1. A wireless communication system, comprising: a plurality of wireless devices configured to communicate with each other; each of the wireless devices including: a transmission unit configured to transmit a carrier of a fixed strength with polarization waves thereof rotated to a different one of the wireless devices using two antennae spatially orthogonal to each other; a reception unit configured to receive a carrier transmitted from the transmission unit of the different wireless device; and a timing detection unit configured to detect a timing at which the polarization waves of the carrier received by the reception unit within a period of rotation indicates a maximum strength; the transmission unit performing transmission or reception of a specific information signal using the carrier based on the timing detected by the timing detection unit.

2. The wireless communication system according to claim 1, wherein the transmission units of the plurality of wireless devices have a common cyclic code and superimpose the cyclic code to the information signal 76 using the timing detected by the timing detection unit as a reference point.

3. The wireless communication system according to claim 1, wherein the transmission units of the plurality of wireless devices have a plurality of cyclic codes different from each other that are common to those of the other ones of the plurality of wireless devices and performs switching of the plurality of different cyclic codes at a timing based on the timing detected by the timing detection unit so as to superimpose one of the cyclic codes to the information signal.

4. The wireless communication system according to claim 1, wherein the transmission units of the plurality of wireless devices have a common synchronization code and superimpose the synchronization code to the information signal at a timing different from the timing at which the cyclic code is used such that synchronism of a period of rotation of polarization waves of the carrier is established between the plurality of radio waves.

5. The wireless communication system according to claim 2, wherein each of the wireless devices further includes a timer configured to store the timing detected by the timing detection unit, and the transmission unit superimposes the cyclic code to the information signal at a timing based on the 77 timing stored in the timer and a period of rotation of polarization waves of the carrier.

6. The wireless communication system according to claim 1, wherein each of the wireless devices further includes a log memory configured to store information of the timing detected by the timing detection unit in a time series, and the transmission unit detects a situation variation of a wireless environment surrounding the wireless device based on information of the timing stored in the log memory.

7. The wireless communication system according to claim 1, wherein at least one pair of ones of the plurality of wireless devices are different from each other in direction of rotation of polarization waves of the carrier.

8. A wireless communication system, comprising: a plurality of wireless devices configured to communicate with each other and including a rotational polarization wireless device configured to transmit rotational polarization waves and a fixed polarization wireless device configured to transmit linear polarization waves; the rotational polarization wireless device including a first transmission unit configured to transmit a carrier of a fixed strength with 78 polarization waves thereof rotated to the fixed polarization wireless device using two antennae spatially orthogonal to each other, a first reception unit configured to receive a carrier transmitted from the second transmission unit of the fixed polarization wireless device, and a first timing detection unit configured to detect a timing at which the polarization waves of the carrier received by the first reception unit indicates a maximum strength, the first transmission unit performing transmission or reception of a specific information signal that uses the carrier based on the timing detected by the first timing detection unit; the fixed polarization wireless device including a second transmission unit configured to transmit linear polarization waves of a carrier of a fixed strength to the rotational polarization wireless device using one antenna, a second reception unit configured to receive a carrier transmitted from the first transmission unit of the rotational polarization wireless device using one antenna, and a second timing detection unit configured to detect a timing at which the polarization waves of the carrier received by the second reception unit indicate a maximum intensity within a period of rotation of the polarization waves of the carrier received by the second reception unit, the second transmission unit performing transmission or reception of a specific information signal that uses 79 the carrier based on the timing detected by the second timing detection unit.

9. The wireless communication system according to claim 8, wherein the first transmission unit of the rotational polarization wireless device and the second transmission unit of the fixed polarization wireless device have a common cyclic code and superimpose the cyclic code to the information signal using the timing detected by the first or second timing detection unit as a reference point.

10. The wireless communication system according to claim 1, wherein the transmission unit includes a cosine wave generation circuit and a sine wave generation unit configured to generate a cosine wave and a sine wave of a first frequency, respectively, and another cosine wave generation circuit and another sine wave generation circuit configured to generate a cosine wave and a sine wave of a second frequency different from the first frequency, respectively, and the polarization waves of the carrier are rotated by a frequency equal to one half a difference between the first frequency and the second frequency.

11. An elevator controlling system, comprising: an elevator cab configured to move up and down in the inside of a building; and 80 the wireless devices of the wireless communication system according to claim 1 each disposed at corresponding one end and the other end of a range of movement of the elevator cab in the inside of the building.

12. A substation controlling system, comprising: a plurality of substation machines disposed in electric substation equipment; at least one base station apparatus configured to control the plurality of substation machines, the number of the base station apparatus being smaller than the number of the substation machines; and the wireless devices of the wireless communication system according to claim 1 each disposed at corresponding one of the plurality of substation machines and the base station apparatus.

TITLE OF THE INVENTION
WIRELESS COMMUNICATION SYSTEM
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001]
The present invention relates to a wireless
communication system that transmits and receives
information using polarization waves whose polarization
angle varies.
2. Description of the Related Art
[0002]
Toward the realization of sustainable
development of society, high-efficiency operation of
social infrastructure systems for producing and
distributing, for example, energy, water, gas,
petroleum and so forth is important. To this end, highfrequency
operation of apparatus configuring the
systems is required. In order to implement highefficiency
operation of apparatus configuring a system,
a technology is considered promising that collects and
analyzes a great amount of data obtained from a large
number of sensors disposed in the individual apparatus
configuring the system to estimate and predict an
operational status and control information obtained on
the basis of a result of the estimation is transmitted
to the individual apparatus. Thus, a monitoring and
controlling network for the technology is required.
3
[0003]
In the monitoring and controlling network, a
very great number of transmission paths are required
for collecting data from the large number of sensors
and transmitting control information to the individual
apparatus. Therefore, a network configuration which
uses a wireless communication technology suitable for a
network having a great number of transmission paths is
demanded.
[0004]
Sensors disposed in an apparatus configuring a
social infrastructure system and actuators for
controlling the apparatus act themselves as
electromagnetic wave scattering bodies. Therefore, in a
wireless network that uses electromagnetic waves as a
communication medium, it cannot be expected for a
wireless device configuring the network to communicate
in a line-of-sight state, and the network is operated
in a special state in which it uses a non-line-of-sight
wave for which a multiple reflection wave after
reflection by the apparatus is used. As one of
technologies for use in such a situation as just
described, for example, a technology for implementing
wireless communication of high reliability by a
transmission antenna and a reception antenna of a small
size under an environment in which interference by
multipath waves occurs is disclosed, for example, in
JP-2015-039218-A. The technology relates to a
4
polarization angle division diversity wireless
transmitter that includes modulation means for
modulating an information signal of a first frequency
with a second frequency and outputting a resulting
first modulation signal, and electromagnetic wave
transmission means for transmitting the first
modulation signal in the form of two polarization waves
independent of each other and superimposing a third
frequency to the polarization waves.
SUMMARY OF THE INVENTION
[0006]
Since a social infrastructure system plays an
important role to provide a lifeline to the society, it
is necessary to strictly restrict intervention in the
system by an outsider, and the security in operation of
the network is very important. Generally, in wireless
communication, a transmission path is an open space,
and therefore, it is very difficult to specify a
specific transmission path in comparison with wire
communication. However, in the proximity of the system,
even an outsider can easily acquire energy of wireless
communication. Therefore, the possibility of discovery
of or intervention in the transmission path by an
outsider cannot be denied, and this is a technical
subject to be solved from the point of view of the
security.
[0007]
5
It is an object of the present invention to
provide a wireless communication system that can
conceal transmission information by wireless
communication against an outsider.
[0008]
To attain the object described above, according
to the present invention, there is provided a wireless
communication system including a plurality of wireless
devices configured to communicate with each other, each
of the wireless devices including a transmission unit
configured to transmit a carrier of a fixed strength
with polarization waves thereof rotated to a different
one of the wireless devices using two antennae
spatially orthogonal to each other, a reception unit
configured to receive a carrier transmitted from the
transmission unit of the different wireless device, and
a timing detection unit configured to detect a timing
at which the polarization waves of the carrier received
by the reception unit within a period of rotation
indicates a maximum strength, the transmission unit
performing transmission or reception of a specific
information signal using the carrier based on the
timing detected by the timing detection unit.
[0009]
With the wireless communication system,
transmission information by wireless communication can
be concealed against an outsider, and high efficiency
6
operation of a social infrastructure system can be
implemented with high security.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010]
FIG. 1 is a block diagram schematically
depicting a wireless communication system according to
a first embodiment;
FIG. 2 is a block diagram schematically
depicting a wireless communication system according to
a second embodiment;
FIG. 3 is a block diagram schematically
depicting a wireless communication system according to
a third embodiment;
FIG. 4 is a block diagram schematically
depicting a wireless communication system according to
a fourth embodiment;
FIG. 5 is a block diagram schematically
depicting a wireless communication system according to
a fifth embodiment;
FIG. 6 is a block diagram schematically
depicting a wireless communication system according to
a sixth embodiment;
FIG. 7 is a block diagram schematically
depicting a wireless communication system according to
a seventh embodiment;
7
FIG. 8 is a block diagram schematically
depicting a wireless communication system according to
an eighth embodiment;
FIG. 9 is a block diagram schematically
depicting a wireless communication system according to
a ninth embodiment;
FIG. 10 is a block diagram schematically
depicting a wireless communication system according to
a tenth embodiment;
FIG. 11 is a block diagram schematically
depicting a wireless communication system according to
an eleventh embodiment;
FIG. 12 is a block diagram schematically
depicting a wireless communication system according to
a twelfth embodiment;
FIG. 13 is a block diagram schematically
depicting a wireless communication system according to
a thirteenth embodiment; and
FIG. 14 is an explanatory view illustrating
operation of the wireless communication system
according to the first embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011]
In the following, embodiments of the present
invention are described in detail with reference to
FIGS. 1 to 14.
[0012]
8
First Embodiment
A first embodiment of the present invention is
described in detail with reference to FIGS. 1 and 14.
[0013]
FIG. 1 is a block diagram schematically
depicting a wireless communication system according to
the first embodiment.
[0014]
FIG. 1 exemplifies a set of wireless devices
extracted from a plurality of wireless devices which
configure the wireless communication system, namely,
exemplifies rotational polarization wireless devices
301 and 401. Referring to FIG. 1, the rotational
polarization wireless device 301 generally includes a
transmission system (transmission unit), a reception
system (reception unit) and a signal processing system.
The transmission system is configured from an
information signal generator 1, a cyclic code
generation circuit 2, a cosine rotation frequency
generation circuit 4, a sine rotation frequency
generation circuit 14, a carrier frequency generation
circuit 11, power amplifiers 9 and 19, transmission
antennae 10 and 20 and multipliers 3, 5, 8, 13, 15 and
18. The reception system is configured from reception
antennae 80 and 90, low noise amplifiers 81 and 91, a
local oscillation circuit 89, multipliers 82 and 92,
band-pass filters 83 and 93, buffer amplifiers 84 and
9
94 and delay devices 85 and 95. The signal processing
system includes a digital signal processing circuit 99.
[0015]
The information signal generator 1 generates an
information signal (specific information signal for
being transmitted to the other rotational polarization
wireless device 401, and branches the generated
information signal into two branched signals. The
cyclic code generation circuit 2 generates a cyclic
code on the basis of a control signal from the digital
signal processing circuit 99 and superimposes the
generated cyclic code to one of the information signals
outputted as two branch signals from the information
signal generator 1 through the multiplier 3 and to the
other of the information signals through the multiplier
13. The cosine rotation frequency generation circuit 4
and the sine rotation frequency generation circuit 14
generate signals having a relationship of a cosine wave
and a sine wave, respectively. The cosine rotation
frequency generation circuit 4 superimposes the
generated signal to one of the information signals
outputted as two branch signals from the information
signal generator 1 by the multiplier 5, and the sine
rotation frequency generation circuit 14 multiplies the
generated signal to the other of the information
signals outputted as two branch signals from the
information signal generator 1 by the multiplier 15.
The carrier frequency generation circuit 11 generates a
10
carrier signal to be used for transmission of an
information signal to the rotational polarization
wireless device 401 and multiplies the generated
carrier signal to the information signals outputted as
two branch signals from the information signal
generator 1 through the multipliers 8 and 18. The power
amplifiers 9 and 19 amplify the information signals
outputted as two branch signals from the information
signal generator 1 and send the amplified information
signals to the transmission antennae 10 and 20,
respectively. The two transmission antennae 10 and 20
are disposed so as to be spatially orthogonal to each
other, and the information signals sent through the
power amplifiers 9 and 19 (carrier signals to which the
information signals are superimposed) are radiated as
electromagnetic waves (radio waves) into the space from
the transmission antennae 10 and 20.
[0016]
The two reception antennae 80 and 90 are
disposed so as to be spatially orthogonal to each other
and simultaneously receive electromagnetic waves
(reception electric fields) radiated from the other
rotational polarization wireless device 401. The
electromagnetic waves received by the reception
antennae 80 and 90 (information signals superimposed to
the carrier signal) are amplified by the low noise
amplifiers 81 and 91, respectively. The local
oscillation circuit 89 generates a signal of a
11
frequency same as that of the carrier signal,
multiplies the generated signal to the information
signals amplified by the low noise amplifiers 81 and 91
through the multipliers 82 and 92 and then send
resulting signals to the band-pass filters 83 and 93,
respectively. The information signals having passed the
band-pass filters 83 and 93 are amplified by the buffer
amplifiers 84 and 94 and sent to the delay devices 85
and 95, respectively. The delay devices 85 and 95 are
each configured from a plurality of (for example, n)
delay devices 85a, 85b, ..., 85n, or 95a, 95b, ..., 95n
connected in cascade. The inputted information signals
are successively delayed by the delay devices 85a,
85b, ..., 85n, and 95a, 95b, ..., 95n and inputted to
the digital signal processing circuit 99.
[0017]
The digital signal processing circuit 99
controls operation of the entire rotational
polarization wireless device 301. The digital signal
processing circuit 99 includes an information signal
processing function unit which processes information
signals inputted through the delay devices 85 and 95,
and a timing detection function unit (timing detection
unit) for detecting a timing at which the strength of a
polarization wave of each of the information signals
exhibits a maximum value within a period of rotation.
If the timing detection function unit of the digital
signal processing circuit 99 detects a timing at which
12
the strength of a reception signal exhibits a maximum
value, then it sends a control signal for generating a
cyclic code to be superimposed to the information
signal from the information signal generator 1 to the
cyclic code generation circuit 2.
[0018]
Here, the information signal generator 1, cyclic
code generation circuit 2, cosine rotation frequency
generation circuit 4, sine rotation frequency
generation circuit 14, multipliers 3, 5, 13 and 15,
delay devices 85 and 95 and digital signal processing
circuit 99 configure a digital rotational polarization
wave transmission and reception module 101.
[0019]
Also the rotational polarization wireless device
401 paired with the rotational polarization wireless
device 301 has a configuration similar to that of the
rotational polarization wireless device 301. In
particular, the rotational polarization wireless device
401 generally includes a transmission system
(transmission unit), a reception system (reception
unit) and a signal processing system. The transmission
system is configured from an information signal
generator 51, a cyclic code generation circuit 52, a
cosine rotation frequency generation circuit 54, a sine
rotation frequency generation circuit 64, a carrier
frequency generation circuit 61, power amplifiers 59
and 69, transmission antennae 60 and 70, and
13
multipliers 53, 55, 58, 63, 65 and 68. The reception
system is configured from reception antennae 30 and 40,
low noise amplifiers 31 and 41, a local oscillation
circuit 39, multipliers 32 and 42, band-pass filters 33
and 43, buffer amplifiers 34 and 44 and delay devices
35 and 45. The signal processing system includes a
digital signal processing circuit 49.
[0020]
The information signal generator 51 generates an
information signal (specific information signal for
being transmitted to the rotational polarization
wireless device 301, and branches the generated
information signal into two branched signals. The
cyclic code generation circuit 52 generates a cyclic
code on the basis of a control signal from the digital
signal processing circuit 49 and superimposes the
generated cyclic code to one of the information signals
outputted as two branch signals from the information
signal generator 51 through the multiplier 53 and to
the other of the information signals through the
multiplier 63. The cosine rotation frequency generation
circuit 54 and the sine rotation frequency generation
circuit 64 generate signals having a relationship of a
cosine wave and a sine wave, respectively. The cosine
rotation frequency generation circuit 54 superimposes
the generated signal to one of the information signals
outputted as two branch signals from the information
signal generator 51 by the multiplier 55, and the sine
14
rotation frequency generation circuit 64 multiplies the
generated signal to the other of the information
signals outputted as two branch signals from the
information signal generator 51 by the multiplier 65.
The carrier frequency generation circuit 61 generates a
carrier signal to be used for transmission of an
information signal to the rotational polarization
wireless device 301 and multiplies the generated
carrier signal to the information signals outputted as
two branch signals from the information signal
generator 51 through the multipliers 58 and 68. The
power amplifiers 59 and 69 amplify the information
signals outputted as two branch signals from the
information signal generator 51 and send the amplified
information signals to the transmission antennae 60 and
70, respectively. The two transmission antennae 60 and
70 are disposed so as to be spatially orthogonal to
each other, and the information signals sent through
the power amplifiers 59 and 69 (carrier signals to
which the information signals are superimposed) are
radiated as electromagnetic waves (radio waves) into
the space from the transmission antennae 60 and 70.
[0021]
The two reception antennae 30 and 40 are
disposed so as to be spatially orthogonal to each other
and simultaneously receive electromagnetic waves
(reception electric fields) radiated from the other
rotational polarization wireless device 301. The
15
electromagnetic waves received by the reception
antennae 30 and 40 (information signals superimposed to
the carrier signal) are amplified by the low noise
amplifiers 31 and 41, respectively. The local
oscillation circuit 39 generates a signal of a
frequency same as that of the carrier signal,
multiplies the generated signal to the information
signals amplified by the low noise amplifiers 31 and 41
through the multipliers 32 and 42 and then send
resulting signals to the band-pass filters 33 and 43,
respectively. The information signals having passed the
band-pass filters 33 and 43 are amplified by the buffer
amplifiers 34 and 44 and sent to the delay devices 35
and 45, respectively. The delay devices 35 and 45 are
each configured from a plurality of (for example, n)
delay devices 35a, 35b, ..., 35n, or 45a, 45b, ..., 45n
connected in cascade. The inputted information signals
are successively delayed by the delay devices 35a,
35b, ..., 35n, or 45a, 45b, ..., 45n and inputted to
the digital signal processing circuit 49.
[0022]
The digital signal processing circuit 49
controls operation of the entire rotational
polarization wireless device 401. The digital signal
processing circuit 49 includes an information signal
processing function unit which processes information
signals inputted through the delay devices 35 and 45,
and a timing detection function unit (timing detection
16
unit) for detecting a timing at which the strength of a
polarization wave of each of the information signals
exhibits a maximum value within a period of rotation.
If the timing detection function unit of the digital
signal processing circuit 49 detects a timing at which
the strength of a reception signal exhibits a maximum
value, then it sends a control signal for generating a
cyclic code to be superimposed to the information
signal from the information signal generator 51 to the
cyclic code generation circuit 52.
[0023]
Here, the information signal generator 51,
cyclic code generation circuit 52, cosine rotation
frequency generation circuit 54, sine rotation
frequency generation circuit 64, multipliers 53, 55, 63
and 65, delay devices 35 and 45 and digital signal
processing circuit 49 configure a digital rotational
polarization wave transmission and reception module
101a.
[0024]
The present embodiment configured in such a
manner as described above is described in more detail
below.
[0025]
Radio waves radiated from the transmission
antennae 10 and 20 of the rotational polarization
wireless device 301 and the transmission antennae 60
and 70 of the rotational polarization wireless device
17
401 are rotational polarization waves whose
polarization plane rotates, and the carrier frequency
and the cosine-sine rotational frequency are set such
that the polarization waves rotate at a frequency
sufficiently low in comparison with the frequency of
the carrier. Further, the rotational polarization
wireless devices 301 and 401 simultaneously communicate
polarization waves changing the rotational polarization
wave frequencies periodically. By setting the frequency
of the rotational polarization waves sufficiently low,
the transmission and reception timings of the
rotational polarization wireless device 301 and the
transmission and reception timings of the rotational
polarization wireless device 401 can be made
substantially same as each other. It is to be noted
that preferably the rotational frequency of the
rotational polarization waves is set such that the
wavelength is sufficiently long (for example, more than
five times) in comparison with the disposition distance
between electromagnetic wave scattering bodies such as
furniture a plurality of which are supposed to exist
between the rotational polarization wireless devices
301 and 401.
[0026]
A plurality of incoming waves which arrive at
the rotational polarization wireless device 401 through
a plurality of propagation paths from the rotational
polarization wireless device 301 can be regarded, in
18
regard to rotation of the polarization plane, as
aligned in phase. Therefore, the incoming waves are
regarded as a single rotational polarization wave which
has a unique polarization angle difference from the
transmission polarized waves and having a same
rotational polarization wave frequency (one rotational
polarization wave formed from the sum total of a
plurality of polarization vectors). Since the
rotational polarization wireless device 401 can know a
strength distribution of polarized waves of a reception
electric field by the reception antennae 30 and 40
which are spatially orthogonally disposed, if
transmission polarization waves used by the rotational
polarization wireless device 301 can be known, then it
is possible to obtain a unique polarization angle
difference arising in transmission and reception. The
same is true for a plurality of incoming waves which
arrive at the rotational polarization wireless device
301 through a plurality of propagation paths from the
rotational polarization wireless device 401.
[0027]
The unique polarization angle difference arising
in transmission and reception sides between the pair of
rotational polarization wireless devices 301 and 401 is
automatically shared simultaneously between the
rotational polarization wireless devices 301 and 401
which are communicating simultaneously from symmetry
and relativity of communication which uses
19
electromagnetic waves. Accordingly, even if radio wave
environments surrounding the rotational polarization
wireless devices 301 and 401 vary, they can
automatically share a unique polarization angle
difference following the variation.
[0028]
Further, the unique polarization angle
difference arising in transmission and reception
between the paired rotational polarization wireless
devices 301 and 401 is different from the unique
polarization angle difference in a different rotational
polarization wireless device pair (except a special
case). In particular, even in a case in which
pluralities of rotational polarization wireless devices
are disposed, transmission paths in which the
polarization angle difference is different among
different rotational polarization wireless device pairs
are virtually formed. Besides, the features of the
propagation paths (polarization angle differences in
transmission and reception) are concealed not only to
the outside of the wireless communication system but
also to the other wireless device pairs in the wireless
communication system.
[0029]
Further, outputs of the cyclic code generation
circuits 2 and 52 are superimposed to outputs of the
information signal generators 1 and 51 transmitted from
the rotational polarization wireless devices 301 and
20
401, respectively. The rotational polarization wireless
devices 301 and 401 paired with each other share a same
cyclic code. One (transmission side) of the paired
rotational polarization wireless devices 301 and 401
superimposes the shared cyclic code using a unique
timing within a period of rotational polarization
corresponding to the unique polarization angle
difference (for example, a timing at which the signal
strength of the reception signal exhibits a maximum
value) as a start point while the other (reception
side) of the paired rotational polarization wireless
devices 301 and 401 takes a sliding correlation with
the cyclic code of the reception signal and can know
transmission polarization waves used by the paired
rotational polarization wireless devices 301 and 401
from a timing at which the sliding correlation exhibits
a maximum value.
[0030]
Further, the cyclic code generation circuits 2
and 52 start generation of a cyclic code on the basis
of control signals from digital signal processing
circuits 99 and 49 at a unique timing within a period
of rotational polarization corresponding to a unique
polarization angle difference between the rotational
polarization wireless devices 301 and 401 paired with
each other, and the rotational polarization wireless
devices 301 and 401 can correctly demodulate a signal
transmitted from one to the other of the wireless
21
devices by superimposing the cyclic code to the
reception signal. Such operation is performed by the
digital signal processing circuits 99 and 49 which
control operation of the rotational polarization
wireless devices 301 and 401, respectively. At a place
other than the paired rotational polarization wireless
devices 301 and 401, the unique polarization angle
difference used by the paired rotational polarization
wireless devices 301 and 401 cannot be obtained, and
therefore, restoration of the transmission signal using
the cyclic code cannot be performed.
[0031]
FIG. 14 is an explanatory view of operation of
the wireless communication system according to the
present embodiment.
[0032]
In particular, FIG. 14 depicts an example of a
configuration of a wireless communication system in
which, using rotational polarization waves, information
is concealed and transmitted using a unique
polarization angle shift. Further, FIG. 14 illustrates
correspondence between an information signal generated
by an information generation circuit (information
signal generator) and a cyclic code generated by a
cyclic code generation circuit.
[0033]
Referring to FIG. 14, a cyclic code generated by
the cyclic code generation circuit of each rotational
22
polarization wireless device indicates a low noise
property. In particular, since an information signal to
which a cyclic code is superimposed indicates a false
noise property, it is recognized as noise by an
outsider. Accordingly, the substance of the information
in the information signal is concealed.
[0034]
Further, since a pair of rotational polarization
wireless devices communicate simultaneously using
rotational polarization waves having different rotation
directions, physical interference does not occur
between the rotational polarization waves and
bidirectional simultaneous communication by the paired
rotational polarization wireless devices can be
achieved.
[0035]
Advantageous effects of the present invention
having such a configuration as described above are
described below.
[0036]
Since a social infrastructure system plays an
important role to provide a lifeline to the society, it
is necessary to strictly restrict intervention in the
system by an outsider, and the security in operation of
the network is very important. Generally, in wireless
communication, a transmission path is an open space,
and therefore, it is very difficult to specify a
specific transmission path in comparison with wire
23
communication. However, in the proximity of the system,
even an outsider can easily acquire energy of wireless
communication. Therefore, the possibility of discovery
of or intervention in the transmission path by an
outsider cannot be denied, and this is a technical
subject to be solved from the point of view of the
security.
[0037]
In contract, in the present embodiment, a
wireless devices which includes a transmission unit
configured to transmit a carrier of a fixed strength
with polarization waves thereof rotated to a different
one of the wireless devices using two antennae
spatially orthogonal to each other, a reception unit
configured to receive a carrier transmitted from the
transmission unit of the different wireless device, and
a timing detection unit configured to detect a timing
at which the polarization waves of the carrier received
by the reception unit within a period of rotation
indicates a maximum strength is configured such that
the transmission unit performs transmission or
reception of a specific information signal using the
carrier based on the timing detected by the timing
detection unit. Therefore, transmission information by
wireless communication can be concealed against an
outsider.
[0038]
24
Since electromagnetic waves are vector waves and
physical realities called polarization waves orthogonal
to the advancing direction indicate a unique variation
by reflection, polarization waves of same polarization
automatically radiated in a plurality of directions
from a certain wireless device are reflected uniquely
by a plurality of structures. Therefore, at a wireless
device on the reception side, radio waves subject to
unique variations of the polarization waves through a
plurality of propagation paths arrive.
[0039]
In communication between a pair of wireless
devices, the sum total of the polarization vectors is
unique between a pair of transmission and reception
points and varies temporally irregularly. Besides, the
information cannot be physically recognized except the
pair of transmission and reception points. Therefore,
the polarization angle between a transmission
polarization wave and a reception polarization wave is
a physical amount which cannot be recognized except a
specific pair of wireless devices (transmitter and
receiver). Further, in the present embodiment, since
the wireless communication system is configured so as
to conceal information to be used using the physical
amount on the basis of the knowledge that a pair of
specific wireless devices can simultaneously share an
irregular variation of the physical amount by the
transmission-reception symmetry, specification of a
25
transmission path for information transmission by an
outsider can be prevented and the substance of
information being transmitted can be concealed.
[0040]
Second Embodiment
A second embodiment of the present invention is
described in detail with reference to FIG. 2.
[0041]
In the present embodiment, a single reception
antenna is used commonly to the reception units of the
rotational polarization wireless devices paired with
each other in the first embodiment.
[0042]
FIG. 2 is a view schematically depicting a
wireless communication system according to the present
embodiment, In FIG. 2, like elements to those in the
first embodiment are denoted by like reference
characters, and overlapping description of them is
omitted herein.
[0043]
FIG. 2 exemplifies a set of wireless devices
extracted from a plurality of wireless devices which
configure the wireless communication system, namely,
exemplifies rotational polarization wireless devices
302 and 402. Referring to FIG. 2, the rotational
polarization wireless device 302 generally includes a
transmission system (transmission unit), a reception
system (reception unit) and a signal processing system.
26
The transmission system is configured from an
information signal generator 1, an cyclic code
generation circuit 2, a cosine rotation frequency
generation circuit 4, a sine rotation frequency
generation circuit 14, a carrier frequency generation
circuit 11, power amplifiers 9 and 19, transmission
antennae 10 and 20 and multipliers 3, 5, 8, 13, 15 and
18. The reception system is configured from a reception
antenna 80, a low noise amplifier 81, a local
oscillation circuit 89, a multiplier 82, a band-pass
filter 83, a buffer amplifier 84 and a delay device 85.
The signal processing system includes a digital signal
processing circuit 99. The information signal generator
1, cyclic code generation circuit 2, cosine rotation
frequency generation circuit 4, sine rotation frequency
generation circuit 14, multipliers 3, 5, 13 and 15,
delay device 85 and digital signal processing circuit
99 configure a digital rotational polarization wave
transmission and reception module 102.
[0044]
Also the rotational polarization wireless device
402 paired with the rotational polarization wireless
device 302 has a configuration similar to that of the
rotational polarization wireless device 302. In
particular, the rotational polarization wireless device
402 generally includes a transmission system
(transmission unit), a reception system (reception
unit) and a signal processing system. The transmission
27
system is configured from an information signal
generator 51, an cyclic code generation circuit 52, a
cosine rotation frequency generation circuit 54, a sine
rotation frequency generation circuit 64, a carrier
frequency generation circuit 61, power amplifiers 59
and 69, transmission antennae 60 and 70, and
multipliers 53, 55, 58, 63, 65 and 68. The reception
system is configured from a reception antenna 30, a low
noise amplifier 31, a local oscillation circuit 39, a
multiplier 32, band-pass filter 33, a buffer amplifier
34 and a delay device 35. The signal processing system
includes a digital signal processing circuit 49. The
information signal generator 51, cyclic code generation
circuit 52, cosine rotation frequency generation
circuit 54, sine rotation frequency generation circuit
64, multipliers 53, 55, 63 and 65, delay device 35 and
digital signal processing circuit 49 configure a
digital rotational polarization wave transmission and
reception module 102a.
[0045]
The configuration of the other part of the
wireless communication system is similar to that in the
first embodiment.
[0046]
Also with the present embodiment configured in
such a manner as described above, similar advantageous
effects to those of the first embodiment can be
achieved.
28
[0047]
Further, in the present embodiment, although the
reception system (reception unit) of the rotational
polarization wireless devices 302 and 402 requires at
least a period of time equivalent to one cycle of
rotational polarization waves in order to obtain a
timing which exhibits a maximum value of the reception
electric field strength, since the components of the
circuit configuration of the rotational polarization
wireless device 302 can be reduced significantly, the
fabrication cost for the rotational polarization
wireless devices for configuring the wireless
communication system can be reduced.
[0048]
Third Embodiment
A third embodiment of the present invention is
described in detail with reference to FIG. 3.
[0049]
The present embodiment is configured such that
one of a pair of rotational polarization wireless
devices in the first embodiment is configured as a
fixed polarization wireless device having no function
for transmitting and receiving a rotational
polarization wave.
[0050]
FIG. 3 is a view schematically depicting a
wireless communication system according to the present
embodiment, In FIG. 3, like elements to those in the
29
first embodiment are denoted by like reference
characters, and overlapping description of them is
omitted herein.
[0051]
FIG. 3 exemplifies a set of wireless devices
extracted from a plurality of wireless devices which
configure the wireless communication system, namely,
exemplifies a rotational polarization wireless device
301 and a fixed polarization wireless device 403.
Referring to FIG. 3, the rotational polarization
wireless device 301 generally includes a transmission
system (transmission unit), a reception system
(reception unit) and a signal processing system. The
transmission system is configured from an information
signal generator 1, an cyclic code generation circuit 2,
a cosine rotation frequency generation circuit 4, a
sine rotation frequency generation circuit 14, a
carrier frequency generation circuit 11, power
amplifiers 9 and 19, transmission antennae 10 and 20
and multipliers 3, 5, 8, 13, 15 and 18. The reception
system is configured from reception antennae 80 and 90,
low noise amplifiers 81 and 91, a local oscillation
circuit 89, multipliers 82 and 92, band-pass filters 83
and 93, buffer amplifiers 84 and 94 and delay devices
85 and 95. The signal processing system includes a
digital signal processing circuit 99. The information
signal generator 1, cyclic code generation circuit 2,
cosine rotation frequency generation circuit 4, sine
30
rotation frequency generation circuit 14, multipliers 3,
5, 13 and 15, delay devices 85 and 95 and digital
signal processing circuit 99 configure a digital
rotational polarization wave transmission and reception
module 101.
[0052]
The fixed polarization wireless device 403
paired with the rotational polarization wireless device
301 generally includes a transmission system
(transmission unit), a reception system (reception
unit) and a signal processing system. The transmission
system is configured from an information signal
generator 51, a cyclic code generation circuit 52, a
cosine rotation frequency generation circuit 54, a
carrier frequency generation circuit 61, a power
amplifier 59, a transmission antenna 60, and
multipliers 53, 55 and 58. The reception system is
configured from a reception antenna 30, a low noise
amplifier 31, a local oscillation circuit 39, a
multiplier 32, band-pass filter 33, a buffer amplifier
34 and a delay device 35. The signal processing system
includes a digital signal processing circuit 49. The
information signal generator 51, cyclic code generation
circuit 52, cosine rotation frequency generation
circuit 54, multipliers 53 and 55, delay device 35 and
digital signal processing circuit 49 configure a
digital rotational polarization wave transmission and
reception module 201.
31
[0053]
In the wireless communication system configured
in such a manner as described above, in the reception
unit of the fixed polarization wireless device 403,
radio waves (reception signal) received by the
reception antenna 30 are amplified by the low noise
amplifier 31 and then multiplied by an output of the
local oscillation circuit 39, which generates a signal
of a frequency equal to the frequency of the carrier,
by the multiplier 32. The reception signal after the
output of the local oscillation circuit 39 is
multiplied is inputted to the buffer amplifier 34
through the band-pass filter 33, and an output of the
buffer amplifier 34 is successively delayed by the
delay device 35 and then inputted to the digital signal
processing circuit 49.
[0054]
Meanwhile, in the transmission unit of the fixed
polarization wireless device 403, an output of the
cyclic code generation circuit 52 is superimposed to an
output of the information signal generator 51 by the
multiplier 53 and then is multiplied by an output of
the cosine rotation frequency generation circuit 54 by
the multiplier 55, whereafter it is multiplied by an
output of the carrier frequency generation circuit 61
by the multiplier 58. Then, a resulting signal is
amplified by the power amplifier 59 and radiated from
the transmission antenna 60 into the space.
32
[0055]
The fixed polarization wireless device 403
receives rotational polarization waves and receives a
control signal from the digital signal processing
circuit 49 at a timing at which a maximum reception
electric field strength is obtained and then starts
generation of a cyclic code of the cyclic code
generation circuit 52. An output of the information
signal generator 51 is superimposed to an output of the
cyclic code generation circuit 52 by the multiplier 53
and is multiplied by an output of the cosine rotation
frequency generation circuit 54 by the multiplier 55,
whereafter it is multiplied by an output of the carrier
frequency generation circuit 61 by the multiplier 58.
Then, a resulting signal is amplified by the power
amplifier 59 and radiated from the transmission antenna
60 into the space.
[0056]
In the rotational polarization wireless device
301, the digital signal processing circuit 99 takes
sliding correlation with the reception signal using the
cyclic code shared by the fixed polarization wireless
device 403 and extracts a timing at which the signal
strength indicates a maximum value. Then, the digital
signal processing circuit 99 recognizes a relative
position of the timing on the time axis to the timing
of the polarization rotation of the rotational
33
polarization waves used for transmission by the fixed
polarization wireless device 403.
[0057]
The configuration of the other part of the
wireless communication system is similar to that in the
first embodiment.
[0058]
Also with the present embodiment configured in
such a manner as described above, similar advantageous
effects to those of the first embodiment can be
achieved.
[0059]
Further, with the present embodiment, since a
pair of wireless devices (a rotational polarization
wireless device and a fixed polarization wireless
device) are different in operation from each other, the
symmetry in transmission and reception is not satisfied
between the wireless devices. Accordingly, it is
impossible in principle to obtain relative positions on
a time axis of timings of rotational polarization waves
transmitted simultaneously and timings of received
rotational polarization waves between the paired
wireless devices. However, it is possible to obtain
relative position on a time axis of rotational
polarization waves transmitted approximately as errors
given by differences in propagation delay between
transmission and reception and time transition relating
to a processing time period of the digital signal
34
processing circuit 99 and received rotational
propagation waves. Particularly, if the difference in
time transition with respect to the rotational
polarization waves is so small that it can be ignored,
then it is possible in practical use to obtain relative
positions on a time axis of timings of rotational
polarization waves to be transmitted and received
rotational polarization waves with a small error. In
other words, in the present embodiment, since the fixed
polarization wireless device 403 can be configured in a
much simplified configuration in comparison with the
rotational polarization wireless device 301, scaling
down of the component apparatus of the wireless
communication system and reduction of the cost for the
entire wireless communication system can be anticipated.
[0060]
Fourth Embodiment
A fourth embodiment of the present invention is
described in detail below with reference to FIG. 4.
[0061]
The present embodiment is configured such that
the paired rotational polarization wireless devices in
the first embodiment include a synchronization code
generation circuit in addition to the cyclic code
generation circuit.
[0062]
FIG. 4 is a view schematically depicting the
wireless communication system according to the present
35
embodiment. In FIG. 4, like elements to those in the
first embodiment are denoted by like reference
characters, and overlapping description of them is
omitted herein.
[0063]
FIG. 4 exemplifies a set of wireless devices
extracted from a plurality of wireless devices which
configure the wireless communication system, namely,
exemplifies rotational polarization wireless devices
304 and 404. Referring to FIG. 4, the rotational
polarization wireless device 304 generally includes a
transmission system (transmission unit), a reception
system (reception unit) and a signal processing system.
The transmission system is configured from an
information signal generator 1, an cyclic code
generation circuit 2, a synchronization code generation
circuit 7, a switch 6, a cosine rotation frequency
generation circuit 4, a sine rotation frequency
generation circuit 14, a carrier frequency generation
circuit 11, power amplifiers 9 and 19, transmission
antennae 10 and 20 and multipliers 3, 5, 8, 13, 15 and
18. The reception system is configured from reception
antennae 80 and 90, low noise amplifiers 81 and 91, a
local oscillation circuit 89, multipliers 82 and 92,
band-pass filters 83 and 93, buffer amplifiers 84 and
94 and delay devices 85 and 95. The signal processing
system includes a digital signal processing circuit 99.
The information signal generator 1, cyclic code
36
generation circuit 2, synchronization code generation
circuit 7, switch 6, cosine rotation frequency
generation circuit 4, sine rotation frequency
generation circuit 14, multipliers 3, 5, 13 and 15,
delay devices 85 and 95 and digital signal processing
circuit 99 configure a digital rotational polarization
wave transmission and reception module 103.
[0064]
Also the rotational polarization wireless device
404 paired with the rotational polarization wireless
device 304 has a configuration similar to that of the
rotational polarization wireless device 304. In
particular, the rotational polarization wireless device
404 generally includes a transmission system
(transmission unit), a reception system (reception
unit) and a signal processing system. The transmission
system is configured from an information signal
generator 51, an cyclic code generation circuit 52, a
synchronization code generation circuit 57, a switch 56,
a cosine rotation frequency generation circuit 54, a
sine rotation frequency generation circuit 64, a
carrier frequency generation circuit 61, power
amplifiers 59 and 69, transmission antennae 60 and 70,
and multipliers 53, 55, 58, 63, 65 and 68. The
reception system is configured from reception antennae
30 and 40, low noise amplifiers 31 and 41, a local
oscillation circuit 39, multipliers 32 and 42, bandpass
filters 33 and 43, buffer amplifiers 34 and 44 and
37
delay devices 35 and 45. The signal processing system
includes a digital signal processing circuit 49. The
information signal generator 51, cyclic code generation
circuit 52, synchronization code generation circuit 57,
switch 56, cosine rotation frequency generation circuit
54, sine rotation frequency generation circuit 64,
multipliers 53, 55, 63 and 65, delay devices 35 and 45
and digital signal processing circuit 49 configure a
digital rotational polarization wave transmission and
reception module 103a.
[0065]
The rotational polarization wireless devices 304
and 404 perform switching between outputs of the cyclic
code generation circuits 2 and 52 and outputs of the
synchronization code generation circuits 7 and 57 in
accordance with control signals of the digital signal
processing circuits 99 and 49 by switches 6 and 56 to
switch codes to be superimposed to outputs of the
information signal generators 1 and 51 between cyclic
codes and synchronization codes, respectively. The
rotational polarization wireless devices 304 and 404
change codes to be superimposed to information signals
within a period of time within which communication is
performed from cyclic codes generated by the cyclic
code generation circuits 2 and 52 to synchronization
codes outputted from the synchronization code
generation circuits 7 and 57, respectively. The
synchronization codes generated by the synchronization
38
code generation circuits 7 and 57 are set such that
they have a stronger correlation in comparison with the
cyclic codes generated by the cyclic code generation
circuits 2 and 52.
[0066]
The configuration of the other part of the
wireless communication system is similar to that in the
first embodiment.
[0067]
Also with the present embodiment configured in
such a manner as described above, similar advantageous
effects to those of the first embodiment can be
achieved.
[0068]
Further, since switching to a synchronization
code having a higher correlation than a cyclic signal
is used, the paired rotational polarization wireless
devices 304 and 404 can acquire timings of the two
wireless devices which use a synchronization signal to
establish synchronism. Accordingly, the detection
accuracy of relative positions on a time axis of
timings of a polarization wave transmitted and received
between rotational polarization wireless devices
configuring the wireless communication system and
received polarization waves can be improved, and
reproduction of an information signal transmitted in a
concealed state can be stabilized.
[0069]
39
Fifth Embodiment
A fifth embodiment of the present invention is
described in detail with reference to FIG. 5.
[0070]
In the present embodiment, the paired rotational
polarization wireless devices in the first embodiment
additionally include a time generation circuit.
[0071]
FIG. 5 is a view schematically depicting a
wireless communication system according to the present
embodiment. In FIG. 5, like elements to those in the
first embodiment are denoted by like reference
characters, and overlapping description of them is
omitted herein.
[0072]
FIG. 5 exemplifies a set of wireless devices
extracted from a plurality of wireless devices which
configure the wireless communication system, namely,
exemplifies rotational polarization wireless devices
305 and 405. Referring to FIG. 5, the rotational
polarization wireless device 305 generally includes a
transmission system (transmission unit), a reception
system (reception unit) and a signal processing system.
The transmission system is configured from an
information signal generator 1, an cyclic code
generation circuit 2, a cosine rotation frequency
generation circuit 4, a sine rotation frequency
generation circuit 14, a carrier frequency generation
40
circuit 11, power amplifiers 9 and 19, transmission
antennae 10 and 20 and multipliers 3, 5, 8, 13, 15 and
18. The reception system is configured from reception
antennae 80 and 90, low noise amplifiers 81 and 91, a
local oscillation circuit 89, multipliers 82 and 92,
band-pass filters 83 and 93, buffer amplifiers 84 and
94 and delay devices 85 and 95. The signal processing
system includes a time generation circuit 98 and a
digital signal processing circuit 99. The information
signal generator 1, cyclic code generation circuit 2,
cosine rotation frequency generation circuit 4, sine
rotation frequency generation circuit 14, multipliers 3,
5, 13 and 15, delay devices 85 and 95, time generation
circuit 98 and digital signal processing circuit 99
configure a digital rotational polarization wave
transmission and reception module 104.
[0073]
Also the rotational polarization wireless device
405 paired with the rotational polarization wireless
device 305 has a configuration similar to that of the
rotational polarization wireless device 305. In
particular, the rotational polarization wireless device
405 generally includes a transmission system
(transmission unit), a reception system (reception
unit) and a signal processing system. The transmission
system is configured from an information signal
generator 51, an cyclic code generation circuit 52, a
cosine rotation frequency generation circuit 54, a sine
41
rotation frequency generation circuit 64, a carrier
frequency generation circuit 61, power amplifiers 59
and 69, transmission antennae 60 and 70, and
multipliers 53, 55, 58, 63, 65 and 68. The reception
system is configured from reception antennae 30 and 40,
low noise amplifiers 31 and 41, local oscillation
circuit 39, multipliers 32 and 42, band-pass filters 33
and 43, buffer amplifiers 34 and 44 and delay devices
35 and 45. The signal processing system includes a time
generation circuit 48 and a digital signal processing
circuit 49. The information signal generator 51, cyclic
code generation circuit 52, cosine rotation frequency
generation circuit 54, sine rotation frequency
generation circuit 64, multipliers 53, 55, 63 and 65,
delay devices 35 and 45, time generation circuit 48 and
digital signal processing circuit 49 configure a
digital rotational polarization wave transmission and
reception module 104a.
[0074]
In the rotational polarization wireless devices
305 and 405, the digital signal processing circuits 49
and 99 detect timings at which the strengths of
polarization waves in information signals exhibit
maximum values within a rotation period and store the
timings into the time generation circuits 48 and 98,
respectively. After the values are stored into the time
generation circuits 48 and 98, within a fixed period
determined in advance, the digital signal processing
42
circuits 49 and 99 determine timings for cyclic code
generation by the cyclic code generation circuits 52
and 2 (transmission timings of control signals), using
the output (the stored time; timing) of the time
generation circuits 48 and 98. Further, after the fixed
period of time elapses, the digital signal processing
circuits 49 and 99 newly detect timings at which the
strengths within a rotation period of polarization
waves of the information signals exhibit maximum values
and store the detected timings in an overwriting manner
into the time generation circuits 48 and 98,
respectively.
[0075]
The configuration of the other part of the
wireless communication system is similar to that in the
first embodiment.
[0076]
Also with the present embodiment configured in
such a manner as described above, similar advantageous
effects to those of the first embodiment can be
achieved.
[0077]
Further, since operation of the digital signal
processing circuits 49 and 99 including the rotational
polarization wireless devices 305 and 405 can be
simplified, power consumption of the rotational
polarization wireless devices 305 and 405 can be
43
reduced and power consumption of the entire wireless
communication system can be reduced.
[0078]
Sixth Embodiment
A sixth embodiment of the present invention is
described in detail with reference to FIG. 6.
[0079]
The present embodiment is configured such that
the paired rotational polarization wireless devices in
the first embodiment include, in addition to a cyclic
code generation circuit, a synchronization code
generation circuit and additionally includes a time
generation circuit. In other words, the present
embodiment has the feathers of the wireless
communication systems of both of the fourth and fifth
embodiments.
[0080]
FIG. 6 is a view schematically depicting a
wireless communication system according the present
embodiment. In FIG. 6, like elements to those in the
first, fourth and fifth embodiments are denoted by like
reference characters, and overlapping description of
them is omitted herein.
[0081]
FIG. 6 exemplifies a set of wireless devices
extracted from a plurality of wireless devices which
configure the wireless communication system, namely,
exemplifies rotational polarization wireless devices
44
306 and 406. Referring to FIG. 6, the rotational
polarization wireless device 306 generally includes a
transmission system (transmission unit), a reception
system (reception unit) and a signal processing system.
The transmission system is configured from an
information signal generator 1, an cyclic code
generation circuit 2, a synchronization code generation
circuit 7, a switch 6, a cosine rotation frequency
generation circuit 4, a sine rotation frequency
generation circuit 14, a carrier frequency generation
circuit 11, power amplifiers 9 and 19, transmission
antennae 10 and 20 and multipliers 3, 5, 8, 13, 15 and
18. The reception system is configured from reception
antennae 80 and 90, low noise amplifiers 81 and 91, a
local oscillation circuit 89, multipliers 82 and 92,
band-pass filters 83 and 93, buffer amplifiers 84 and
94 and delay devices 85 and 95. The signal processing
system includes a time generation circuit 98 and a
digital signal processing circuit 99. The information
signal generator 1, cyclic code generation circuit 2,
synchronization code generation circuit 7, switch 6,
cosine rotation frequency generation circuit 4, sine
rotation frequency generation circuit 14, multipliers 3,
5, 13 and 15, delay devices 85 and 95, time generation
circuit 98 and digital signal processing circuit 99
configure a digital rotational polarization wave
transmission and reception module 105.
[0082]
45
Also the rotational polarization wireless device
406 paired with the rotational polarization wireless
device 306 has a configuration similar to that of the
rotational polarization wireless device 306. In
particular, the rotational polarization wireless device
406 generally includes a transmission system
(transmission unit), a reception system (reception
unit) and a signal processing system. The transmission
system is configured from an information signal
generator 51, an cyclic code generation circuit 52, a
synchronization code generation circuit 57, a switch 56,
a cosine rotation frequency generation circuit 54, a
sine rotation frequency generation circuit 64, a
carrier frequency generation circuit 61, power
amplifiers 59 and 69, transmission antennae 60 and 70,
and multipliers 53, 55, 58, 63, 65 and 68. The
reception system is configured from reception antennae
30 and 40, low noise amplifiers 31 and 41, a local
oscillation circuit 39, multipliers 32 and 42, bandpass
filters 33 and 43, buffer amplifiers 34 and 44 and
delay devices 35 and 45. The signal processing system
includes a time generation circuit 48 and a digital
signal processing circuit 49. The information signal
generator 51, cyclic code generation circuit 52,
synchronization code generation circuit 57, switch 56,
cosine rotation frequency generation circuit 54, sine
rotation frequency generation circuit 64, multipliers
53, 55, 63 and 65, delay devices 35 and 45, time
46
generation circuit 48 and digital signal processing
circuit 49 configure a digital rotational polarization
wave transmission and reception module 105a.
[0083]
The configuration of the other part of the
wireless communication system is similar to that in the
first embodiment.
[0084]
Also with the present embodiment configured in
such a manner as described above, similar advantageous
effects to those of the first, fourth and fifth
embodiments can be achieved.
[0085]
Seventh Embodiment
A seventh embodiment of the present invention is
described in detail with reference to FIG. 7.
[0086]
The present embodiment includes a cyclic code
generation circuit array in place of the cyclic code
generation circuit in the sixth embodiment.
[0087]
FIG. 7 is a view schematically depicting a
wireless communication system according to the present
embodiment. In FIG. 7, like elements to those in the
sixth embodiment are denoted by like reference
characters, and overlapping description of them is
omitted herein.
[0088]
47
FIG. 7 exemplifies a set of wireless devices
extracted from a plurality of wireless devices which
configure the wireless communication system, namely,
exemplifies rotational polarization wireless devices
307 and 407. Referring to FIG. 7, the rotational
polarization wireless device 307 generally includes a
transmission system (transmission unit), a reception
system (reception unit) and a signal processing system.
The transmission system is configured from an
information signal generator 1, a cyclic code
generation circuit array 12, a synchronization code
generation circuit 7, a switch 16, a cosine rotation
frequency generation circuit 4, a sine rotation
frequency generation circuit 14, a carrier frequency
generation circuit 11, power amplifiers 9 and 19,
transmission antennae 10 and 20 and multipliers 3, 5, 8,
13, 15 and 18. The reception system is configured from
reception antennae 80 and 90, low noise amplifiers 81
and 91, a local oscillation circuit 89, multipliers 82
and 92, band-pass filters 83 and 93, buffer amplifiers
84 and 94 and delay devices 85 and 95. The signal
processing system includes a time generation circuit 98
and a digital signal processing circuit 99. The
information signal generator 1, cyclic code generation
circuit array 12, synchronization code generation
circuit 7, switch 16, cosine rotation frequency
generation circuit 4, sine rotation frequency
generation circuit 14, multipliers 3, 5, 13 and 15,
48
delay devices 85 and 95, time generation circuit 98 and
digital signal processing circuit 99 configure a
digital rotational polarization wave transmission and
reception module 106.
[0089]
Also the rotational polarization wireless device
407 paired with the rotational polarization wireless
device 307 has a configuration similar to that of the
rotational polarization wireless device 307. In
particular, the rotational polarization wireless device
407 generally includes a transmission system
(transmission unit), a reception system (reception
unit) and a signal processing system. The transmission
system is configured from an information signal
generator 51, a cyclic code generation circuit array 62,
a synchronization code generation circuit 57, a switch
66, a cosine rotation frequency generation circuit 54,
a sine rotation frequency generation circuit 64, a
carrier frequency generation circuit 61, power
amplifiers 59 and 69, transmission antennae 60 and 70,
and multipliers 53, 55, 58, 63, 65 and 68. The
reception system is configured from reception antennae
30 and 40, low noise amplifiers 31 and 41, a local
oscillation circuit 39, multipliers 32 and 42, bandpass
filters 33 and 43, buffer amplifiers 34 and 44 and
delay devices 35 and 45. The signal processing system
includes a time generation circuit 48 and a digital
signal processing circuit 49. The information signal
49
generator 51, cyclic code generation circuit array 62,
synchronization code generation circuit 57, switch 66,
cosine rotation frequency generation circuit 54, sine
rotation frequency generation circuit 64, multipliers
53, 55, 63 and 65, delay devices 35 and 45, time
generation circuit 48 and digital signal processing
circuit 49 configure a digital rotational polarization
wave transmission and reception module 106a.
[0090]
In the paired rotational polarization wireless
devices 307 and 407, the cyclic code generation circuit
arrays 12 and 62 generate cyclic codes different from
each other but having a weak correlation to each other.
The switches 16 and 66 select codes different from each
other generated by the cyclic code generation circuit
arrays 12 and 62 on the basis of control signals from
the digital signal processing circuits 99 and 49,
respectively, and superimpose the selected codes to
outputs of the information signal generators 1 and 51
through the multipliers 3, 13 and 53, 63, respectively.
By the weak correlation of codes different from each
other to be superimposed to outputs of the information
signal generators 1 and 51, the rotational polarization
wireless devices 307 and 407 can identify a plurality
of rotational polarization wireless devices other than
the own rotation polarization wireless device.
[0091]
50
The configuration of the other part of the
wireless communication system is similar to that in the
sixth embodiment.
[0092]
Also with the present embodiment configured in
such a manner as described above, similar advantageous
effects to those of the sixth embodiment can be
achieved.
[0093]
Further, by switching the cyclic code generation
circuit arrays 12 and 62, it is possible to communicate
information to be transmitted in a concealed state with
a plurality of rotational polarization wireless devices.
Therefore, the region on a time axis in which a
plurality of rotational polarization wireless devices
configuring the wireless communication system can
communicate simultaneously increases, and the
throughput of signal transmission in the wireless
communication system can be improved.
[0094]
Eighth Embodiment
An eighth embodiment of the present invention is
described in detail with reference to FIG. 8.
[0095]
The present embodiment is configured such that a
communication state storage apparatus and a data bus
are provided additionally in the seventh embodiment.
[0096]
51
FIG. 8 schematically depicts a wireless
communication system according to the present
embodiment. In FIG. 8, like elements to those in the
seventh embodiment are denoted by like reference
characters, and overlapping description of them is
omitted herein.
[0097]
FIG. 8 exemplifies a set of wireless devices
extracted from a plurality of wireless devices which
configure the wireless communication system, namely,
exemplifies rotational polarization wireless devices
308 and 408. Referring to FIG. 8, the rotational
polarization wireless device 308 generally includes a
transmission system (transmission unit), a reception
system (reception unit) and a signal processing system.
The transmission system is configured from an
information signal generator 1, a cyclic code
generation circuit array 12, a synchronization code
generation circuit 7, a switch 16, a cosine rotation
frequency generation circuit 4, a sine rotation
frequency generation circuit 14, a carrier frequency
generation circuit 11, power amplifiers 9 and 19,
transmission antennae 10 and 20 and multipliers 3, 5, 8,
13, 15 and 18. The reception system is configured from
reception antennae 80 and 90, low noise amplifiers 81
and 91, a local oscillation circuit 89, multipliers 82
and 92, band-pass filters 83 and 93, buffer amplifiers
84 and 94 and delay devices 85 and 95. The signal
52
processing system includes a communication state
storage apparatus 97, a data bus 96, a time generation
circuit 98 and a digital signal processing circuit 99.
The information signal generator 1, cyclic code
generation circuit array 12, synchronization code
generation circuit 7, switch 16, cosine rotation
frequency generation circuit 4, sine rotation frequency
generation circuit 14, multipliers 3, 5, 13 and 15,
delay devices 85 and 95, communication state storage
apparatus 97, data bus 96, time generation circuit 98
and digital signal processing circuit 99 configure a
digital rotational polarization wave transmission and
reception module 107.
[0098]
Also the rotational polarization wireless device
408 paired with the rotational polarization wireless
device 308 has a configuration similar to that of the
rotational polarization wireless device 308. In
particular, the rotational polarization wireless device
408 generally includes a transmission system
(transmission unit), a reception system (reception
unit) and a signal processing system. The transmission
system is configured from an information signal
generator 51, a cyclic code generation circuit array 62,
a synchronization code generation circuit 57, a switch
66, a cosine rotation frequency generation circuit 54,
a sine rotation frequency generation circuit 64, a
carrier frequency generation circuit 61, power
53
amplifiers 59 and 69, transmission antennae 60 and 70,
and multipliers 53, 55, 58, 63, 65 and 68. The
reception system is configured from reception antennae
30 and 40, low noise amplifiers 31 and 41, a local
oscillation circuit 39, multipliers 32 and 42, bandpass
filters 33 and 43, buffer amplifiers 34 and 44 and
delay devices 35 and 45. The signal processing system
includes a communication state storage apparatus 47, a
data bus 46, a time generation circuit 48 and a digital
signal processing circuit 49. The information signal
generator 51, cyclic code generation circuit array 62,
synchronization code generation circuit 57, switch 66,
cosine rotation frequency generation circuit 54, sine
rotation frequency generation circuit 64, multipliers
53, 55, 63 and 65, delay devices 35 and 45,
communication state storage apparatus 47, data bus 46,
time generation circuit 48 and digital signal
processing circuit 49 configure a digital rotational
polarization wave transmission and reception module
107a.
[0099]
In the paired rotational polarization wireless
devices 308 and 408, the communication state storage
apparatus 47 and 97 are coupled to the digital signal
processing circuits 49 and 99, respectively, and store
information of polarization angle differences of
transmitted polarization waves and received
polarization waves between the paired rotational
54
polarization wireless devices 308 and 408 in a time
series and then transmit the information to the outside
using the data buses 46 and 96, respectively.
[0100]
The configuration of the other part of the
wireless communication system is similar to that in the
seventh embodiment.
[0101]
Also with the present embodiment configured in
such a manner as described above, similar advantageous
effects to those of the seventh embodiment can be
achieved.
[0102]
Further, by checking the variation of the angle
difference between polarization waves in a time series,
an environmental variation which has an influence on
radio wave propagation around the wireless
communication system. Therefore, the timing for
maintenance for allowing the wireless communication
system to operate stably can be detected. Therefore,
stabilization of the wireless communication system can
be anticipated, and the time required for system
restoration when an eventuality occurs can be reduced.
[0103]
Ninth Embodiment
A ninth embodiment of the present invention is
described in detail with reference to FIG. 9.
[0104]
55
The present embodiment is configured such that
the transmission antenna and the reception antenna in
the first embodiment are used commonly for transmission
and reception using a circulator.
[0105]
FIG. 9 is a view schematically depicting a
wireless communication system according to the present
embodiment. In FIG. 9, like elements to those in the
seventh embodiment are denoted by like reference
characters, and overlapping description of them is
omitted herein.
[0106]
FIG. 9 exemplifies a rotational polarization
wireless device 309 extracted from a pair of wireless
devices which configure the wireless communication
system for simplified illustration.
[0107]
Referring to FIG. 9, the rotational polarization
wireless device 309 generally includes a transmission
system (transmission unit), a reception system
(reception unit) and a signal processing system. The
transmission system is configured from an information
signal generator 1, a cyclic code generation circuit 2,
a cosine rotation frequency generation circuit 4, a
sine rotation frequency generation circuit 14, a
carrier frequency generation circuit 11, power
amplifiers 9 and 19, duplexer antennae 78 and 88,
circulators 21 and 22 and multipliers 3, 5, 8, 13, 15
56
and 18. The reception system is configured from the
duplexer antennae 78 and 88 (shared by the transmission
unit), the circulators 21 and 22 (shared by the
transmission unit), low noise amplifiers 81 and 91, a
local oscillation circuit 89, multipliers 82 and 92,
band-pass filters 83 and 93, buffer amplifiers 84 and
94 and delay devices 85 and 95. The signal processing
system includes a digital signal processing circuit 99.
The information signal generator 1, cyclic code
generation circuit 2, cosine rotation frequency
generation circuit 4, sine rotation frequency
generation circuit 14, multipliers 3, 5, 13 and 15,
delay devices 85 and 95 and digital signal processing
circuit 99 configure a digital rotational polarization
wave transmission and reception module 101.
[0108]
Also the rotational polarization wireless device
paired with the rotational polarization wireless device
309 has a configuration similar to that of the
rotational polarization wireless device 309. It is to
be noted that the rotational polarization wireless
device paired with the rotational polarization wireless
device 309 may be configured similarly to the
rotational polarization wireless device 401 in the
first embodiment.
[0109]
In the rotational polarization wireless device
309, an output of the cyclic code generation circuit 2
57
is superimposed by the multiplier 3 to one of two
outputs branched from the information signal generator
1 and is then multiplied by an output of the cosine
rotation frequency generation circuit 4 by the
multiplier 5, whereafter it is multiplied by an output
of the carrier frequency generation circuit 11 by the
multiplier 8 and then inputted to a first terminal of
the circulator 21 through the power amplifier 9.
Further, in the rotational polarization wireless device
309, an output of the cyclic code generation circuit 2
is superimposed by the multiplier 13 to the other one
of the two outputs branched from the information signal
generator 1 and is multiplied by an output of the sine
rotation frequency generation circuit 14 by the
multiplier 15, whereafter is it multiplied by an output
of the carrier frequency generation circuit 11 by the
multiplier 18 and then is inputted to a first terminal
of the circulator 22 through the power amplifier 19.
[0110]
In the rotational polarization wireless device
309, an output from a third terminal of the circulator
21 is amplified by the low noise amplifier 81 and then
multiplied by an output of the local oscillation
circuit 89, which generates a signal of a frequency
equal to the carrier frequency, by the multiplier 82.
Then, an output of the multiplier 82 is inputted to the
buffer amplifier 84 through the band-pass filter 83,
and an output of the buffer amplifier 84 is
58
successively delayed by the delay device 85 and then
inputted to the digital signal processing circuit 99.
Further, in the rotational polarization wireless device
309, an output of a third terminal of the circulator 22
is amplified by the low noise amplifier 91 and is then
multiplied by an output of the local oscillation
circuit 89, which generates a signal of a frequency
equal to the carrier frequency, by the multiplier 92.
Then, an output of the multiplier 92 is inputted to the
buffer amplifier 94 through the band-pass filter 93,
and an output of the buffer amplifier 94 is
successively delayed by the delay device 95 and then
inputted to the digital signal processing circuit 99.
[0111]
Second terminals of the circulators 21 and 22
are coupled to the duplexer antennae 78 and 88,
respectively. Since the circulators 21 and 22 transmit
a signal in a circulation order of terminals thereof,
the duplexer antennae 78 and 88 radiate outputs of the
power amplifiers 9 and 19 into the space, and power of
an electromagnetic wave arriving at the rotational
polarization wireless device 309 is inputted to the low
noise amplifiers 81 and 91.
[0112]
The configuration of the other part of the
wireless communication system is similar to that in the
first embodiment.
[0113]
59
Also with the present embodiment configured in
such a manner as described above, similar advantageous
effects to those of the first embodiment can be
achieved.
[0114]
Further, since an antenna can be used commonly
for transmission and reception, the size of the
rotational polarization wireless devices which
configure the wireless communication system can be
reduced, and the fabrication cost for the rotational
polarization wireless devices can be reduced.
[0115]
Tenth Embodiment
A tenth embodiment of the present invention is
described in detail with reference to FIG. 10.
[0116]
In the present embodiment, an antenna switch is
used in place of the circulator in the ninth embodiment.
[0117]
FIG. 10 is a view schematically depicting a
wireless communication system according to the present
embodiment. In FIG. 10, like elements to those in the
ninth embodiment are denoted by like reference
characters, and overlapping description of them is
omitted herein.
[0118]
FIG. 10 exemplifies a rotational polarization
wireless device 310 extracted from a pair of wireless
60
devices which configure the wireless communication
system for simplified illustration.
[0119]
Referring to FIG. 10, the rotational
polarization wireless device 310 generally includes a
transmission system (transmission unit), a reception
system (reception unit) and a signal processing system.
The transmission system is configured from an
information signal generator 1, a cyclic code
generation circuit 2, a cosine rotation frequency
generation circuit 4, a sine rotation frequency
generation circuit 14, a carrier frequency generation
circuit 11, power amplifiers 9 and 19, duplexer
antennae 78 and 88, antenna switches 23 and 24 and
multipliers 3, 5, 8, 13, 15 and 18. The reception
system is configured from the duplexer antennae 78 and
88 (shared by the transmission unit), the antenna
switches 23 and 24 (shared by the transmission unit),
low noise amplifiers 81 and 91, a local oscillation
circuit 89, multipliers 82 and 92, band-pass filters 83
and 93, buffer amplifiers 84 and 94 and delay devices
85 and 95. The signal processing system includes a
digital signal processing circuit 99. The information
signal generator 1, cyclic code generation circuit 2,
cosine rotation frequency generation circuit 4, sine
rotation frequency generation circuit 14, multipliers 3,
5, 13 and 15, delay devices 85 and 95 and digital
signal processing circuit 99 configure a digital
61
rotational polarization wave transmission and reception
module 101.
[0120]
In the rotational polarization wireless device
310, an input terminal and an output terminal of the
antenna switch 23 are coupled to an output of the power
amplifier 9 and an input of the low noise amplifier 81,
respectively, and a common terminal of the antenna
switch 23 is coupled to the duplexer antenna 78.
Meanwhile, an input terminal and an output terminal of
the antenna switch 24 are coupled to an output of the
power amplifier 19 and an input of the low noise
amplifier 91, respectively, and a common terminal of
the antenna switch 24 is coupled to the duplexer
antenna 88. The antenna switches 23 and 24 are
controlled by the digital signal processing circuit 99
and perform transmission and reception timedivisionally.
[0121]
The configuration of the other part of the
wireless communication system is similar to that in the
ninth embodiment.
[0122]
Also with the present embodiment configured in
such a manner as described above, similar advantageous
effects to those of the ninth embodiment can be
achieved.
[0123]
62
Further, since the present embodiment does not
use a circulator which is comparatively great in size
and heavy, the rotational polarization wireless devices
which configure the wireless communication system can
be reduced in dimension and weight, and the fabrication
cost of the rotational polarization wireless devices
can be reduced.
[0124]
Eleventh Embodiment
An eleventh embodiment of the present invention
is described in detail with reference to FIG. 11.
[0125]
In the present embodiment, the transmission unit
is changed in configuration from the ninth embodiment.
[0126]
FIG. 11 is a view schematically depicting a
wireless communication system according to the present
embodiment. In FIG. 11, like elements to those in the
ninth embodiment are denoted by like reference
characters, and overlapping description of them is
omitted herein.
[0127]
FIG. 11 exemplifies a rotational polarization
wireless device 311 extracted from a pair of wireless
devices which configure the wireless communication
system for simplified illustration.
[0128]
63
Referring to FIG. 11, the rotational
polarization wireless device 311 generally includes a
transmission system (transmission unit), a reception
system (reception unit) and a signal processing system.
The transmission system is configured from cosine wave
carrier generation circuits 72 and 73, sine wave
carrier generation circuits 76 and 77, an information
signal generator 1, a cyclic code generation circuit 2,
a clock generation circuit 29, delta sigma circuits 27
and 28, band-pass filters 25 and 26, power amplifiers 9
and 19, duplexer antennae 78 and 88, circulators 21 and
22, an adder 71, a subtractor 75 and multipliers 3, 13,
74 and 79. The reception system is configured from the
duplexer antennae 78 and 88 (shared by the transmission
unit), the circulators 21 and 22 (shared by the
transmission unit), low noise amplifiers 81 and 91, a
local oscillation circuit 89, multipliers 82 and 92,
band-pass filters 83 and 93, buffer amplifiers 84 and
94 and delay devices 85 and 95. The signal processing
system includes a digital signal processing circuit 99.
The cosine wave carrier generation circuits 72 and 73,
sine wave carrier generation circuits 76 and 77,
information signal generator 1, cyclic code generation
circuit 2, clock generation circuit 29, delta sigma
circuits 27 and 28, multipliers 3, 13, 74 and 79, delay
devices 85 and 95 and digital signal processing circuit
99 configure a digital rotational polarization wave
transmission and reception module 110.
64
[0129]
In the rotational polarization wireless device
311, a beat-state carrier formed by adding outputs of
the cosine wave carrier generation circuits 72 and 73
by the adder 71 is multiplied by the multiplier 74 by
one of the two outputs branched from the information
signal generator 1 and is superimposed to an output of
the cyclic code generation circuit 2 by the multiplier
3, whereafter it is multiplied by the delta sigma
circuit 27, passes through the band-pass filter 25,
amplified by the power amplifier 9, and then inputted
to a first terminal of the circulator 21. Meanwhile, a
beat-state carrier formed by calculating a difference
between outputs of the sine wave carrier generation
circuits 76 and 77 by the subtractor 75 is multiplied
by the other one of the two branch outputs of the
information signal generator 1 by the multiplier 79 and
then is superimposed to an output of the cyclic code
generation circuit 2 by the multiplier 13, whereafter
it is multiplied by the delta sigma circuit 28, passed
through the band-pass filter 26, amplified by the power
amplifier 19 and inputted to a first terminal of the
circulator 22.
[0130]
In the rotational polarization wireless device
311, an output of a third terminal of the circulator 21
is amplified by the low noise amplifier 81 and
multiplied by the multiplier 82 by an output of the
65
local oscillation circuit 89, which generates a signal
of a frequency equal to the carrier frequency, and an
output of the multiplier 82 is inputted to the buffer
amplifier 84 through the band-pass filter 83. Then, an
output of the buffer amplifier 84 is successively
delayed by the delay device 85 and inputted to the
digital signal processing circuit 99. Meanwhile, an
output of a third terminal of the circulator 22 is
amplified by the low noise amplifier 91 and is
multiplied by the multiplier 92 by an output of the
local oscillation circuit 89, which generates a signal
of a frequency equal to the carrier frequency, and an
output of the multiplier 92 is inputted to the buffer
amplifier 94 through the band-pass filter 93. Then, an
output of the buffer amplifier 94 is successively
delayed by the delay device 95 and inputted to the
digital signal processing circuit 99.
[0131]
Second terminals of the circulators 21 and 22
are coupled to the duplexer antennae 78 and 88,
respectively. To the delta sigma circuits 27 and 28, an
operation clock is supplied from the clock generation
circuit 29. Since the circulators 21 and 22 transmit a
signal in an order of circulation of their terminals,
the duplexer antennae 78 and 88 radiate outputs of the
power amplifiers 9 and 19 into the space and power of
electromagnetic waves arriving at the rotational
66
polarization wireless device 309 is inputted to the low
noise amplifiers 81 and 91.
[0132]
The configuration of the other part of the
wireless communication system is similar to that in the
ninth embodiment.
[0133]
Also with the present embodiment configured in
such a manner as described above, similar advantageous
effects to those of the ninth embodiment can be
achieved.
[0134]
Further, since generation of an input signal to
the power amplifiers and processing of output signals
of the low noise amplifiers can be implemented all by
digital circuits, the size of the rotational
polarization wireless devices which configure the
wireless communication system can be reduced, and the
fabrication cost for the rotational polarization
wireless devices can be reduced. Further, an elongated
life of the rotational polarization wireless devices
can be implemented.
[0135]
Twelfth Embodiment
A twelfth embodiment of the present invention is
described in detail with reference to FIG. 12.
[0136]
67
In the present embodiment, the wireless
communication systems described in connection with the
first to eleventh embodiments are applied to an
elevator controlling system.
[0137]
FIG. 12 is a view schematically depicting an
elevator controlling system to which the wireless
communication system according to the present
embodiment is applied.
[0138]
Referring to FIG. 12, the elevator system 1100
moves an elevator cab 1111 in the inside of a building
1101. A base station wireless device 1103 (1103a,
1103b) and an orthogonal polarization integrated
antenna 1102 (1102a, 1102b) coupled to each other are
provided on each of the floor and the ceiling of the
inside of the building 1101. The base station wireless
device 1103 includes a transmitter and a receiver of
the wireless communication system for detecting a
propagation path modification act of an outsider and
compensating for degradation of communication quality
between transmission and reception against the
modification. An orthogonal polarization integrated
antenna 1112 (1112a, 1112b) is provided on each of the
outer side of the floor and the outer side of the
ceiling of the elevator cab 1111. The orthogonal
polarization integrated antenna 1112 is coupled to a
terminal station wireless device 1113, which includes a
68
transmitter and a receiver of the wireless
communication system which detects a propagation path
modification act and compensates for degradation of the
communication quality between transmission and
reception against the modification, using a high
frequency cable 1114. The base station wireless device
1103 and the terminal station wireless device 1113 use
the inside of the building 1101 as a wireless
transmission medium, and therefore, electronic waves
undergo multiple reflection by inner walls of the
building 1101 and outer walls of the elevator cab 1111.
Therefore, a multiple-wave interface environment is
formed.
[0139]
In the present embodiment, a propagation path
modification act from an outsider is detected under a
multiple-wave interference environment, and wireless
transmission of high quality which compensates for
degradation of the communication quality between
transmission and reception against the modification can
be implemented. Therefore, control and supervision of
the elevator cab 1111 can be carried out remotely
without using wire connection means from the building
1101, and wire connection means such as a cable can be
omitted. Further, the same transport capacity can be
implemented by a smaller building volume. Or,
improvement in transport capacity by increasing the
69
size of an elevator by a same building volume can be
implemented.
[0140]
Thirteenth Embodiment
A thirteenth embodiment of the present invention
is described in detail with reference to FIG. 13.
[0141]
In the present embodiment, the wireless
communication systems described in connection with the
first to eleventh embodiments are applied to an
elevator controlling system.
[0142]
FIG. 13 is a view schematically depicting a
transformer substation controlling system to which the
wireless communication system according to the present
embodiment is applied.
[0143]
Referring to FIG. 13, the substation equipment
monitoring system 1200 includes a plurality of
substation machines 1201, in each of which a terminal
station wireless device 1203 and a terminal station
rotational polarization antenna 1202 as a rotational
polarization wireless device configuring a wireless
communication system of the present invention are
provided in a coupled state to each other. A plural
number of local station apparatus 1211 smaller than the
number of substation machines 1201 are provided in the
proximity of the substation machines 1201. In each of
70
the local station apparatus 1211, a base station
wireless device 1213 and a base station rotational
polarization antenna 1212 as a rotational polarization
wireless device configuring a wireless communication
system of the present invention are provided in a
coupled state to each other are provided in a coupled
state to each other.
[0144]
The substation machines 1201 have a size of an
order of several meters. Since the size is
overwhelmingly great in comparison with a wavelength of
several hundred MHz to several GHz which corresponds to
a frequency of electromagnetic waves used by the
rotational polarization wireless devices, the
electromagnetic waves are subject to multiple
reflections by the plural substation machines 1201,
whereby a multiple wave interference environment is
formed.
[0145]
In the present embodiment, wireless transmission
of high quality which compensates for degradation of
the communication quality between transmission and
reception can be implemented using a plurality of
reflection waves under a multiple reflection
interference environment. Therefore, control and
supervision of the substation machines 1201 can be
carried out remotely by a plurality of local station
apparatus 1211 without using wire coupling means.
71
Further, by solving the problem of high voltage
inductive power which is a problem where wire coupling
means such as a cable is used, the cost required to lay
cables can be deleted. Therefore, improvement in safety
and reduction of the cost of the control and
supervision system for the substation machines 1201 can
be anticipated.
[0146]
It is to be noted that the present invention is
not limited to the embodiments described above but can
be carried out in various modified forms. For example,
the embodiments have been described in detail in order
to facilitate understandings of the present invention
and the invention is not necessarily limited to
embodiments which include all of the components
described hereinabove.
DESCRIPTION OF REFERENCE CHARACTERS
[0147]
1: Information signal generator
2: Cyclic code generation circuit
3, 5, 8, 13, 15, 18: Multipliers
4: Cosine rotation frequency generation circuit
6, 16: Switches
7: Synchronization code generation circuit
9, 19: Power amplifiers
10, 20: Transmission antennae
11: Carrier frequency generation circuit
72
12: Cyclic code generation circuit array
14: Sine rotation frequency generation circuit
21, 22: Circulators
23, 24: Antenna switches
25, 26: Band-pass filters
27, 28: Delta sigma circuits
29: Clock generation circuit
30, 40: Reception antennae
31, 41: Low noise amplifiers
32, 42: Multipliers
33, 43: Band-pass filters
34, 44: Buffer amplifiers
35, 35a, 35b, 35n: Delay devices
39: Local oscillation circuit
45, 45a, 45b, 45n: Delay devices
46: Data bus
47: Communication state storage apparatus
48: Time generation circuit
49: Digital signal processing circuit
51: Information signal generator
52: Cyclic code generation circuit
53, 55, 58, 63, 65, 68: Multipliers
54: Cosine rotation frequency generation circuit
56, 66: Switches
57: Synchronization code generation circuit
59, 69: Amplifiers
60, 70: Transmission antennae
61: Carrier frequency generation circuit
73
62: Cyclic code generation circuit array
64: Sine rotation frequency generation circuit
71: Adder
72, 73: Cosine wave carrier generation circuits
74, 79: Multipliers
75: Subtractor
76, 77: Sine wave carrier generation circuits
78, 88: Duplexer antennae
80, 90: Reception antennae
81, 91: Low noise amplifiers
82, 92: Multipliers
83, 93: Band-pass filters
84, 94: Buffer amplifiers
85, 85a, 85b, 85n: Delay devices
89: Local oscillation circuit
95, 95a, 95b, 95n: Delay devices
96: Data bus
97: Communication state storage apparatus
98: Time generation circuit
99: Digital signal processing circuit
101-107: Digital rotational polarization wave
transmission and reception modules
101a-107a: Digital rotational polarization wave
transmission and reception modules
110, 201: Digital rotational polarization wave
transmission and reception modules
301-311: Rotational polarization wireless devices
401-408: Rotational polarization wireless devices
74
1100: Elevator system
1101: Building
1102: Orthogonal polarization integrated antenna
1103: Base station wireless device
1111: Elevator cab
1112: Orthogonal polarization integrated antenna
1113: Terminal station wireless device
1114: High frequency cable
1200: Substation equipment monitoring system
1201: Substation machine
1202: Terminal station rotational polarization antenna
1203: Terminal station wireless device
1211: Local station apparatus
1212: Base station rotational polarization antenna
1213: Base station wireless device
75
We claim:
1. A wireless communication system, comprising:
a plurality of wireless devices configured to
communicate with each other;
each of the wireless devices including:
a transmission unit configured to
transmit a carrier of a fixed strength with
polarization waves thereof rotated to a different one
of the wireless devices using two antennae spatially
orthogonal to each other;
a reception unit configured to receive a
carrier transmitted from the transmission unit of the
different wireless device; and
a timing detection unit configured to
detect a timing at which the polarization waves of the
carrier received by the reception unit within a period
of rotation indicates a maximum strength;
the transmission unit performing transmission or
reception of a specific information signal using the
carrier based on the timing detected by the timing
detection unit.
2. The wireless communication system according
to claim 1, wherein
the transmission units of the plurality of
wireless devices have a common cyclic code and
superimpose the cyclic code to the information signal
76
using the timing detected by the timing detection unit
as a reference point.
3. The wireless communication system according
to claim 1, wherein
the transmission units of the plurality of
wireless devices have a plurality of cyclic codes
different from each other that are common to those of
the other ones of the plurality of wireless devices and
performs switching of the plurality of different cyclic
codes at a timing based on the timing detected by the
timing detection unit so as to superimpose one of the
cyclic codes to the information signal.
4. The wireless communication system according
to claim 1, wherein
the transmission units of the plurality of
wireless devices have a common synchronization code and
superimpose the synchronization code to the information
signal at a timing different from the timing at which
the cyclic code is used such that synchronism of a
period of rotation of polarization waves of the carrier
is established between the plurality of radio waves.
5. The wireless communication system according
to claim 2, wherein
each of the wireless devices further includes a
timer configured to store the timing detected by the
timing detection unit, and
the transmission unit superimposes the cyclic
code to the information signal at a timing based on the
77
timing stored in the timer and a period of rotation of
polarization waves of the carrier.
6. The wireless communication system according
to claim 1, wherein
each of the wireless devices further includes a
log memory configured to store information of the
timing detected by the timing detection unit in a time
series, and
the transmission unit detects a situation
variation of a wireless environment surrounding the
wireless device based on information of the timing
stored in the log memory.
7. The wireless communication system according
to claim 1, wherein
at least one pair of ones of the plurality of
wireless devices are different from each other in
direction of rotation of polarization waves of the
carrier.
8. A wireless communication system, comprising:
a plurality of wireless devices configured to
communicate with each other and including a rotational
polarization wireless device configured to transmit
rotational polarization waves and a fixed polarization
wireless device configured to transmit linear
polarization waves;
the rotational polarization wireless device
including a first transmission unit configured to
transmit a carrier of a fixed strength with
78
polarization waves thereof rotated to the fixed
polarization wireless device using two antennae
spatially orthogonal to each other, a first reception
unit configured to receive a carrier transmitted from
the second transmission unit of the fixed polarization
wireless device, and a first timing detection unit
configured to detect a timing at which the polarization
waves of the carrier received by the first reception
unit indicates a maximum strength, the first
transmission unit performing transmission or reception
of a specific information signal that uses the carrier
based on the timing detected by the first timing
detection unit;
the fixed polarization wireless device including
a second transmission unit configured to transmit
linear polarization waves of a carrier of a fixed
strength to the rotational polarization wireless device
using one antenna, a second reception unit configured
to receive a carrier transmitted from the first
transmission unit of the rotational polarization
wireless device using one antenna, and a second timing
detection unit configured to detect a timing at which
the polarization waves of the carrier received by the
second reception unit indicate a maximum intensity
within a period of rotation of the polarization waves
of the carrier received by the second reception unit,
the second transmission unit performing transmission or
reception of a specific information signal that uses
79
the carrier based on the timing detected by the second
timing detection unit.
9. The wireless communication system according
to claim 8, wherein
the first transmission unit of the rotational
polarization wireless device and the second
transmission unit of the fixed polarization wireless
device have a common cyclic code and superimpose the
cyclic code to the information signal using the timing
detected by the first or second timing detection unit
as a reference point.
10. The wireless communication system according
to claim 1, wherein
the transmission unit includes a cosine wave
generation circuit and a sine wave generation unit
configured to generate a cosine wave and a sine wave of
a first frequency, respectively, and another cosine
wave generation circuit and another sine wave
generation circuit configured to generate a cosine wave
and a sine wave of a second frequency different from
the first frequency, respectively, and
the polarization waves of the carrier are
rotated by a frequency equal to one half a difference
between the first frequency and the second frequency.
11. An elevator controlling system, comprising:
an elevator cab configured to move up and down
in the inside of a building; and
80
the wireless devices of the wireless
communication system according to claim 1 each disposed
at corresponding one end and the other end of a range
of movement of the elevator cab in the inside of the
building.
12. A substation controlling system, comprising:
a plurality of substation machines disposed in
electric substation equipment;
at least one base station apparatus configured
to control the plurality of substation machines, the
number of the base station apparatus being smaller than
the number of the substation machines; and
the wireless devices of the wireless
communication system according to claim 1 each disposed
at corresponding one of the plurality of substation
machines and the base station apparatus.