relay device 30 transmits relay
data held in the buffer 338 to the mobile terminal 20 via the access downlink in a
resource block included in the resource block group defined by frequency F2 - time
Tl. Also, the base station 10 transmits data to the relay device 30 via the relay
downlink in a resource block included in the resource block group defined by
23
frequency F2 - time T2.
[0093]
Also, the mobile terminal 20 transmits data to the relay device 30 via the
access uplink in a resoiirce block included in the resource block group defined by
frequency Fl - time Tl. Then, the relay device 30 receives the data transmitted via
the access uplink, holds it in the buffer 338 as relay data, and transmits the relay data
to the base station 10 via the relay uplink in a resource block included in the resource
block group defined by frequency Fl - time T2.
[0094]
In this manner, according to the allocation pattern 2, the uplink and the
downlink are separated by frequency, and the relay link and the access link in the
same direction are separated by time, and thus interference between each link can be
suppressed.
[0095]
Furthermore, according to the allocation pattern 2, the direct downlink (D-d)
is allocated to the same resource block group defined by frequency F2 - time T2 as
the relay downlink (R-d) and is allocated to the same resource block group defined
by frequency F2 - time Tl as the access downlink (A-d).
[0096]
Similarly, the direct uplink (D-u) is allocated to the same resource block
group defined by frequency Fl - time T2 as the relay uplink (R-u) and the same
resource block group defined by frequency Fl - time Tl as the access uplink (A-u).
[0097]
By performing link allocation according to the allocation pattern 2 in this
manner, a resource block group (communication resources) can be shared between
the relay link or the access link and the direct link.
[0098]
(Allocation Pattern 3)
Fig. 10 is an explanatory diagram showing an allocation pattern 3 for each
link. As shown in Fig. 10, according to the allocation pattern 3, the relay downlink
(R-d) is allocated to the resource block group defined by frequency F2 - time Tl, the
24
access downlink (A-d) is allocated to the resource block group defined by frequency
Fl - time T2, the access uplink (A-u) is allocated to the resource block group defined
by frequency Fl - time Tl, and the relay uplink (R-u) is allocated to the resource
block group defined by frequency F2 - time T2.
[0099]
According to this allocation pattern 3, the base station 10 fransmits data to
the relay device 30 via the relay downlink in a resource block included in the
resource block group defined by frequency F2 - time Tl. Then, the relay device 30
receives the data transmitted via the relay downlink, holds it in the buffer 338 as
relay data, and then fransmits the relay data to the mobile terminal 20 via the access
downlink in a resource block included in the resource block group defined by
frequency Fl - time T2.
[0100]
Furthermore, the mobile terminal 20 transmits data to the relay device 30
via the access uplink in a resource block included in the resource block group
defined by frequency Fl - time Tl. Then, the relay device 30 receives the data
transmitted via the access uplink, holds it in the buffer 338 as relay data, and then
transmits the relay data to the base station 10 via the relay uplink in a resource block
included in the resource block group defined by frequency F2 - time T2.
[0101]
In this manner, according to the allocation pattern 3, the uplink and the
downlink are separated by frequency, and the relay link and the access link in the
same direction are separated by both frequency and time, and thiis interference
between each link can be suppressed.
[0102]
Furthermore, according to the allocation pattern 3, the direct downlink (D-d)
is allocated to the same resource block group defined by frequency F2 - time Tl as
the relay downlink (R-d) and the same resource block group defined by frequency Fl
- time T2 as the access downlink (A-d).
[0103]
Similarly, the direct uplink (D-u) is allocated to the same resource block
25
group defined by fi-equency F2 - time T2 as the relay uplink (R-u) and the same
resource block group defined by frequency Fl - time Tl as the access uplink (A-u).
[0104]
By performing link allocation according to the allocation pattern 3 in this
manner, a resource block group can be shared between the relay link or the access
link and the direct link.
[0105]
(Allocation Pattern 4)
Fig. 11 is an explanatory diagram showing an allocation pattern 4 for each
link. As shown in Fig. 11, according to the allocation pattern 4, the relay downlink
(R-d) is allocated to the resource block group defined by fi-equency F2 - time Tl, the
access downlink (A-d) is allocated to the resource block group defined by fi-equency
Fl - time T2, the access uplink (A-u) is allocated to the resource block group defined
by fi-equency F2 - time T2, and the relay uplink (R-u) is allocated to the resource
block group defined by fi-equency Fl - time Tl.
[0106]
According to this allocation pattern 4, the base station 10 transmits data to
the relay device 30 via the relay downlink in a resource block included in the
resource block group defined by fi-equency F2-time Tl. Then, the relay device 30
receives the data transmitted via the relay downlink, holds it in the buffer 338 as
relay data, and then transmits the relay data to the mobile terminal 20 via the access
downlink in a resource block included in the resource block group defined by
fi-equency Fl - time T2.
[0107]
Furthermore, the relay device 30 transmits the relay data held in the biiffer
338 to the base station 10 via the relay uplink in a resource block included in the
resource block group defined by fi-equency Fl - time Tl. Also, the mobile terminal
20 transmits data to the relay device 30 via the access uplink in a resource block
included in the resource block group defined by fi-equency F2 - time T2.
[0108]
In this manner, also according to the allocation pattern 4, the uplink and the
26
downlink are separated by frequency, and the relay link and the access link in the
same direction are separated by both frequency and time, and thus interference
between each link can be suppressed.
[0109]
Furthermore, according to the allocation pattern 4, the direct downlink (D-d)
is allocated to the same resource block group defined by frequency F2 - time Tl as
the relay downlink (R-d) and the same resource block group defined by frequency Fl
- time T2 as the access downlink (A-d).
[0110]
Similarly, the direct uplink (D-u) is allocated to the same resource block
group defined by frequency Fl - time Tl as the relay uplink (R-u) and the same
resource block group defined by frequency F2 - time T2 as the access uplink (A-u).
[0111]
By performing link allocation according to the allocation pattern 4 in this
maimer, a resource block group can be shared between the relay link or the access
link and the direct link.
[0112]
(Allocation Pattern 5)
Fig. 12 is an explanatory diagram showing an allocation pattern 5 for each
link. As shown in Fig. 12, according to the allocation pattern 5, the relay downlink
(R-d) is allocated to the resource block group defined by frequency Fl - time Tl, the
access downlink (A-d) is allocated to the resource block group defined by frequency
F2 - time Tl, the access uplink (A-u) is allocated to the resource block group defined
by frequency Fl - time T2, and the relay uplink (R-u) is allocated to the resource
block group defined by frequency F2 - time T2.
[0113]
As described above, unlike the allocation patterns 1 to 4, according to the
allocation pattern 5, the relay link and the access link are separated by frequency.
Accordingly, the delay that occurs between the downlink of the relay link and the
downlink of the access link can be reduced from a per-slot basis to a per-OFDMsymbol
basis. Likewise, the delay that occurs between the uplink of the access link
27
and the uplink of the relay link can be reduced from a per-slot basis to a per-OFDMsymbol
basis.
[0114]
Specifically, the base station 10 transmits data to the relay device 30 via the
relay downlink in a resource block included in the resource block group defined by
frequency Fl - time Tl. Then, the relay device 30 performs, using a resource block
included in the resource block group defined by frequency F2 - time Tl, decoding,
buffering, encoding, and transmission to the mobile terminal 20 via the access
downlink of data received via the relay downlink, with the amount of delay on a per-
OFDM-symbol basis from the reception. Additionally, the amount of delay may be
variable between one OFDM symbol to a plurality of OFDM symbols.
[0115]
Also, the mobile terminal 20 transmits data to the relay device 30 via the
access uplink in a resource block included in the resource block group defined by
frequency Fl - time T2. Then, the relay device 30 performs, using a resoiu*ce block
included in the resource block group defined by frequency F2 - time T2, decoding,
buffering, encoding, and transmission to the base station 10 via the relay uplink of
data received via the access uplink, with the amoimt of delay on a per-OFDMsymbol
basis from the reception.
[0116]
As described, according to the allocation pattern 5, the relay link and the
access link are separated by frequency (FDD), and the uplink and the downlink are
separated by time (TDD). Therefore, according to the allocation pattern 5, the
delay that occurs between the base station 10 and the mobile terminal 20 can be
reduced compared to the allocation patterns 1 to 4 where the relay link and the access
link are separated by time, while suppressing the interference between each link.
[0117]
Furthermore, according to the allocation pattern 5, the direct downlink (D-d)
is allocated to the same resource block group defined by frequency Fl - time Tl as
the relay downlink (R-d) and the same resource block group defined by frequency F2
- time Tl as the access downlink (A-d).
28
[0118]
Similarly, the direct uplink (D-u) is allocated to the same resource block
group defined by fi-equency F2 - time T2 as the relay uplink (R-u) and the same
resource block group defined by fi-equency Fl - time T2 as the access uplink (A-u).
[0119]
By performing link allocation according to the allocation pattern 5 in this
manner, a resource block group can be shared between the relay link or the access
link and the direct link.
[0120]
(Allocation Pattern 6)
Fig. 13 is an explanatory diagram showing an allocation pattern 6 for each
link. As shown in Fig. 13, according to the allocation pattern 6, the relay downlink
(R-d) is allocated to the resource block group defined by fi^equency Fl - time Tl, the
access downlink (A-d) is allocated to the resource block group defined by fi-equency
F2 - time Tl, the access uplink (A-u) is allocated to the resource block group defined
by fi-equency F2 - time T2, and the relay uplink (R-u) is allocated to the resource
block group defined by fi-equency Fl - time T2.
[0121]
In this manner, also with the allocation pattern 6, as with the allocation
pattern 5, the relay link and the access link are separated by fi-equency. Accordingly,
the delay that occurs between the downlink of the relay link and the downlink of the
access link can be reduced fi-om a per-slot basis to a per-OFDM-symbol basis.
Likewise, the delay that occurs between the uplink of the access link and the uplink
of the relay link can be reduced fi-om a per-slot basis to a per-OFDM-symbol basis.
[0122]
Specifically, the base station 10 transmits data to the relay device 30 via the
relay downlink in a resource block included in the resource block group defined by
fi-equency Fl - time Tl. Then, the relay device 30 performs, using a resource block
included in the resource block group defined by frequency F2 - time Tl, decoding,
buffering, encoding, and transmission to the mobile terminal 20 via the access
downlink of data received via the relay downlink, with the amount of delay on a per-
29
OFDM-symbol basis from the reception. Additionally, the amount of delay may be
variable between one OFDM symbol to a plurality of OFDM symbols.
[0123]
Also, the mobile terminal 20 transmits data to the relay device 30 via the
access uplink in a resource block included in the resource block group defined by
frequency F2 - time T2. Then, the relay device 30 performs, using a resource block
included in the resource block group defined by frequency Fl - time T2, decoding,
buffering, encoding, and transmission to the base station 10 via the relay uplink of
data received via the access uplink, with the amount of delay on a per-OFDMsymbol
basis from the reception.
[0124]
As described, according to the allocation pattern 6, the relay link and the
access link are separated by frequency (FDD), and the uplink and the downlink are
separated by both time and frequency (TDD). Therefore, according to the
allocation pattern 6, the delay that occurs between the base station 10 and the mobile
terminal 20 can be reduced compared to the allocation patterns 1 to 4 where the relay
link and the access link are separated by time, while suppressing the interference
between each link.
[0125]
Furthermore, according to the allocation pattern 6, the direct downlink (D-d)
is allocated to the same resource block group defined by frequency Fl - time Tl as
the relay downlink (R-d) and the same resource block group defined by frequency F2
- time Tl as the access downlink (A-d).
[0126]
Similarly, the direct uplink (D-u) is allocated to the same resource block
group defined by frequency Fl - time T2 as the relay uplink (R-u) and the same
resource block group defined by frequency F2 - time T2 as the access uplink (A-u).
[0127]
By performing link allocation according to the allocation pattern 6 in this
manner, a resource block group can be shared between the relay link or the access
link and the direct link.
30
[0128]
(Allocation Pattern 7)
Fig. 14 is an explanatory diagram showing an allocation pattern 7 for each
link. As shown in Fig. 14, according to the allocation pattern 7, the relay downlink
(R-d) is allocated to the resource block group defined by fi-equency Fl - time Tl, the
access downlink (A-d) is allocated to the resource block group defined by fi-equency
F2 - time Tl, the relay uplink (R-u) is allocated to the resource block group defined
by fi-equency F3 - time Tl, and the access uplink (A-u) is allocated to the resource
block group defined by fi-equency F4 - time Tl.
[0129]
In this maimer, according to the allocation pattern 7, the relay link and the
access link are separated by fi*equency, and the uplink and the downlink are also
separated by fi-equency. Therefore, according to the allocation pattern 7, as with the
allocation patterns 5 and 6, the delay at the relay device 30 can be reduced to a per-
OFDM-symbol basis, and also, to use one of the uplink and the downlink, it is not
necessary to wait for the completion of the other.
[0130]
Specifically, the base station 10 transmits data to the relay device 30 via the
relay downlink in a resource block included in the resource block group defined by
fi-equency Fl - time Tl. Then, the relay device 30 performs, using a resource block
included in the resource block group defined by fi-equency F2 - time Tl, decoding,
buffering, encoding, and transmission to the mobile terminal 20 via the access
downlink of data received via the relay downlink, with the amount of delay on a per-
OFDM-symbol basis fi-om the reception. Additionally, the amount of delay may be
variable between one OFDM symbol to a plurality of OFDM symbols.
[0131]
Also, the mobile terminal 20 transmits data to the relay device 30 via the
access uplink in a resource block included in the resoiirce block group defined by
fi-equency F4 - time Tl. Then, the relay device 30 performs, using a resource block
included in the resource block group defined by frequency F3 - time Tl, decoding,
buffering, encoding, and transmission to the base station 10 via the relay uplink of
31
data received via the access uplink, with the amount of delay on a per-OFDMsymbol
basis from the reception.
[0132]
Furthermore, according to the allocation pattern 7, the direct downlink (D-d)
is allocated to the same resource block group defined by frequency Fl - time Tl as
the relay downlink (R-d) and the same resource block group defined by frequency F2
- time Tl as the access downlink (A-d).
[0133]
Similarly, the direct uplink (D-u) is allocated to the same resource block
group defined by frequency F3 - time Tl as the relay uplink and the same resource
block group defined by frequency F4 - time Tl as the access uplink (A-u).
[0134]
By performing link allocation according to the allocation pattern 7 in this
manner, a resource block group can be shared between the relay link or the access
link and the direct link.
[0135]
(Allocation Pattern 8)
Fig. 15 is an explanatory diagram showing an allocation pattern 8 for each
link. As shown in Fig. 15, according to the allocation pattern 8, the relay downlink
(R-d) is allocated to the resource block group defined by frequency Fl - time Tl, the
access downlink (A-d) is allocated to the resource block group defined by frequency
Fl - time T2, the relay uplink (R-u) is allocated to the resource block group defined
by frequency Fl - time T3, and the access uplink (A-u) is allocated to the resource
block group defined by frequency Fl - time T4.
[0136]
In this manner, according to the allocation pattern 8, the relay link and the
access link are separated by time, and the uplink and the downlink are also separated
by time. Therefore, according to the allocation pattem 8, the number of frequencies
to be used is small, but the delay characteristics are deteriorated compared to other
allocation patterns.
[0137]
32
Specifically, according to the allocation pattern 8, the base station 10
transmits data to the relay device 30 via the relay downlink in a resource block
included in the resource block group defined by fi-equency Fl - time Tl. Then, the
relay device 30 receives the data transmitted via the relay downlink, holds it in the
buffer 338 as relay data, and then transmits the relay data to the mobile terminal 20
via the access downlink in a resource block included in the resource block group
defined by frequency Fl - time T2.
[0138]
Also, the mobile terminal 20 transmits data to the relay device 30 via the
access uplink in a resource block included in the resource block group defined by
fi"equency Fl - time T4. Then, the relay device 30 receives the data transmitted via
the access uplink, holds it in the buffer 338 as relay data, and then transmits the relay
data to the base station 10 via the relay uplink in a resource block included in the
resource block group defined by fi-equency Fl - time T3.
[0139]
Furthermore, according to the allocation pattern 8, the direct downlink (D-d)
is allocated to the same resource block group defined by frequency Fl - time Tl as
the relay downlink (R-d) and the same resource block group defined by fi-equency Fl
- time T2 as the access downlink (A-d).
[0140]
Similarly, the direct uplink (D-u) is allocated to the same resource block
group defined by frequency Fl - time T3 as the relay uplink (R-u) and the same
resource block group defined by frequency Fl - time T4 as the access uplink (A-u).
[0141]
By performing link allocation according to the allocation pattern 8 in this
manner, a resource block group can be shared between the relay link or the access
link and the direct link.
[0142]
<5. Operation of Base Station>
In the foregoing, the configuration of the base station 10 according to the
present embodiment has been described. Next, the flow of link allocation by the
33
base station 10 will be described with reference to Fig. 16 as the operation of the
base station 10.
[0143]
Fig. 16 is a flow chart showing the flow of link allocation by the base
station 10. First, the scheduler 156 of the base station 10 selects a resource block
group to which the direct link will be allocated (S404). Next, the scheduler 156
decides whether the selected resource block group is used for the access link or the
relay link (S408).
[0144]
Then, in the case the selected resource block group is used for the relay link
and further for the relay downlink (S412), the scheduler 156 allocates the direct
downlink to the selected resource block group (S416). On the other hand, in the
case the selected resource block group is used for the relay link and further for the
relay uplink (S412), the scheduler 156 allocates the direct uplink to the selected
resource block group (S420),
[0145]
Furthermore, in the case the selected resource block group is used for the
access link and further for the access downlink (S424), the scheduler 156 allocates
the direct downlink to the selected resource block group (S428). On the other hand,
in the case the selected resource block group is used for the access link and further
for the access uplink (S424), the scheduler 156 allocates the direct uplink to the
selected resource block group (S432).
[0146]
<6. Suniniary>
As described above, the scheduler 156 of the base station 10 according to
the present embodiment allocates the direct uplink to the resource block included in
the same resource block group as the relay uplink or the access uplink. Similarly,
the scheduler 156 allocates the direct downlink to the resource block included in the
same resource block group as the relay downlink or the access downlink.
According to such a configuration, a resource block group can be shared between the
relay link or the access link and the direct link.
34
[0147]
The preferred embodiments of the present invention have been described
above with reference to the accompanying drawings, whilst the present invention is
not limited to the above examples, of course. A person skilled in the art may find
various alternations and modifications within the scope of the appended claims, and
it should be understood that they will naturally come imder the technical scope of the
present invention.
[0148]
For example, the steps of the processing of the base station 10 of the present
specification do not necessarily have to be processed chronologically according to
the order described as the sequence chart. For example, the steps of the processing
of the base station 10 may be processed according to an order different fi-om the
order shown as the flow chart or may be processed in parallel.

CLAIMS
Claim 1
A base station comprising:
a communication imit for commimicating with a mobile terminal via a relay
link between the base station and a relay device and an access link between the relay
device and the mobile terminal, or a direct link between the base station and the
mobile terminal; and
an allocation unit for allocating an uplink and a downlink of each of the
relay link, the access link, and the direct link to resource blocks included in any of a
plurality of resource block groups,
wherein the allocation unit
allocates the downlink of the relay link or the access link and the
downlink of the direct link to a resource block included in a same resource block
group, and
allocates the uplink of the relay link or the access link and the
uplink of the direct link to a resource block included in a same resource block group.
Claim 2
The base station according to claim 1,
wherein a first resource block group for the downlink of the relay link, a
second resource block group for the downlink of the access link, a third resoiirce
block group for the uplink of the access link, and a fourth resovirce block group for
the uplink of the relay link are different in at least time or frequency.
Claims
The base station according to claim 2,
wherein the first resource block group is same in frequency but different in
time from the second resource block group, and is same in time but different in
frequency from the third resource block group, and
wherein the fourth resource block group is same in time but different in
frequency from the second resource block group, and is same in frequency but
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different in time from the third resource block group.
Claim 4
The base station according to claim 2,
wherein the first resource block group is same in frequency but different in
time from the second resource block group, and is same in time but different in
frequency from the fourth resource block group, and
wherein the third resource block group is same in time but different in
frequency from the second resource block group, and is same in frequency but
different in time from the fo\irth resource block group.
Claims
The base station according to claim 2,
wherein the first resource block group is same in frequency but different in
time from the fourth resource block group, and is same in time but different in
frequency from the third resource block group, and
wherein the second resource block group is same in time but different in
frequency from the fourth resource block group, and is same in frequency but
different in time from the third resource block group.
Claim 6
The base station according to claim 2,
wherein the first resource block group is same in frequency but different in
time from the third resource block group, and is same in time but different in
frequency from the fourth resource block group, and
wherein the second resource block group is same in time but different in
frequency from the third resource block group, and is same in frequency but different
in time from the fourth resource block group.
Claim?
The base station according to claim 2,
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wherein the first resource block group is same in fi-equency but different in
time from the third resource block group, and is same in time but dififerent in
frequency from the second resource block group, and
wherein the fourth resource block group is same in time but different in
frequency from the third resource block group, and is same in frequency but different
in time from the second resource block group.
Claim 8
The base station according to claim 2,
wherein the first resource block group is same in frequency but different in
time from the fourth resource block group, and is same in time but different in
frequency from the second resource block group, and
wherein the third resource block group is same in time but different in
frequency from the fourth resource block group, and is same in frequency but
dififerent in time from the second resource block group.
Claim 9
The base station according to claim 2,
wherein the first resource block group, the second resource block group, the
third resource block group, and the fourth resource block group are same in time but
different in frequency.
Claim 10
The base station according to claim 2,
wherein the first resource block group, the second resource block group, the
third resource block group, and the fourth resource block group are same in
frequency but dififerent in time.
Claim 11
A communication system comprising:
a mobile terminal;
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a relay device; and
a base station Locluding
a communication unit for communicating with the mobile terminal
via a relay link between the base station and the relay device and an access link
between the relay device and the mobile terminal, or a direct link between the base
station and the mobile terminal, and
an allocation unit for allocating an uplink and a downlink of each
of the relay link, the access link, and the direct link to resource blocks included in
any of a plurality of resource block groups,
wherein the allocation imit
allocates the downlink of the relay link or the access link
and the downlink of the direct link to a resoiirce block included in a same resource
block group, and
allocates the uplink of the relay link or the access link and
the uplink of the direct link to a resource block included in a same resource block
group.
Claim 12
A mobile terminal,
wherein the mobile terminal communicates with a base station using a
resource block allocated by an allocation imit, the base station including a
communication unit for communicating with the mobile terminal via a relay link
between the base station and a relay device and an access link between the relay
device and the mobile terminal, or a direct link between the base station and the
mobile terminal, and the allocation unit for allocating an uplink and a downlink of
each of the relay link, the access link, and the direct link to resource blocks included
in any of a plurality of resource block groups, where the allocation unit allocates the
downlink of the relay link or the access link and the downlink of the direct link to a
resource block included in a same resource block group, and allocates the uplink of
the relay link or the access link and the uplink of the direct link to a resource block
included in a same resource block group.
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Claim 13
A relay device,
wherein the relay device relays communication between a base station and a
mobile terminal using a resource block allocated by an allocation unit, the base
station including a communication unit for communicating with the mobile terminal
via a relay link between the base station and the relay device and an access link
between the relay device and the mobile terminal, or a direct link between the base
station and the mobile terminal, and the allocation unit for allocating an uplink and a
downlink of each of the relay link, the access link, and the direct link to resource
blocks included in any of a plurality of resource block groups, where the allocation
unit allocates the downlink of the relay link or the access link and the downlink of
the direct link to a resource block included in a same resource block group, and
allocates the uplink of the relay link or the access link and the uplink of the direct
link to a resource block included in a same resource block group.
Dated this 16/01/2012