JP2003018054A - Radio communication method and system, and communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system and method for further reducing interference in each of 2nd communication devices receiving signals. SOLUTION: The radio communication method includes steps of: generating transmission channel coefficient information on the basis of information, representing the relation between a pilot signal sent from a 1st communication device by using each antenna beam and a signal corresponding to the pilot signal received by using each of the 2nd communication devices; calculating, on the basis of the transmission line coefficient information, a conversion operator by which a signal received by using each 2nd communication device becomes a signal to be transmitted, when the transmission signal to be sent by using each antenna beam obtained by converting the signal to be delivered to each 2nd communication unit by using the conversion operator; and converting the signal to be delivered to each 2nd communication unit by using each antenna beam by using the conversion operator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system for realizing wireless communication between a mobile station and a base station, and more particularly, to a plurality of receiving stations from a plurality of antennas of a transmitting station. Signal transmission on the same radio channel (same frequency)
The present invention relates to a wireless communication method and system.

[0002]

2. Description of the Related Art Implementing wireless communication between a transmitting station and a plurality of receiving stations on the same wireless channel (same frequency) means that frequency utilization efficiency in the wireless communication system can be improved. However, in this case, a problem of interference occurs in wireless communication between the transmitting station and the plurality of receiving stations.

In order to solve the problem of such interference, the following methods have been conventionally proposed.

As a wireless communication system, for example, FIG.
Consider a mobile communication system as shown in FIG.

In FIG. 27, a radio base station 101 and N mobile stations 200 (1) (MS1) to 200 (N) (MS
N) wireless communication is performed. Wireless base station 101
Has an antenna device 203 having M antenna elements # 1 to #M, and from each antenna element # 1 to #M of this antenna device 103 to each mobile station 200 (1) to 200.
The co-channel signal is transmitted toward (N).

In this case, the signals are mixed in the transmission space, and noise other than the desired signal, that is, interference occurs. For example, when the signals S1 to SM are transmitted from the antenna elements # 1 to #M of the antenna device 103 in the radio base station 101, the signals R from the mobile stations 200 (1) to 200 (N) are transmitted.
1 to RN are received. Transmission signals S1 to SM and reception signal R1
~ RN is the transmission line coefficient of the space associated with each
Then, the received signals R1 to RN are expressed as follows.

[0007]

[Equation 3] When these relationships are displayed in a matrix, [R] = [h] · [S] (2)

Assuming that the desired signal is S1 in the mobile station 200 (1) (received signal R1), the terms other than S1 in the first row in equation (1) (h21.S2 + ... + hM1.SM).
Not only become interference, but the received signal R1 is
It is also affected by the transmission line coefficient h11 (state of the transmission line).

Therefore, in the conventional system, interference is reduced by using an adaptive array antenna. That is, for example, in the mobile station 200 (1) (received signal R1), the influence of the transmission path coefficient (h21, h31, ..., hM1) of the interference signal (h21.S2 + ... + hM1.SM) is minimized. I have to. Specifically, as shown in FIG. 27, weights W1 to WM are attached to the signals from the antenna elements # 1 to #M, the term of the transmission path coefficient h11 is maximum, and the other transmission path coefficients h21, The terms of h31, ..., hM1 are minimized. Since these weights can be determined independently for each signal, the number is M × N.

[0010]

In the technique of determining the weight for each transmission signal by using the adaptive array antenna as described above and reducing the interference amount with respect to the reception signal of each mobile station, for example, the mobile station 200 (1 ) Not only optimizing the weight for the signal S1 corresponding to the received signal R1 but also all the signals S1, S2, ...
The weight for SN must be optimized. Even if the weight for the signal S1 is optimized, the transmission capacity and subscriber capacity of the entire system cannot be increased if the quality of the received signal for other mobile stations deteriorates even if the weight is optimized. Therefore, each weight is equivalent to the total signal S1.
It is necessary to obtain the optimum value in consideration of SN.

Especially in the downlink channel (transmitted by the radio base station and received by the mobile station), it is very difficult to optimize this weight. The quality of the signals S1 to SN depends on the received signals R1 to
Since it is derived from RN, it is necessary to transmit the quality of the signal S at each mobile station, for example, the quality information SN of the signal S1 at the mobile station 200 (1) (MS1) to the radio base station 101. The radio base station 101 is the mobile station 200
Signal quality information (SN (S
1) to SN (SN)), and the optimum value of each weight, that is, the optimum antenna pattern is derived based on the information.

However, it is necessary to repeat the process of deriving the optimum values of all the weights for obtaining the optimum antenna pattern in all mobile stations, and the signal quality information (SN (S1) to SN (SN)) from each mobile station is required. (SN)) does not directly determine the optimum value for each weight. Therefore, an extremely large amount of information is exchanged between the base station and each mobile station, which requires a huge amount of processing. As a result, the original data transmission between the base station and each mobile station is hindered. Further, even if the antenna pattern is determined by the weights thus optimized, it is generally difficult to completely eliminate the interference at all mobile stations.

Therefore, an object of the present invention is to make it relatively easy for each second communication device to transmit a signal from a plurality of antennas of the first communication device to a plurality of second communication devices. It is an object of the present invention to provide a wireless communication method and system capable of reducing the interference of the wireless communication.

[0014]

In order to solve the above problems, the present invention provides a first communication device having a plurality of antennas and a plurality of second communication devices as described in claim 1. In the wireless communication method when performing wireless communication between
A pilot signal transmission procedure for transmitting a pilot signal corresponding to each antenna beam from the first communication device to the plurality of second communication devices with a plurality of antenna beams, and with each antenna beam from the first communication device. The first communication device and the second communication device formed by each antenna beam based on the information indicating the relationship between the transmitted pilot signal and the signal corresponding to the pilot signal received by each second communication device A transmission path coefficient information generation procedure for generating transmission path coefficient information indicating a state of a transmission path with a communication device, and a signal obtained by converting a signal to be transmitted to each second communication device with a conversion operator. When the transmission signal to be transmitted by the antenna beam is transmitted by each of the antenna beams, the conversion operator is set so that the received signal at each second communication device becomes the signal to be transmitted. A conversion operator calculation procedure for calculating based on information, a signal conversion procedure for converting a signal to be transmitted to each second communication device using the conversion operator into a transmission signal to be transmitted by each antenna beam, And a signal transmission procedure for transmitting the transmission signal obtained by the conversion from the first communication device using each antenna beam.

In such a wireless communication method, conversion is performed on the basis of transmission line coefficient information representing the state of each transmission line formed between each antenna beam between the first communication device and each second communication device. Since the operator is calculated, this conversion conversion operator depends on the state of the transmission path between the first communication device and each second communication device. Then, the conversion operator transmits a transmission signal to be transmitted by each antenna beam obtained by converting the signal to be transmitted to each second communication device by the conversion operator. At this time, the signal received by each second communication device is determined to be the signal to be transmitted. Therefore, by transmitting each transmission signal obtained by converting the signal to be transmitted to each second communication device by the above conversion operator, each second communication device is in a state where there is no interference. You will be able to receive the signal to be transmitted.

The processing according to the above-mentioned transmission path coefficient information generation procedure can be shared by each second communication device and each first communication device. In addition, a device other than each second communication device and first communication device (for example, a control station in the case of a mobile communication system) may partially perform a process according to the transmission path coefficient information generation procedure. You can also

According to the present invention, when the number of antenna beams formed in the first communication device is the same as the number N of the second communication devices, the transmission path is defined as described in claim 2. The coefficient information generation procedure is performed by the pilot signal Pk transmitted by each antenna beam #k (k = 1 to N) from the first communication device.
And the transmission signal D from each antenna beam # 1 to #N based on the information indicating the relationship between the received signal at each second communication device i (i = 1 to N) corresponding to the pilot signal Pk.
1 to DN and received signals R1 to RN at each second communication device 1 to N
[R] = [H] · [D] [R]: 1 × N matrix consisting of elements R1 to RN [D]: 1 × N matrix consisting of elements D1 to DN [H]: From element hki A transmission channel coefficient matrix [H] represented as the following N × N matrix (k, i = 1 to N) is generated as transmission channel coefficient information, and the conversion operator calculation procedure is the transmission channel coefficient matrix [H]. The conversion operator represented by the inverse matrix [H] ⁻¹ of the above is calculated, and the signal conversion procedure is performed by converting the signals [S] = S1 to SN to be transmitted to the respective second communication devices 1 to N into [D ] = [H] ⁻¹ · [S], the signals to be transmitted by each antenna beam # 1 to #N are converted into [D] = D1 to DN, and
The signals D1 to DN obtained by the above conversion can be configured to be transmitted from each of the antenna beams # 1 to #N from the first communication device.

In such a wireless communication method, the received signals [R] = R1 to RN at the second communication devices 1 to N are Therefore, each of the second communication devices 1 to N receives only the signal [S] = S1 to SN to be transmitted to each of them.

According to the present invention, from the viewpoint that the processing according to the transmission path coefficient information generation procedure is efficiently shared by the first communication device and each second communication device. In each of the wireless communication methods, the transmission path coefficient information generation procedure includes a pilot signal transmitted by each antenna beam from the first communication device and the pilot signal received by each second communication device. The first procedure of acquiring information indicating the relationship with the signal corresponding to each of the second communication devices, and the above information acquired by each of the second communication devices from each of the second communication devices. Can be configured to include a second procedure for notifying the communication apparatus of No. 1 and a third procedure for generating transmission path coefficient information based on the notified information in the first communication apparatus.

From the viewpoint that the transmission path coefficient information can be expressed more simply, according to the present invention, as described in claim 4, in each of the wireless communication methods, the transmission path coefficient information generation procedure is the first. The level Aki of the received signal at the second communication device i corresponding to the pilot signal Pk is determined on the basis of the level of the pilot signal Pk transmitted from the communication device, and the pilot signal Pk from the first communication device is obtained. The delay time Tk of the reception timing of the corresponding reception signal in the second communication device i with respect to the transmission timing is obtained, and the level Ak and delay time Tk of the reception signal are the pilot signal Pk transmitted from the first communication device. And information indicating the relation between the pilot signal Pk received by the second communication device and the signal corresponding to the pilot signal Pk.
The transmission path coefficient information hki indicating the state of the transmission path formed by the antenna beam #k corresponding to the pilot signal Pk between the first communication device and the second communication device i based on
Can be configured to generate.

In this radio communication method, the transmission path coefficient information can be represented by two parameters, that is, the reception level of the received signal corresponding to each pilot signal and the delay time.

From the viewpoint of providing specific transmission path coefficient information, the present invention provides that the transmission path coefficient information generating procedure includes the pilot signal Pk.
Level Ak of the received signal at the second communication device i corresponding to
And its delay time Tk, hki = Ak · exp (−j · 2π · f · Tk) f: first communication device and second communication device formed by antenna beam #k according to the frequency of the pilot signal The transmission path coefficient information hki representing the state of the transmission path with respect to i can be obtained.

From the viewpoint of enabling higher quality communication when a plurality of transmission lines are formed by each antenna beam, the present invention provides each wireless communication as described in claim 6. In the method, the transmission path coefficient information generation procedure is performed by the pilot signal Pk in each second communication device i.
When a plurality of signals corresponding to the above are received, the reception level Aks of each signal is obtained with reference to the level of the pilot signal, and the second communication with respect to the transmission timing of the pilot signal from the first communication device is performed. The delay time Tks of each reception signal in the device is obtained, and the reception level Aks and delay time Tks of each reception signal in the second communication device i obtained as described above are transmitted from the first communication device. The transmission channel coefficient information may be generated based on the information indicating the relationship between the pilot signal Pk and the signal received by the second communication device i corresponding to the pilot signal. .

In the above case, from the viewpoint of providing concrete transmission channel coefficient information, the present invention provides the transmission channel coefficient information generating procedure in the wireless communication method as described in claim 7. , Using the level Aks of each received signal and its delay time Tks in the second communication device i corresponding to the pilot signal Pk,

[0025]

[Equation 4] n: number of signals corresponding to pilot signal Pk arriving at the second communication device (2 or more) Aks: sth reception level Tks: s of signal corresponding to pilot signal Pk arriving at the second communication device i Second, the delay time f of the signal corresponding to the pilot signal Pk arriving at the second communication device i: the first communication device and the second communication device i formed by the antenna beam #k according to the frequency of the pilot signal The transmission path coefficient information hki representing the state of the transmission path during the period can be obtained.

From the standpoint that the relationship between the received signal and the pilot signal at each second communication device can be expressed on a relative basis, the present invention provides each of the above-mentioned features. The wireless communication method has a reference signal transmission procedure of transmitting a reference signal from the first communication device before transmitting each pilot signal from the first communication device, and the pilot signal transmission procedure is the first communication. Transmitting each pilot signal from the device in a predetermined time relationship with the transmission timing of the reference signal, the transmission path coefficient information generation procedure,
When receiving the signal corresponding to the reference signal and the signal corresponding to each pilot signal in each second communication device, the reception level of the signal corresponding to the pilot signal is set to the reception level of the signal corresponding to the reference signal. The delay time of the reception timing of the signal corresponding to each pilot signal with respect to the reception timing of the signal corresponding to the reference signal is obtained as a reference, and the level and delay time of the reception signal corresponding to each pilot signal are obtained as described above. Information indicating a relationship between a pilot signal transmitted from the first communication device and a signal corresponding to the pilot signal received by the second communication device, and the transmission path coefficient information is generated based on the information. Can be configured as.

From the viewpoint that high quality communication becomes possible when the reference signal arrives at each second communication device through a plurality of transmission paths, the present invention is as set forth in claim 9. In the wireless communication method, the transmission path coefficient information generation procedure is such that, when the second communication device receives a plurality of signals corresponding to the reference signal at different timings, one signal from the plurality of signals is received. And determine the level of the received signal corresponding to each pilot signal with reference to the received level of the selected signal, and receive the received signal corresponding to each pilot signal with respect to the reception timing of the selected signal. It can be configured to determine the timing delay time.

When selecting one reception signal from the reception signals corresponding to the reference signal, even if the reception signal that arrives at the second communication device is selected first, the reception signal with the highest reception level is selected. Also, other received signals may be selected. The selection criterion can be set so that each second communication device can receive a higher quality signal.

From the viewpoint that the generation of the transmission channel coefficient information becomes simpler, the present invention provides the transmission channel coefficient information generating procedure in each wireless communication method as described in claim 11. When a plurality of signals corresponding to each pilot signal are received at different timings in the second communication device, it is possible to shift each received signal corresponding to each pilot signal on the time axis so that reception is performed at a predetermined same time. Having a combined reception signal generation procedure for generating a combined reception signal that is equalized and combined, and is configured to generate transmission path coefficient information based on information representing the relationship between each pilot signal and the corresponding combined reception signal. You can

From the viewpoint that it is possible to obtain a higher quality received signal in each second communication device, the present invention provides the above-mentioned combined received signal in the above-mentioned wireless communication method as described in claim 12. The generation procedure has a weight generation procedure for generating a weight for each reception signal corresponding to the pilot signal so that the reception quality of the pilot signal to be transmitted to the second communication device satisfies a predetermined condition, The received signals may be weighted and combined by using the weights together with the time equalization to generate a combined received signal.

In each of the above wireless communication methods, as described in claim 13, in the transmission path coefficient information generating procedure, the combined reception level of the combined reception signal is set to the pilot signal transmitted from the first communication device. Information representing the relationship with the signal corresponding to the pilot signal received by the second communication device, and based on this combined reception level and the predetermined same time used in the time equalization, the transmission path coefficient It can be configured to generate information.

In such a wireless communication method, the transmission path coefficient information can be easily obtained by using the same predetermined time determined in the wireless communication system composed of the first communication device and the plurality of second communication devices. Can be generated.

From the viewpoint of enabling higher quality communication, the present invention provides the radio communication method as described in claim 14, wherein the transmission path coefficient information generation procedure is performed for each antenna beam. Of the corresponding pilot signals, the pilot signal is selected based on the reception quality at each second communication device, and the transmission path is selected based on the information indicating the relationship between the selected pilot signal and the corresponding received signal. It can be configured to generate coefficient information.

In order to reduce the processing amount, according to the present invention, as described in claim 15, in the wireless communication method, the transmission path coefficient information generation procedure corresponds to each antenna beam #k. Of the pilot signals, a predetermined number (n) of pilot signals are selected based on the reception quality at each second communication device i, and the selected pilot signals Pk (1 to n) and their pilot signals Pk are selected. Based on the information indicating the relationship with the corresponding received signal, the state of the transmission line formed between the first communication device and the second communication device i is determined by the antenna beam #k corresponding to the pilot signal Pk. A transmission line coefficient element hki is obtained, and a transmission line coefficient matrix [H] in which the transmission line coefficient elements hki corresponding to the respective pilot signals Pk are concentrated in the diagonal region and the other elements are zero is generated as transmission line coefficient information. You It can be configured to.

When the number M of antenna beams formed by the first communication device is larger than the number N of the second communication devices, the transmission path coefficient information generation procedure as described in claim 16. Each antenna beam # from the first communication device
pilot signal transmitted at k (k = 1 to M) and each second communication device i corresponding to the pilot signal Pk
The transmission signal D1 from each antenna beam # 1 to #M based on the information indicating the relationship with the reception signal at (i = 1 to N)
-DM and received signals R1 to RN at the second communication devices 1 to N
[R] = [H] · [D] [R]: 1 × N matrix consisting of elements R1 to RN [D]: 1 × M matrix consisting of elements D1 to DM [H]: From element hki M × N matrix (k = 1 to M, i =
1 to N), a transmission channel coefficient matrix [H] is generated as transmission channel coefficient information, and the conversion operator calculation procedure is [T] = [H] · [Z] [Z]: N × M Matrix [T]: A conversion operator represented by a matrix [Z] defined by an N × N matrix in which components other than diagonal components are zero is calculated, and the signal conversion procedure is performed in each second communication. The signals [S] = S1 to SN to be transmitted to the devices 1 to N are transmitted by the respective antenna beams # 1 to #M according to [D] = [Z] · [S] [D] = D1 ~ DM, the above signal transmission procedure,
The signals D1 to DM obtained by the above conversion can be configured to be transmitted from each of the antenna beams # 1 to #M from the first communication device.

In such a wireless communication method, the received signals [R] = R1 to RN at the second communication devices 1 to N are Becomes Since the matrix [T] is an N × N matrix in which the components other than the diagonal components are zero, each received signal Ri is represented by Ri = Tii × Si. That is, the received signal Ri in each second communication device i is only the component of the signal Si to be transmitted to the second communication device i.

The conversion operator calculation procedure is, as described in claim 17, a reception signal R in each second communication device i.
In consideration of the condition that i becomes maximum, each element of the matrix [Z] that serves as the conversion operator can be calculated.

Further, the transmission path coefficient information generation procedure is such that, when the second communication device i receives the signal RiPk corresponding to each pilot signal Pk, the received signal is received. A first procedure of calculating each element hki (k = 1 to M) of the i-th row in the transmission path coefficient matrix [H] based on the information indicating the relationship between RiPk and the pilot signal Pk, and each second Second procedure for notifying each element hki of the above-mentioned i-th row to the first communication apparatus from the communication apparatus i, and the i-th row notified from each second communication apparatus i in the first communication apparatus. The above channel coefficient matrix [H] using each element hki
And a third step of generating

In order to reduce the processing amount, according to the present invention, as described in claim 19, in each of the wireless communication methods, the transmission path coefficient information generation procedure corresponds to each antenna beam #k. Of the selected pilot signals, a predetermined number (n) of pilot signals are selected based on the reception quality at each second communication device i, and the selected pilot signals Pk (k = 1 to n) and their pilots are selected. A transmission path formed between the first communication device and the second communication device i by the antenna beam #k corresponding to the pilot signal Pk based on the information indicating the relationship with the received signal corresponding to the signal Pk. Of the transmission path coefficient element hki representing the state of the transmission path coefficient hki corresponding to each pilot signal Pk is concentrated in the diagonal region, and the transmission path coefficient matrix [H] in which the other elements are zero is obtained. Raw as information It can be configured to.

From the viewpoint of enabling higher quality communication, the present invention provides an antenna pattern in each second communication device in each of the above-mentioned wireless communication methods as described in claim 20. Is adjusted to receive each pilot signal with a substantially omnidirectional antenna pattern, the pilot signal with the best reception quality is selected from the received pilot signals, and the reception quality of the selected pilot signal is The directivity of the antenna pattern may be adjusted so as to satisfy a predetermined condition, and the antenna pattern with the adjusted directivity may be used to perform the processing in the transmission path coefficient information generation procedure.

In order to solve the above first problem, the present invention provides, as described in claim 21, between a first communication device having a plurality of antennas and a plurality of second communication devices. In a wireless communication system that performs wireless communication, pilot signal transmission control means for transmitting a pilot signal corresponding to each antenna beam from a first communication device to a plurality of second communication devices by a plurality of antenna beams, It is formed by each antenna beam based on the information indicating the relationship between the pilot signal transmitted from each communication device by each antenna beam and the signal corresponding to the pilot signal received by each second communication device. And a signal to be transmitted to each second communication device, and transmission line coefficient information generating means for generating transmission line coefficient information indicating the state of the transmission line between the first communication device and the second communication device. When the transmission signal to be transmitted by each antenna beam obtained by conversion with the conversion operator is transmitted by each antenna beam, the received signal at each second communication device becomes the signal to be transmitted. A conversion operator calculation means for calculating the conversion operator based on the transmission path coefficient information, and a signal to be transmitted to each second communication device using the conversion operator should be transmitted by each antenna beam. It is configured to have signal conversion means for converting into a transmission signal, and signal transmission control means for transmitting the transmission signal obtained by the conversion from the first communication device with each antenna beam.

Further, from the viewpoint of providing a communication device which performs communication according to the above-mentioned wireless communication method, the present invention has a plurality of antennas and a plurality of partner communication as described in claim 41. In a communication device that wirelessly communicates with a device, a pilot signal transmitting means for transmitting a pilot signal corresponding to each antenna beam to a plurality of partner communication devices by a plurality of antenna beams, and after transmitting the pilot signal When receiving information representing the relationship between each pilot signal and its received signal from each partner communication device, between the communication device and each partner communication device formed by each antenna beam based on the information. And a signal to be transmitted to each partner communication device by a conversion operator. When the transmission signal to be transmitted by each antenna beam is transmitted by each antenna beam, the conversion operator is set so that the reception signal at each partner communication device becomes the signal to be transmitted. And a signal conversion means for converting a signal to be transmitted to each partner communication device into a transmission signal to be transmitted by each antenna beam by using the conversion operator, and the conversion operator. It is configured to have a signal transmitting unit that transmits the obtained transmission signal by each antenna beam.

Furthermore, from the viewpoint of providing a communication device that performs communication according to the above-described wireless communication method, the present invention, as set forth in claim 45, includes a predetermined communication device having a plurality of antennas. In a communication device that performs wireless communication between the two, when a pilot signal corresponding to each antenna beam is transmitted by a plurality of antenna beams from the predetermined communication device, each pilot signal and a reception signal corresponding to the pilot signal It is configured to have a first means for generating information indicating the relationship of 1 and a second means for notifying the predetermined communication device of the information.

[0044]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

The radio communication system according to the first embodiment of the present invention is configured, for example, as shown in FIG. The radio communication system according to the present embodiment is a mobile communication system that performs radio communication between a radio base station and a plurality of mobile stations.

In FIG. 1, the wireless base station 10 and a plurality of (N
The wireless communication is performed with the individual mobile stations 20 (1) to 20 (N). A plurality of wireless base stations 10 (M: M> N)
It has an antenna unit 13 having an antenna element and a multi-beam combining circuit 14. The multi-beam combining circuit 14 performs control for forming N antenna beams # 1 to #N for transmitting signals from the antenna unit 13 to the N mobile stations 20 (1) to 20 (N). .

Each antenna beam # 1 from the radio base station 10
The signals transmitted in ~ N are not the signals S themselves to be transmitted to each mobile station, but the signals S are the transfer functions (transmission path coefficient) between each antenna beam # 1 to #N and each mobile station. )
The signal D is converted by using the inverse function of. The transmitted signal D is generated as follows.

The transfer functions are used for the relationship between the signals D1 to DN transmitted by the antenna beams # 1 to #N and the received signals R1 to RN at the mobile stations 20 (1) to 20 (N). Similarly to the above-described formula (1),

[0049]

[Equation 5] It is expressed as. When these relationships are expressed in the form of a determinant, [R] = [H] · [D] (4).

Here, each mobile station 20 (1) to 20 (N)
The signal [S] to be transmitted to each antenna beam # 1 to
If the inverse function (inverse matrix) [H] ⁻¹ of the above transfer function (matrix) [H] is used as the conversion operator for converting into the signal [D] to be transmitted in #M, [D] = [H ] ^-1・ [S] …… (5)

Substituting equation (5) into equation (4) yields the following.

[0052] That is, [R] = [S], and each mobile station receives the desired signal [S] that is completely unaffected by interference.

Therefore, the signal [D] (obtained by multiplying the signal (desired signal) [S] to be transmitted to each mobile station by using the inverse function [H] ^-1 of the transfer function [H] as a conversion operator. (See equation (5)) from the radio base station 10 to each antenna beam #
The signal [R] received by each mobile station is transmitted from 1 to #N (the desired signal).
[S] itself. That is, the radio base station 10 includes the antenna beams # 1 to #N and the mobile stations 20 (1) to 20.
By obtaining the transfer function [H] between (N),
It becomes possible for each mobile station to transmit the signal D so that it can receive the signal S without the influence of interference.

Signal D transmitted from the radio base station 10
The transfer function (transmission path coefficient) required to generate (see equation (5)) can be easily defined as follows, for example.

For example, in the first model as shown in FIG. 2, the signal St (f) from the radio base station 10 (transmission station) is transmitted.
Is transmitted, the mobile station 20 (reception station) receives a signal Sr (f) corresponding to the transmission signal St (f) (f is a frequency).

In this case, the relationship between each signal St (f) and Sr (f) is generally represented by Sr (f) = h.St (f) (7).

The transmission signal St (f) and the reception signal Sr
The function h associating (f) can be a transfer function that depends on the state of the transmission path between the radio base station 10 and the mobile station 20.

When the transmission path between the radio base station 10 and the mobile station 20 is in sight, the number of reflections and diffractions is relatively small, and the frequency band of the signal is relatively narrow, It can be assumed that the shape of the signal does not change in the course of being transmitted. In this case, as shown in FIG. 2, the transmission signal S from the radio base station 10 at time t = 0.
When t (f) is transmitted, the reception level of the corresponding reception signal Sr (f) in the mobile station 20 is A of the transmission signal St (f).
(A <1), and the reception timing is delayed from the transmission timing (t = 0) by the delay time T. Then, the reception signal Sr represented on this frequency axis
(F) is a transmission signal St similarly represented on the frequency axis
(F) can be used to approximate as follows (for example, Morikita Shuppan "Modern communication line theory" p.23: S. Stein, JJ Jones).

Sr (f) ≈St (f) · A · exp (−j · 2π · f · T) (8) In the above formula (8), −j = √−1, A is the reception level,
T is the delay time.

From the equations (7) and (8), the transfer function h can be defined as follows: h = A · exp (−j · 2π · f · T) (9)

As shown in the equation (9), the transfer function h is
It can be calculated from the two parameters of the reception level A and the delay time T, and the state of the transmission path can be estimated relatively easily.

From such a theoretical consideration, when the pilot signal is transmitted from the radio base station 10, the reception level A of the signal corresponding to it at the mobile station 20 and the corresponding signal with respect to the transmission timing of the pilot signal By measuring the delay time T of the reception timing, it is possible to obtain the transfer function h (transmission path coefficient) which is a parameter indicating the state of the transmission path between the radio base station 10 and the mobile station 20.

The reception level and the delay time can be measured, for example, as follows.

1) The transmitter of the radio base station 10 and the mobile station 20
Synchronize with the receiver of.

2) In this state, the radio base station 10 transmits, for example, an M-sequence pilot signal.

3) The mobile station 20 receives a signal corresponding to the pilot signal.

In the mobile station 20, the relative reception of the signal corresponding to the delay time T and the transmitted pilot signal is obtained by taking the correlation between the known pilot signal stored in the internal memory and the received signal. Get level A.

The reception level A is generally a real number, but it can be measured as a vector containing the phase θ. In this case, the reception level A (relative value)
Is represented by A = | A | exp (θj).

Thus, when the reception level A is measured as a vector as described above, the transfer function h is h = A · exp (−j · 2π · f · T) = | A | exp (θ * J) * exp (-j * 2 ** f * T) = | A | exp [-j * (2 ** f * T- (theta))] ... (10).

In this way, when the reception level A is measured as a vector, the state of the transmission line can be estimated more accurately by the transfer function h represented by it.

From the above equation (10), when the reception level A is measured as a real number, its phase θ should be measured in the form included in the delay time T (2π · f · T−θ). become.

Next, the case of obtaining the transfer function h in the second model as shown in FIG. 3 will be described.

In the model shown in FIG. 3, the signal transmitted from the radio base station 10 (transmitting station) in the mobile communication system is transmitted to the mobile station 20 via a plurality of paths (for example, three paths).
It represents the state of arrival at the (reception station).

In such a model, when the signal St (f) is transmitted from the radio base station 10, the signal St (f) is transmitted.
Arrives at the mobile station 20 through the path p1 without being reflected or diffracted by the building. The signal St (f) is
The mobile station 2 passes through the path p2 reflected by the building 30.
It reaches 0. Further, the signal St (f) arrives at the mobile station 20 through the path p3 reflected by another building 40.

When signals are observed on the time axis in such a situation, as shown in FIG.
The signal St (f) transmitted from the radio base station 10 at the time t = 0 arrives at the mobile station 20 with different delay times T1, T2, and T3 due to the difference in the lengths of 2 and p3.
Further, the reception level of the signal that arrives at the mobile station 20 with each delay time is A1 times (A1) times that of the transmitted signal St (f).
1 <1), A2 times (A2 <2), and A3 times (A3 <1). In this case, ignoring the interference between the paths, the received signal Sr (f) at the mobile station 20 will have the paths p1, p2,
It is considered to be a superposition of signals arriving at the mobile station 20 through p3. Then, the relationship between the transmission / reception signals represented on the frequency axis in each path can be approximated by the above equations (8) and (9). As a result, the mobile station 2
The received signal Sr (f) at 0 can be expressed as:

Sr (f) = St (f) .h = St (f) .h1 + St (f) .h2 + St (f) .h3.apprxeq.St (f) .A1.exp (-j.2.pi.f.T1) + St (f) · A2 · exp (−j · 2π · f · T2) + St (f) · A3 · exp (−j · 2π · f · T3) = St (f) · {A1 · exp (-j · 2π · f · T1) + A2 · exp (-j · 2π · f · T2) + A3 · exp (-j · 2π · f · T3)} (11) A1: A signal arriving at the mobile station through the path p1. Reception level A2: reception level of a signal arriving at a mobile station through path p2: reception level A3 of a signal arriving at a mobile station through path p3: delay of a signal arriving at a mobile station through path p1 Time T2: Delay time of signal arriving at mobile station via path p2 T3: Delay time of signal arriving at mobile station via path p3 h1: coefficient dependent on transmission path state of path p1 h2: coefficient dependent on transmission path state of path p2 h3: coefficient dependent on transmission path state of path p3 Therefore, between the radio base station 10 and the mobile station 20 The transfer function h representing the state of the transmission line is: h = A1 · exp (−j · 2π · f · T1) + A2 · exp (−j · 2π · f · T2) + A3 · exp (−j · 2π · f · T3) can be represented by (12).

This transfer function h can be expressed in the form of h = A · exp (−j · 2π · f · T) (13). In the above equation (13), A is a composite complex number or real number reception level,
T is a synthetic delay time.

From the theoretical consideration as described above, when the pilot signal is transmitted from the radio base station 10, the mobile station 2
Between the radio base station 10 and the mobile station 20 by measuring the reception level of signals received at different timings of 0 and the delay time of the reception timing of each signal corresponding to the transmission timing of the pilot signal. It is possible to obtain the transfer function h (transmission path coefficient) that represents the state of the transmission path.
The reception level and delay time of each signal can be measured by the same method as the above-mentioned method.

Further, the case of obtaining the transfer function h in the third model as shown in FIG. 4 will be described.

In the first model and the second model described above, in order to measure the signal delay time, the radio base station 10
Must be accurately synchronized with the mobile station 20.
In the following model, by transmitting a reference signal and expressing the reception timing and the reception level of the pilot signal transmitted on the basis of the reception timing and the reception level of the reference signal, the above-mentioned radio base station 10 (transmission It is not necessary to synchronize the station) with the mobile station 20 (reception station).

In the third model shown in FIG. 4, the radio base station 10 includes a reference antenna 15 and communication antennas # 1 to # 1.
#M. N mobile stations 20 (1) -20
(N) is in the area where the signal from the wireless base station 10 can be received.

The radio base station 10 transmits a reference signal (reference signal) Rs as shown in FIG. 5A from the reference antenna 15 at a predetermined timing (t = 0), and
At the same timing (t = 0) as the reference signal Rs from each antenna #k (k = 1 to M), for example, a pilot signal S as shown in FIG. 5C is transmitted. The pilot signal S differs for each antenna # 1 to #M.

When the reference signal Rs is transmitted from the reference antenna 15 of the radio base station 10 as described above, the reference signal Rs passes through various paths, as described above, to each mobile station,
For example, it arrives at mobile station 20 (1). As a result, the mobile station 20 (1) receives a plurality of signals corresponding to the reference signal Rs at different timings, for example, as shown in FIG. 5B, due to the difference in the path through which the reference signal Rs passes.

When the pilot signal S is transmitted from the antenna #k of the radio base station 10 as described above, the pilot signal S also travels through various paths to each mobile station, for example, the mobile station 20 (1). Come to. As a result, the mobile station 2
0 (1) receives a plurality of signals corresponding to the pilot signal S at different timings, for example, as shown in FIG. 5D, due to the difference in the path through which the pilot signal S passes.

The mobile station 20 (1) selects a reference signal from a plurality of signals (reception profiles) corresponding to the reference signal Rs received at different timings as described above. For example, the signal with the highest reception level, or
The signal received at the earliest timing is selected as the reference signal. Generally, the reception level of the signal arriving at the mobile station 20 (1) at the earliest timing is the highest, but if the signal arriving at the earliest timing is different from the signal having the highest reception level, it will be described later in the system. It is set in advance to select the one that can obtain a good result by such processing.

When a reference signal is selected from a plurality of signals corresponding to the reference signal Rs received at different timings in this way, the mobile station 20 (1) receives the reference signal reception timing (reference With reference to the timing) and the reception level (reference level), the delay time and the reception level of the reception timing of each of the plurality of signals corresponding to the pilot signal S received at the different timings are calculated. In the example shown in FIG. 5, the mobile station 20 (1)
Is the delay time T1, T2 of the reception timing of the two signals corresponding to the pilot signal S and the reception levels A1, A
Calculate 2.

When the mobile station 20 (1) thus calculates the delay times T1 and T2 and the reception levels A1 and A2 of the signals corresponding to the pilot signal S, the antenna of the radio base station 10 is calculated based on these information. The transfer function hk1 representing the state of the transmission line between #k and the mobile station 20 (1) is given by the above equation (1)
Calculate according to 2). As a result, the transfer function hk1
Is calculated as follows: hk1 = A1 · exp (−j · 2π · f · T1) + A2 · exp (−j · 2π · f · T2) (14)

This transfer function hk1 can also be expressed in the form of hk1 = Ak1 · exp (−j · 2π · f · Tk1) (15) as in the above equation (13).

As described above, the reference signal Rs is transmitted from the reference antenna 13 and each antenna # 1 to #M is transmitted.
, And a transfer function h11, h21, ..., h representing the state of the transmission path between each antenna and the mobile station 20 (1) in accordance with the procedure described above.
.., hM1 are obtained at the mobile station 20 (1). Also,
Similarly, the other mobile stations 20 (i) (i = 2, 3, ... N)
Transfer function h between each antenna and the mobile station 20 (i)
Get 1i, h2i, ..., hki, ... hMi.

The transfer function hki obtained by each mobile station 20 (i) is calculated by using each antenna #k and each mobile station based on the state of the transmission path between each mobile station 20 (i) and the reference antenna 15. 20 (i) shows the relative state of the transmission line.

The reference antenna 15 installed in the radio base station 10 needs to be able to receive the reference signal Rs in good condition in all the mobile stations 20 (1) to 20 (N), so it is as high as possible. It is preferable to devise a non-directional radio wave radiation pattern.

Further, in the above model, the reference signal Rs and the pilot signal S are transmitted from the radio base station 10 at the same timing, but the respective signals may be transmitted at different timings. In this case, the difference between the transmission timings may be known in advance in the system (radio base station 10 and each mobile station 20 (i)).

Further, although the reference signal Rs is transmitted from the reference antenna 15 in the above model, any one of the antennas # 1 to #M for transmitting a normal signal may also be used as the reference antenna. Is also possible.

As described using the first model to the third model, the reception level A and the delay time of the pilot signal transmitted from each antenna (antenna beam) # 1 to #N of the radio base station 10 T to each mobile station 20 (1)-
By measuring at 20 (N), each antenna # 1
The transfer function h between #N and each mobile station 20 (1) to 20 (N) can be calculated according to the equation (15).

Therefore, in the system as shown in FIG. 1, each mobile station 20 (i) (i = 1 to 2) transmits on each antenna beam #k (k = 1 to N) of the radio base station 10. The coefficient Aki relating to the reception level of the pilot signal to be generated and the coefficient Tki relating to its delay time are obtained, and the respective coefficients Aki,
Tki is notified to the radio base station 10. For example, the mobile station 20
(1) is (A11, T11), (A21, T21), ..., (A
k1, Tk1), ..., (AN1, TN1) are notified, and the mobile station 20
(2) is (A12, T12), (A22, T22), ..., (A
k2, Tk2), ..., (A1N, T1N) is notified, and the mobile station 20
(N) is (A1N, T1N), (A2N, T2N), ..., (A
kN, TkN), ..., (ANN, TNN) are notified.

Upon receiving this notification, the radio base station 10 receives the coefficients Aki and T from the mobile stations 20 (1) to 20 (N).
Using ki, each antenna beam # 1 to
The transfer function h between #N and each of the radio base stations 20 (1) to 20 (N) is calculated. Then, the radio base station 10 calculates an inverse function (inverse matrix) [H] ⁻¹ from the transfer function [H] (matrix expression) obtained from each of the mobile stations 20 (1) to 20 (N), and The signal D to be transmitted to each of the base stations 20 (1) to 20 (N) is generated according to the equation (5) using the inverse function [H] ⁻¹ .

As described above, the radio base station 10 uses the antenna beams # 1 to #N for the mobile stations 20 (1) to 20 (N).
When the signal D is transmitted to (N), each mobile station 20
(1) to 20 (N) can receive the desired signal S without any influence of interference (see the equation (6)).

As described in the third model, when deriving the transfer function, the absolute value is not always required, and even if the transfer function representing the relative state as described above is used, (6) is established. That is, if all the radio waves arriving at one mobile station are measured with the same standard,
According to the transfer function obtained from the measurement result, the above equation (6)
Holds.

Next, a second embodiment will be described.

In the above-described first embodiment, in order to obtain the transfer function at the radio base station 10, each mobile station 20 (1)
˜20 (N) notifies the radio base station 10 of the coefficient Aki related to the reception level of the pilot signal corresponding to each antenna beam and the coefficient Tki related to the delay time.
In this embodiment, the amount of information to be notified from each mobile station in order to obtain the transfer function at the radio base station 10 can be further reduced. Further, in this embodiment, the quality of the received signal at each mobile station is improved.

A radio communication system (mobile communication system) according to the second embodiment of the present invention is configured, for example, as shown in FIG.

In FIG. 6, as in the mobile communication system shown in FIG. 1, N mobile stations 20 are connected from the radio base station 10.
N antenna beams # 1 to #N for transmitting signals for (1) to 20 (N) are multi-beam combining circuit 1
Formed by 4. Each mobile station 20 (1) -20
(N) has a time equalizer / synthesizer 25 as described later. By the processing in the time equalization synthesizer 25, the amount of information representing the transfer function h is reduced.

Also in the system according to the present embodiment,
The radio base station 10 acquires the transfer function [H] between each antenna beam # 1 to #N and the mobile station 20 (1) to 20 (N), and its inverse function (inverse matrix) [H] ⁻ Equation ¹ using ¹
Signal [D] to be transmitted to each of the mobile stations 20 (1) to 20 (N) according to.

Consider the fourth model shown in FIG.

In this fourth model, the radio base station 10
When a signal St (f) is transmitted from one antenna beam by the antenna, the signal S (f) is transmitted in the same manner as the second model shown in FIG.
Due to the difference in the paths p1, p2, p3 through which t (f) propagates, the signal St (f) has different delay times Ta, T
It arrives at the mobile station 20 with b and Tc. In addition, the mobile station 2
The received level of each signal that has reached 0 is also the transmitted signal S
It becomes Aa, Ab, and Ac times t (f).

In this case, similar to the second model, the partial transfer functions ha (corresponding to the path p1), h corresponding to each path, h
b (corresponding to path p2) and hc (corresponding to path p3) are: ha = Aa · exp (−j · 2π · f · Ta) hb = Ab · exp (−j · 2π · f · Tb) hc = Ac * Exp (-j * 2 ** f * Tc) ... It is represented like (16).

In the second model, the transmission line function h is represented by the simple sum of these partial transfer functions ha, hb, hc (see equation (12)). However, expressing the transfer function h by the simple sum of the partial transfer functions corresponding to each of these paths does not necessarily faithfully represent the state of the transmission path between the radio base station 10 and the mobile station 20. Therefore, even if the signal D according to the above equation (5) is transmitted from the radio base station 10, the transmission quality (SN) for the desired signal at the mobile station 20 is obtained.
Does not always improve as expected.

Therefore, paying attention to the transmission quality (SN) of the desired signal in the mobile station 20, each partial transfer function ha, hb, hc is multiplied by a weight so that the transmission quality (SN) becomes maximum. To obtain the transfer function h. At the same time, the delay times Ta, Tb, Tc are changed according to the difference of each path.
The respective signal waves received by are time-equalized and combined by the time equalizer / combiner 25 so that they are received at the same delay time Tx.

As a result, the transfer function h is h = W1a · Aa · exp (−j · 2π · f · (Ta + Tea)) + W1b · Ab · exp (−j · 2π · f · (Tb + Teb)) + W1c · Ac · exp (−j · 2π · f · (Tc + Tec)) = A · exp (−j · 2π · f · Tx) (17) In equation (17), W1a, W1b,
W1c is a weight selected under the condition that the quality of the signal arriving through each path of the transmission path is the best. Further, Tea, Teb, and Tec are adjustment coefficients for performing time equalization so that the delay time in each path becomes Tx.

With such a transfer function h, the transmission signal St (f) from the radio base station 10 and a plurality (for example, three) of signal waves in the mobile station 20 are time-equalized to obtain a single signal. The relationship with the received signal S'r (f) which becomes a wave is expressed by S'r (f) = St (f) · A · exp (-j · 2π · f · Tx) (18) (See FIG. 7).

By performing the weight adjustment and the time equalization / combining process as described above in the mobile station 20, the transfer function h between the antenna beam from the radio base station 10 and the mobile station 20 is uniquely determined. It Then, if the time coefficient Tx related to the time equalization is a known value in the system, the mobile station 20 determines the coefficient A related to the reception level considering the weight.
By notifying the wireless base station 10 of (see Expression (17)), the wireless base station 10 can obtain the transfer function h according to the above Expression (17).

Next, the case of obtaining the transfer function h in the fifth model as shown in FIG. 8 will be described. In this fifth model, the signal St (f) is transmitted from the radio base station 10 to the mobile station 20 using a plurality (two) of antenna beams (# 1 (B1) and # 2 (B2)).

In the case of transmitting a signal by such a multi-beam, it can be considered that the phase centers of all the antenna beams are at the same place, for example, at the centers of a plurality of antenna elements forming those antenna beams. it can. Therefore, if the radio waves coming from any antenna beam are observed at a sufficiently long distance, it can be considered that the radio waves are emitted from the same point. This means that, as shown in FIG. 8, even if the arriving waves are from different antenna beams, their delay profiles (temporal position of each arriving wave) are the same. That is, the signal waves transmitted by all the antenna beams reach the mobile station 20 through the paths having the same reflection, diffraction, etc., and the delay time pattern of the delayed waves corresponding to each antenna beam ( The delay profile) is the same.

From this, as shown in FIG. 8, the transfer function h between the antenna beam # 1 (B1) and the mobile station 20.
11 partial transfer function groups h11ha, h11b, h11c, and the transfer function h between the antenna beam # 2 (B2) and the mobile station 20.
The 21 partial transfer function groups h21a, h21b, and h21c are expressed as follows.

H11a = A1a · exp (−j · 2π · f · Ta) h11b = A1b · exp (−j · 2π · f · Tb) h11c = A1c · exp (−j · 2π · f · Tc) ( 19) h21a = A2a · exp (−j · 2π · f · Ta) h21b = A2b · exp (−j · 2π · f · Tb) h21c = A2c · exp (−j · 2π · f · Tc) (20) ) As is clear from the above equations (19) and (20), the delay times Ta and T appearing in the exp (...) portion of each partial transfer function.
b and Tc are the same for the two transfer functions h11 and h21. This means that the same operation (adjustment) in the time direction may be performed when the two transfer functions are time-equalized, and it is not necessary to have a time coefficient for each antenna beam.

Further, in this system, for example, the radio base station 1
It is necessary for any mobile station 20 (1) to correspond to antenna beam # 1 (B1) from 0, and signals other than the signal to be transmitted there must be completely lost at the mobile station 20 (1). is there. Therefore, assuming that the antenna beam # 1 includes a signal to be transmitted to the mobile station 20 (1),
As described above, the weight of each partial transfer function may be determined under the condition that the signal quality (SN) is maximized. Therefore, the transfer function in the transmission line containing the desired signal is determined as follows.

H11 = W1a · A1a · exp (−j · 2π · f · (Ta + Tea)) + W1b · A1b · exp (−j · 2π · f · (Tb + Teb)) + W1c · A1c · exp (−j / 2π ·) f · (Tc + Tec)) (21) In the above equation (21), W1a, W1b, and W1c are weights selected under the condition that the quality of the signal passing through the transmission path of h11 is the best. . Also, Tea, Te
b and Tec are coefficients for time equalization so that the delay time in each path becomes the same value Tx.

Whether or not the desired signal quality, which is the condition for determining the weight, is the best is determined based on whether or not the signal quality (SN) satisfies a predetermined condition. Will be judged.

On the other hand, since the transmission line of h21 is a transmission line to which an interference signal arrives, any partial transfer function may be combined. Therefore, the transfer function h21 uses the same weight as in equation (21), It is expressed as.

H21 = W1a · A2a · exp (−j · 2π · f · (Ta + Tea)) + W1b · A2b · exp (−j · 2π · f · (Ta + Teb)) + W1c · A2c · exp (−j · 2π ·) f · (Tc + Tec)) (22) In the above formula (22), W1a, W1b, and W1c are expressed by the formula (2)
It is equal to those of 1). Further, the delay time (Ta, Tb, Tc) in the term of each arriving wave is similar to that in the case of antenna beam # 1, so the coefficients Tea, T for time equalization are used.
eb and Tec may be the same as those in equation (21).

From the above equations (21) and (22), the transfer functions h11 and h21 corresponding to the antenna beams # 1 and # 2 are obtained.
Is obtained as follows.

H11 = A1 · exp (−j · 2π · f · Tx) h21 = A2 · exp (−j · 2π · f · Tx) (23) As described above, a plurality of paths are formed by reflection or diffraction. When the transmission signal St (f) is transmitted therethrough to the mobile station 20, the transfer functions h11 and h21 corresponding to each antenna beam are expressed by a single term by providing the mobile station 20 with a time equalization combiner 25. To be done. Further, each transfer function h11 represented in this way,
The difference of h21 is only the coefficients A1 and A2 related to the reception level (combined reception level) considering the weight, and the delay time Tx after time equalization is the same. That is, antenna beam #
The operation of the time equalizer / combiner 25 in each mobile station for 1 and antenna beam # 2 is the same, and the weights may be the same.

Therefore, the mobile station 20 has its coefficient A1,
By notifying A2 to the wireless base station 10, the wireless base station 10 can obtain the transfer functions h11 and h21 according to the above equation (23).

In the system shown in FIG. 6, each mobile station 2
The pilot signals addressed to 0 (1) to 20 (N) are transmitted from the radio base station 10 by multi-beams (# 1 to #N), and each mobile station 20 (1) to 20 (N) has the above-mentioned configuration. Perform processing (weight adjustment, time equalization processing, etc.). And
Each mobile station 20 (i) (i = 1 to N) has a coefficient A corresponding to each antenna beam # 1 to #N obtained as a result of the above processing.
1i, A2i, ..., ANi (combined reception level) are transmitted to the radio base station 1
Notify 0. The radio base station 10 uses each mobile station 20 (i)
, HNi (i = 1 to N) are calculated according to the equation (23) using the coefficient notified from the transfer function between all the antenna beams and all the mobile stations ( Matrix) [H] is obtained as follows.

[0125]

[Equation 6] The system shown in FIG. 6 will be described in more detail. In addition,
In the above description, the transmission line between each antenna beam and the mobile station is represented by a transfer function. However, in actual processing, by dividing the band and time into fine parts, the transfer function in each section (time, band) is Can be regarded as one coefficient (transmission path coefficient). The transfer function can be represented by this set of transmission path coefficients. Therefore, in the following description,
The above transfer function is treated as a transmission path coefficient.

The downlink system of the radio base station 10 shown in FIG. 6 is configured as shown in FIG. 9, for example.

In FIG. 9, the radio base station 10 has an antenna unit 13 having M antenna elements and a multi-beam combining circuit 14, and also has M system signal processing units (1 to M). . Each signal processing unit (i = 1 to 1
M) is an up / down converter / shared device 101
(I), demodulator 102 (i), modulator 103 (i), channel coefficient receiver 104 (i), beam identification signal transmitter 1
05 (i) and a data transmission unit 106 (i).

Also, the radio base station 10 is the mobile station 20.
(1) to 20 (N), an information generation unit 107 that generates information S1 to SN to be transmitted, transfer coefficient matrix [H] (equation (24)
Inverse matrix calculation unit 108 for generating the inverse matrix [H] ⁻¹ of
Also, it has a transmission signal calculator 109 for calculating transmission signals D1 to DN to be transmitted to the mobile stations 20 (1) to 20 (N). The transmission signal calculation unit 109 includes an information generation unit 10
Using the information S1 to SN generated in 7 to be transmitted to the mobile stations 20 (1) to 20 (N) and the inverse matrix [H] ^-1 obtained by the inverse matrix calculation unit 108, Transmission signals D1 to DN for the mobile stations 20 (1) to 20 (N) are generated according to the above equation (5).

The coefficient Aki (transmission path coefficient hki) from the mobile station 20 (i) received by each antenna beam (#k) is received.
Corresponding to the mobile station 20 (i) via the multi-beam combining circuit 14.
Is supplied to. In the signal processing unit (i), the coefficient Aki is the up / down converter / shared device 101.
(I) is supplied to the transmission path coefficient receiving unit 104 (i) via the demodulation unit 102 (i). The transmission line coefficient receiving unit 104 calculates the transmission line coefficient hki according to the equation (23) using the supplied coefficient Aki. Then, the transmission path coefficient hki is supplied to the inverse matrix calculation unit 108. The inverse matrix calculation unit 108 includes the transfer function reception unit 104 of each signal processing unit (i).
The coefficients A1i, A2i, ..., Aki, ...
A channel coefficient matrix [H] represented by equation (24) is created using ANi, and further, an inverse matrix [H] ⁻¹ of the channel coefficient matrix [H] is created.

The beam identification signal transmitting section 105 (i) in each signal processing section (i) generates a predetermined identification signal corresponding to each antenna beam (#i), and the identification signal will be described later. It outputs as a pilot signal. This identification signal is supplied to the multi-beam combining circuit 14 via the demodulation unit 102 (i) and the up / down converter / shared device 101 (i), and the corresponding antenna beam (#
Sent in i). The identification signal transmitted by this antenna beam (#i) is transmitted to each of the mobile stations 20 (1) to 20 (20).
In (N), it is used to measure the transmission path coefficient corresponding to the antenna beam (#i).

The transmission signal Di for each mobile station 20 (i) obtained by the transmission signal calculation unit 109 as described above is
The data transmission unit 106 in the corresponding signal processing unit (i)
The transmission signal Di supplied to (i) and output from the data transmission unit 106 (i) is sent to the multi-beam combining circuit 14 via the modulation unit 103 (i) and the up / down converter / shared device 101 (i). Supplied. Then, the transmission signal Di is transmitted to the mobile station 20 by the antenna beam (#i).
It is transmitted from the radio base station 10 as a signal addressed to (i).

On the other hand, the downlink system of each mobile station 20 (i) is constructed, for example, as shown in FIG.

In FIG. 10, the mobile station 20 (i) has an up / down converter / shared device 201 and a modulator 20.
2, a demodulation unit 203, a transmission path coefficient transmission unit 204, an arithmetic processing unit 205, and a time equalization / synthesis circuit 25. The time equalizing / synthesizing unit 25 includes a time / weight adjusting unit 25a.
And a time coefficient / weight memory 25b.

In the mobile station 20 (i), the radio base station 10
Identification signal (pilot signal) of each antenna beam from
When the received wave corresponding to is received, the received wave (see Sr (f) shown in FIG. 8) is supplied to the time equalization synthesizing circuit 25 via the demodulation unit 203. This time equalization synthesis circuit 2
In No. 5, the time / weight adjusting unit 25a performs time equalization processing based on the reception timing of each received wave, and uses the weight so that the SN (quality) of the received wave with the maximum signal power becomes maximum. Combined signal (S'r shown in FIG. 8
(See (f)). Adjustment time coefficient obtained by this time equalization processing (see Tea, Teb, Tec shown in FIG. 8)
And the weights (see W1a, W1b, W1c shown in FIG. 8)
Is stored in the time coefficient / weight memory 25b.

The arithmetic processing unit 205 includes the time equalization / synthesis circuit 2
The synthesized signal (see S'r (f) shown in FIG. 8) generated in 5 is compared with the known antenna beam identification signal (pilot signal) to calculate the transmission path coefficient. In this example, since the transmission line coefficient hki can be reproduced by the coefficient Aki related to the reception level, the coefficient related to the relative reception level of the combined signal with respect to the signal level of the identification signal (A1, shown in FIG. 8, A2) is calculated.

The coefficient Aki related to the reception level is transmitted from the transmission path coefficient transmission section 204 to the radio base station 10 via the modulation section 202 and the up / down converter / shared device 201.

When the mobile station 20 (i) receives an actual data (eg packet) signal from the radio base station 10, the received signal is transmitted to the up / down converter / shared device 101 and the demodulation unit 203. It is supplied to the time / weight adjusting unit 25a of the time equalizing / synthesizing circuit 25 via the.
The time / weight adjusting unit 25a performs a combining process using the weight and the adjusted time coefficient stored in the time coefficient / weight memory 25b. The signal (see S'r (f) shown in FIG. 8) obtained by the synthesis processing is processed (data display, voice output, etc.) by the mobile station 20 (i) as a final received signal (output). It

From the theoretical consideration as described above (see the equations (5) and (6)), when the mobile station 20 (i) receives the actual data signal, the received signal has no interference. Although it should not be included, the interference component may not be completely eliminated due to measurement error or the like. Therefore, the time equalization synthesizing circuit 25 finely adjusts the time coefficient and the weight so that the SN (quality) of the desired signal is maximized even when the actual data signal is received.

The time / weight adjusting unit 25a is constructed, for example, as shown in FIG. In this example, time equalization processing is performed by a RAKE reception method.

In FIG. 11, the time / weight adjusting unit 25a is provided with a synthesis control unit 251 and a plurality of delay / wait circuits 252 (1) to 252 connected in parallel with each other.
Have (K). Each delay / wait circuit 252 (j)
Has a delay circuit (τj) and a weight multiplication circuit (W).

The synthesis control section 215 uses a number of delay / wait circuits 252 for the input signals so that delay characteristics such that a plurality of time-shifted signal waves included in the input signals coincide with each other in time are obtained. (1) to 252 (L). Further, the synthesis control unit 215 causes the delay / wait circuits 252 (1) to 252 (L) that process the input signal.
Of the weight multiplication circuit (W) of SN of the desired signal
Is controlled to be maximum. As a result, from the time / weight adjusting unit 25a, a combined signal that has been subjected to time equalization combining processing and weight adjustment with respect to an input signal including a plurality of signal waves (see S'r (f) shown in FIG. 8). Is output.

The time / weight adjusting unit 25a may be configured as shown in FIG. 12, for example. This example has a transversal filter configuration.

In FIG. 12, the time / weight adjustment unit 25a has a combination control unit 253 and a plurality of delay circuits 254 (1) to 254 (J) connected in series. The synthesizing control unit 253 uses each delay circuit 254.
Weight circuits (W1) to (WJ) for multiplying the outputs from (1) to 254 (J) by weights, and for connecting the outputs of the respective weight circuits (W1) to (WJ) to an output line. It has switches SW1 to SWJ. And
The synthesis control unit 254 obtains a delay characteristic such that a plurality of time-shifted signal waves included in the input signal coincide with each other in time, and obtains a weight that maximizes SN of a desired signal. ON / OFF control of each switch SW is performed as described above.

FIG. 13 shows the principle of the time equalization processing in the time / weight adjusting unit 25a having the configuration shown in FIG.

In FIG. 13, the signal waves a and b arriving at the delay times T1 and T2 are delayed by T1 by turning on the switch SWh and the signal waves a and b are turned on by the switch SWg. By T2
Delay only. As a result, the signal wave a output from the switch SWh and the signal wave b output from the switch SWg match in time. Then, the composite wave c is taken out. The signal wave a is multiplied by the weight W1 and the signal wave b is multiplied by the weight W2 so that the SN of the desired signal becomes maximum during the combination.

The principle of the time equalization processing in the time / weight adjusting unit 25a having the configuration shown in FIG. 11 is substantially the same as that described above.

Configuration as described above (FIG. 6, FIG. 9, FIG. 10)
The format of the signal transmitted from the radio base station 10 to each of the mobile stations 20 (1) to 20 (2) in the mobile communication system is as shown in FIG. 14, for example.

In FIG. 14, the signal is composed in packet units, and each packet is composed of each real data (DATA), a synchronization bit (Sync) added before it, and a pilot signal (PILOT). . The actual data (DATA) is the signal S to be transmitted to the mobile station, which is generated by the information generation unit 107 described above, and the pilot signal (PILOT) corresponds to each antenna beam formed in the radio base station 10. Beam identification signal.

The radio base station 10 calculates the transmission path coefficient based on the coefficient notified from each mobile station after transmitting the pilot signal (PILOT) while synchronizing with the synchronization bit (Sync), and calculates the transmission path coefficient. A matrix [H] and its inverse matrix [H] ⁻¹ are created. Then, at the transmission timing of the actual data (DATA), a signal obtained by multiplying the actual data for each mobile station by the above inverse matrix (see the above equation (5)) is transmitted.

Furthermore, the processing in the radio base station 10 and each mobile station which perform communication in the signal format as described above is performed, for example, according to the procedure shown in FIG.

In FIG. 15, in the mobile station 20 (i),
First, the delay time set in the time equalization synthesis circuit 25 is initialized (delay time = 0) (S201). After that, when the radio base station 10 transmits a pilot signal (PILOT) with each antenna beam # 1 to #N (S101),
The mobile station 20 receives these pilot signals (PILOT) (S202).

The mobile station 20 (i) detects the pilot signal (antenna beam number) Pk having the maximum received power among the received pilot signals (PILOT) (S20).
3), SN (quality) of the pilot signal (PILOT) Pk
Time equalization synthesis processing is performed so that
4). The time coefficient and weight described above are determined by this time equalization combining process (see FIGS. 8 and 13). The determined time coefficient and weight are stored in the time coefficient / weight memory 25b (S205).

The mobile station 20 (i) then compares the composite signal (see signal wave c in FIG. 13) thus obtained by the time equalization / combination processing with the known pilot signal,
A coefficient Aki (corresponding to the transmission path coefficient hki) corresponding to the relative reception level of the combined signal with respect to the pilot signal is calculated (S206). Then, the obtained coefficient A1i,
, Aki, ..., ANi are transmitted to the wireless base station 10 (S207).

The radio base station 10 is connected to the base station 2 as described above.
0 (i) and the coefficients A1i, A2 transmitted from other base stations
When i, ..., ANi, etc. are received (S102), the above equation (2)
Calculate the transmission coefficients h1i, h2i, ..., hNi according to 3),
The transmission line indicated by the above equation [24] with the transmission line coefficient hki
A coefficient matrix [H] is generated. And its inverse matrix [H]
^-1Is calculated (S103). Then, the wireless base station 10
At the transmission timing of the actual data (DATA),
Signal to be transmitted to each mobile station corresponding to actual data [S]
(S1 to SN) the above inverse matrix [H]^-1Multiply by (expression
(Refer to (5)) Transmission signal [D] (D1 to D) addressed to each mobile station
N) is generated (S104). The wireless base station 10
Antenna beam corresponding to transmission signal [D] (D1 to DN)
It transmits by # 1- # N (S105).

The mobile station 2 that has transmitted the coefficient Aki as described above.
0 (i) receives the signal waves corresponding to D1 to DN transmitted from the radio base station 10, and performs time equalization processing using the time coefficient and weight stored in the time coefficient / weight memory 25a ( S208). Then, each transmission signal D
Mobile station 20 (i) of the combined signal corresponding to 1 to DN
SN (quality) of signal (desired signal) Si to be transmitted to
The time coefficient and the weight are finely adjusted so as to maximize (S209). A signal Ri (= D1h1i + D2h2i + ... + DNhNi) is obtained by such time equalization processing (S210). This signal is transmitted from the mobile station 20 according to the above-mentioned theoretical consideration (see the above equations (5) and (6)).
(I) becomes the signal Si to be received (S211). That is, the mobile station 20 (i) can receive the signal SI generated by the radio base station 10 as a signal to be transmitted to the mobile station 20 (i) without interference.

The radio base station 10 successively receives signals from other mobile stations, receives new communication start and end requests, and always generates the latest transmission channel coefficient matrix (S).
106-S108).

Next, a third embodiment of the present invention will be described.

In each of the above-mentioned embodiments, each mobile station
Transmission channel coefficients hki for all antenna beams (coefficients Aki related to reception level) are transmitted to the radio base station 10, and the radio base station transmits the transmission channel coefficients for all antenna beams from all mobile stations. Road coefficient matrix [H]
The inverse matrix [H] ^{−1 of} is calculated. On the other hand, in the present embodiment, the load of the calculation processing of the inverse matrix in the radio base station 10 is reduced.

Since the directivity of the antenna beam formed by each antenna element of the radio base station 10 is different, the transmission showing the state of the transmission path between the antenna beam directed in a certain direction of the mobile station and the mobile station. The road becomes the largest. For example,
Since the antenna beam # 1 shown in FIG. 6 is directed to the mobile station 20 (1), the mobile station 20 (1) has an SN (quality) of the pilot signal P1 transmitted by the antenna beam # 1. Is the highest. Therefore, the mobile station 20
The transmission path coefficient h11 corresponding to the combination of (1) and antenna beam # 1 has the largest value, while the mobile station 20 (1)
And transmission channel coefficient h corresponding to the combination of other antenna beams
21, h31, ..., hN1 are relatively small values.

Therefore, the channel coefficient matrix [H] (equation (2
In (4)), the transmission channel coefficient hki having a large value is partially concentrated, and the error can be suppressed to be small even if the inverse matrix is calculated from the transmission channel coefficient matrix. Therefore, the number of transmission path coefficients (coefficients related to the reception level) notified from each mobile station to the wireless base station is set to a predetermined upper number (eg, 3
Limited to one). In this way, by limiting the number of transmission channel coefficients to be notified from each mobile station to the wireless base station, the load for calculating the inverse matrix of the transmission channel coefficient matrix at the wireless base station is reduced.

For example, each mobile station 20 (i) considers the SN (quality) of the pilot signal and ranks the top three in order of magnitude.
The radio base station 10 is notified of the one transmission path coefficient hki, hji, hmi (coefficients Aki, Aji, Ami related to the reception level). As a result, the number of elements in each row of the channel coefficient matrix [H] generated in the wireless base station 10 becomes three. When one mobile station corresponds to one beam having the maximum transmission capacity, by appropriately replacing the rows of the transmission path coefficient matrix, for example,

[0162]

[Equation 7] As described above, it is possible to create a transmission channel coefficient matrix [H] in which effective values are concentrated in the diagonal region. By creating such a transmission path coefficient matrix [H], the calculation of the inverse matrix of the transmission path coefficients in the radio base station 10 becomes simple, and the processing speed can be improved.

Further, a fourth embodiment of the present invention will be described.

In the present embodiment, each mobile station is provided with an adaptive antenna function to realize better reception characteristics in each mobile station.

The mobile communication system according to this embodiment is
For example, it is configured as shown in FIG.

In FIG. 16, as in the mobile communication system according to the second embodiment (see FIG. 6) described above, the radio base station 10 has N mobile stations 20 (1) to 20 (N). N antenna beams to transmit the available signals #
1 to #N are formed by the multi-beam combining circuit 14. Each of the mobile stations 20 (1) to 20 (N) has a configuration in which a beam generation circuit (beamformer: (BFN)) for performing an adaptive antenna operation is added to the time equalization / synthesis circuit (T-EQ). It has a circuit 27. In each of the mobile stations 20 (1) to 20 (N), a time etc. is received based on a signal received in a state where an appropriate radio wave radiation pattern is formed by the beam generation circuit in the communication control circuit 27. Time equalization processing is performed in the chemical synthesis circuit.

The processing in such a system is performed by, for example,
The procedure is as shown in FIG.

In FIG. 17, in the mobile station 20 (i),
The delay time set in the time equalization synthesis circuit (T-EQ) of the communication control circuit 27 is initialized (delay time = 0), and the adaptive beam pattern formed in the beam generation circuit (BFN) is changed. Initialization (omnidirectional) is performed (S2011). Then, the example described above (see Figure 15)
Similarly to the above, from the radio base station 10, each antenna beam # 1 to
When the mobile station 20 (i) receives the pilot signal (PILOT) transmitted in #N (S101, S202), the pilot signal Pk having the maximum received power is detected from the received pilot signals (PILOT). (S203).
Then, the SN (quality) of the pilot signal (PILOT) Pk
The beam forming circuit (BFN) adjusts the adaptive beam pattern so that the maximum value becomes, and the time equalization combining circuit (T-EQ) performs time equalization combining processing (S2).
041).

In this state, similarly to the above-described example (see FIG. 15), in the mobile station 20 (i), the time coefficient and weight obtained by the time equalization combining processing are stored in the time coefficient / weight memory 25b. The coefficient Aki (corresponding to the transmission channel coefficient hki) related to the reception level is calculated by comparing the combined signal obtained by the storage (S205) and the time equalization combining process with the known pilot signal (S206). Then, the mobile station 20
In (i), the coefficient Aki is transmitted to the wireless base station 10 (S207). After that, the mobile station 20 (i) maintains the adaptive array pattern adjusted as described above.

The radio base station 10, which receives the coefficient Aki transmitted from each mobile station as described above (S102), is the inverse matrix of the channel coefficient matrix [H] as in the above-mentioned example (see FIG. 15). Calculation of [H] -1 (S103), Signal D to be transmitted to each mobile station using signal S (S1 to SN) corresponding to actual data addressed to each mobile station and the above inverse matrix [H] -1 (D1
To DN) (S104) and its signal D (D1 to D)
(N) transmission with each antenna beam # 1 to #N (S10
Perform 5).

When the mobile station 20 (i) having the adaptive array pattern maintained as described above receives the signal wave corresponding to the signal transmitted from the radio base station 10 as described above (S208), the time coefficient / The time coefficient and the weight stored in the weight memory 25b are used to perform the time equalization and combining processing of the received waves to obtain a combined signal. And
SN of signal Si to be transmitted to the mobile station 20 (i)
The time coefficient and the weight are finely adjusted so that the (quality) is maximized (S209). As a result, the mobile station 20
The signal Ri (= D1h1i + D2h2i + ...) Received in (i)
+ DNhNi) becomes the signal Si to be transmitted to the mobile station 20 (i) (S210, S211).

In such a mobile communication system, the signal received by each mobile station 20 (i) does not include an interference component, and the desired signal SI has a higher SN (quality).

Next, a fifth embodiment of the present invention will be described.

In the radio communication system according to each of the above-mentioned embodiments, since the radio base station 10 generates the inverse matrix [H] ⁻¹ of the transmission line function matrix [H] as a conversion operator, its transmission line coefficient The matrix must be square. Therefore, the radio base station 10 has the same number of antenna beams # as the mobile stations 20 (1) to 20 (N) with which communication is performed.
1 to #N are formed. On the other hand, in the present embodiment, radio base station 10 has mobile stations 20 (1) -20
More than the number of (N), for example, M antennas (antenna beams) # 1 to #M to mobile stations 20 (1) to 20.
A signal is transmitted to (N).

The mobile communication system according to this embodiment is
For example, it is configured as shown in FIG.

In FIG. 18, the radio base station 10 has an arithmetic processing circuit 110a and a communication device 110b.
The arithmetic processing circuit 110a includes the mobile stations 20 (1) to 20 (20).
From the signals S1 to SN to be transmitted to (N), each antenna # 1 to
Signals D1 to DM to be transmitted are created from #M. Then, the communication device 110b uses the M antennas # 1 to #
Signal D from M to each mobile station 20 (1) to 20 (N)
Send 1 to DM.

Each mobile station 20 (i) (i = 1 to N) receives the pilot signals P1 to PM transmitted from each antenna # 1 to #M of the radio base station 10, and receives each antenna and the mobile station. , HMi are measured with respect to 20 (i), and the wireless base station 10 is notified of the transmission path coefficients h1i, h2i ,. The radio base station 10 is connected to each mobile station 20.
Transmission coefficient h1i, h2i, ..., hMi notified from (i)
Then, a transmission channel coefficient matrix [H] is created from the transmission channel coefficient matrix [H] and a signal Di to be transmitted to each mobile station 20 (i) is generated based on the transmission channel coefficient matrix [H].

The signal Di is generated, for example, as follows.

The relationship between the signals D1 to DM transmitted from the antennas # 1 to #M and the received signals R1 to RN at the mobile stations 20 (1) to 20 (N) is as follows. Using the transmission path coefficient hki between the mobile station 20 (i) and each mobile station 20 (i), as described in the conventional system (see Expression (1)),

[0180]

[Equation 8] It is expressed as. Expressing these relationships in the form of a determinant,

[0181]

[Equation 9] become that way. Here, each matrix is converted into its element array (column ×
If expressed in a simple notation of (line), the above formula (27)
Is described as [R (1 × N)] = [H (M × N)] [D (1 × M)] (28). Since the number M of antennas and the number N of mobile stations are different (M> N), the channel coefficient matrix [H] is not a square matrix.

The matrix [Z] is used as a conversion operator for converting the signals S1 to SN to be transmitted to the mobile stations 20 (1) to 20 (N) into the signals D1 to DM transmitted from the antennas # 1 to #M. ], It is expressed as follows.

[0183]

[Equation 10] When each matrix in this determinant is expressed by the simple notation as described above, the above formula (29) is [D (1 × M)] = [Z (N × M)] [S (1 × N) )] ... (30) is described.

As described above, the channel coefficient matrix [H] is M ×
When the matrix is N, the signal D1 to be transmitted to each mobile station is
~ DN and the signals S1 to SM to be transmitted to each mobile station are N
It can be associated with the matrix [Z] (conversion operator) that is a × M matrix.

Substituting the above equation (29) into the above equation (27),

[0186]

[Equation 11] When the above equation (30) is substituted into the equation (28), [R (1 × N)] = [(H (M × N)] [Z (N × M)] [S (1 × N)] is expressed as (31 ′).

Here, [H (M × N)] [Z (N ×
M)], an N × N matrix [T (N × N)] is generated. This matrix T is composed of the following elements.

[0188]

[Equation 12] In this equation (32), Σ represents the sum of each term in which m is 1 to N.

By using the N × N matrix T as described above, the signals S1 to SN to be transmitted to the mobile stations 20 (1) to 20 (N) and the signal R1 to be received by each mobile station are transmitted. The relationship with RN is represented by [R (1 × N)] = [T (N × N)] [S (1 × n)] (33).

From the above equation (33), each mobile station 20 (i)
The condition that the received signal Ri in (1) becomes only the signal Si component to be transmitted is that all components other than the diagonal components of the matrix T become zero. That is, the matrix T becomes as follows.

[0191]

[Equation 13] From the above equation (33) and the above equation (34), the above condition is: ΣZKm · hLm (m = 1 to M) = 0 (K ≠ L, K = 1 to N, L = 1 to N) (35) Becomes

Therefore, each transmission line coefficient hLM is measured, and the matrix [Z] having each ZKm satisfying the above equation (35) as an element
And the signals [D1 to DM] calculated according to the above equation (30) are calculated using the matrix [Z] for each antenna # 1 to #M.
From each mobile station 20 (1) -20
In (N), the signals S1 to
You will be able to receive SN.

If M = N, the matrix [Z] is uniquely determined. In this case, the matrix [Z] is an inverse matrix of the channel coefficient matrix [H], as described in each of the above embodiments.

However, since the number M of antennas is larger than the number N of mobile stations (M> N), the number of variables ZKm in the above equation (35) becomes larger than the number of equations (N), and each variable Z
Km does not uniquely decide. Therefore, the matrix (Z) is based on the condition that the expression (35) is satisfied (eradication of interference) and that the desired signal is maximized by using the remaining degrees of freedom.
To calculate. The conditions are as follows.

RJ = ΣZJm · hJm (m = 1 to M): Amplitude maximization for each J (J = 1 to N) (36) Here, RJ is received by the mobile station 20 (J). Signal strength, and maximizes this RJ (amplitude (power)) while satisfying the equation (35) for each J. The matrix [Z] is obtained by performing such an operation. However, since the total transmission power of each signal is actually determined, equation (36) is used within that range.
Will be the maximum. Specifically, since there is electric power, the equation (36) may be squared and maximized. Expression (36) to which this condition is applied is a function of (MN) variables. That is, when the difference between the number M of antennas and the number N of mobile stations is 1, the formula (3
6) is one variable, and if the difference is 2, then equation (36)
Becomes two variables. When the equation (36) is squared and maximized, it becomes a quadratic function, and there is a maximum value. That is, RJ given by equation (36) is a condition (equation (3
By satisfying 5)) and further maximizing by using the remaining variables, the signal strength is maximized.

Using the matrix [Z] obtained by performing such an operation, calculation with the desired signal matrix [S] as shown in equations (29) and (30) is performed, and The signals D1 to DM to be transmitted from the antennas # 1 to #M are generated.

Regarding the processing for calculating the matrix [Z] described above, for example, as shown in FIG.
~ D3 (M = 3) and two (N
= 2) base stations 20 (1) and 20 (2) will be specifically described as an example of a mobile communication system.

In such a mobile communication system, qualitatively, the interference of the mobile station 20 (1) disappears by forming an antenna pattern in which three antennas direct the null toward the mobile station 20 (2). . Therefore, although one null is sufficient, if there are three antennas, an antenna pattern having two nulls can be formed. Therefore, the power input to the mobile station 20 (1) is maximized by using the degree of freedom for creating another null.

Each antenna # 1 to # 3 and each mobile station 20
(1), 20 (2) corresponding to the transmission line coefficients (h11, h
21, h31, h12, h22, h32) are already known. Signals R1 and R2 received by each mobile station 20 (1), 20 (2) are obtained by using signals D1 to D3 transmitted from each antenna # 1 to # 3.

[0200]

[Equation 14] Is expressed as follows (see Expression (27)). Since the transfer coefficient matrix (H) is not a square matrix, its inverse cannot be obtained directly. Arithmetic processing circuit 11 of radio base station 10
0a, the signal D transmitted from each antenna # 1 to # 3
The association between 1 to D3 and the signals S1 and S2 to be transmitted to the mobile stations 20 (1) and 20 (2) is made as follows using the matrix [Z] (see formula (29)). ).

[0201]

[Equation 15] Therefore, the relationship between the signals R1 and R2 received by the mobile stations 20 (1) and 20 (2) and the signals S1 and S2 to be transmitted to the mobile stations 20 (1) and 20 (2) is as follows. (See equation (31)).

[0202]

[Equation 16] By calculating the above formula (39), the signals R1 and R2 and the signal S1,
The matrix T that associates with S2 is calculated as follows (see equation (32)).

[0203]

[Equation 17] Here, the mobile stations 20 are not interfered with by the signals S1 and S2.
In order to be received by (1) and 20 (2), it is necessary that the components other than the diagonal components of the matrix T be zero (see the equation (34)) as follows.

[0204]

[Equation 18] That is, the condition represented by the following formula is required. Condition that the mobile station 20 (1) does not interfere with the mobile station 20 (2) h12Z11 + h22Z12 + h32Z13 = 0 (42) Condition that the mobile station 20 (2) does not interfere with the mobile station 20 (1) h11Z21 + h21Z22 + h31Z13 = 0 ... (42) 43) In each of the above equations (42) and (43), h is a coefficient (transmission path coefficient) already given, and Z is equation (41).
If it satisfies, it can be decided arbitrarily.

Since the matrix [Z] is symmetric, the mobile stations 20 (1) and 20 (2) have the same conditions.
Consider only mobile station 20 (1).

When the above equation (42) is transformed,     Z13 =-(h12Z11 + h22Z12) / h32 (44) Is obtained.

On the other hand, the received power of the mobile station 20 (1) (R
Equation (41) is calculated as follows in 1) as follows.

[0208]     R1 = (h11Z11 + h21Z12 + h31Z13) S1 (45) By substituting the equation (44) into the equation (45),   R1 = (h11Z11 + h21Z12 + h31 (-(h12Z11 + h22Z12) / h32)) S1   = 1 / h32 ((h11h32-h12h31) Z11 + (h21h32-h22h31) Z12) S1     = A ・ Z11 + B ・ Z12 (46) In the above formula (46), A = S1 / h32 (h11h32-h12h31) B = S1 / h32 (h21h32-h22h31) Is.

When the formula (46) is squared to find the maximum value of the electric power represented by the formula (46), R1 ² = A ² · Z11 ² + B ² · Z12 ² + A · BZ11 · Z12 (47) ).

On the other hand, from the equation (38), the mobile station 20 (1)
Is transmitted to each antenna # 1 to # 3, Becomes If all the signals S1, S2, S3 have the same power and are all 1, the transmission power P1 of the signal S1 transmitted from the radio base station 10 is P1 = Z11 ² + Z12 ² + Z13 ² (49) Become. For example, since there is no problem even if the total power is standardized to 1, the above formula (49) can be expressed as Z11 ² + Z12 ² + Z13 ² = 1 (50).

Substituting equation (44) into equation (50),     Z11²+ Z12²+ (-(H12Z11 + h22Z11) / h32)²= 1 (51) Becomes And when this equation (51) is arranged,   (H32²+ H12²) Z11²+ (H22²+ H32²) Z12²+ H12h22 / Z11Z12 + h32 ² = 0 (52) Becomes

Solving equation (52) for Z12,
Substituting it into equation (43), the variable in equation (47) is changed to Z11.
Only Then, the maximum value of R1 represented by the equation (47) is obtained, and Z11 at that time is clarified. Substituting Z11 into equation (52) reveals Z12, and further substitutes Z11 and Z12 into equation (44) to obtain Z13.

In this way, the values of Z11, Z12 and Z13 are clarified, and the mobile station 20
By performing the calculation for (2), Z21, Z22, Z23
The value of becomes clear.

As a result, all the elements of the matrix (Z) are clarified, and the signals S1 and S2 to be transmitted to the mobile stations 20 (1) and 20 (2) are transmitted from the antennas # 1 to # 3. The power signals D1, D2, D3 are calculated according to equation (38).

In the present embodiment, the transmission path coefficient h is treated as a symbol, so that the expression is relatively complicated. However, the transmission path coefficient h is actually expressed as described in the above-mentioned embodiments. Are all given as complex numbers, each expression represents a simple numerical calculation. Also, the solution is generally uniquely determined.

In this embodiment, the number M of antennas is one more than the number N of mobile stations, and therefore the equation (47) to be maximized is one.
It became a variable, but the number M of antennas was 1 more than the number N of mobile stations.
If there are more than the above, the equation (47) to be maximized becomes a multivariable, and the calculation of the maximum value becomes complicated.

In this embodiment, the signal power (S
Although 1) was standardized (limited) to 1 (see equation (50)),
This standardization (limitation) differs for each system, and various methods are conceivable, such as standardizing (limiting) the total power of each signal or limiting the total power ratio of each signal.
The limiting method can be appropriately determined from the conditions in the system.

According to the system of the fifth embodiment as described above, even if the number M of antennas of the radio base station 10 and the number N of mobile stations are different (M> N), each mobile station It becomes possible to receive signals without interference.

Further, a sixth embodiment of the present invention will be described.

The present embodiment proposes a method of obtaining a transmission line coefficient in a CDMA mobile communication system.

The mobile communication system according to this embodiment is
Similar to the fifth embodiment described above, for example, it is configured as shown in FIG. In this mobile communication system, packet transmission is basically performed, and circuit switching type transmission is also possible by continuously performing the packet transmission.
Also, the frame format of the signal transmitted from the radio base station 10 to each mobile station 20 (i) is as shown in FIG. 14, as in the above-described embodiment.

Each mobile station 20 (i) is constructed, for example, as shown in FIG. 20, and the radio base station 10 is constructed, for example, as shown in FIG.

In FIG. 20, this mobile station 20 (i)
Is a duplexer 211, LNA (Low Noise Amplifier: Low)
Noise Amp.)-Down converter 212, pilot despreading processing unit 213, data despreading processing unit 214, PA
(Power amplifier: Power Amp.)-Up converter 12
5, a spread processing unit 126, and a transmission line coefficient calculation unit 217.

Mobile station 20 transmits M kinds of pilot signals (spread with spreading codes C1 to CM as described later) transmitted from antennas # 1 to #M of radio base station 10.
When (i) is received, each pilot signal is transmitted to the pilot despreading processing unit 21 via the LNA / down converter 212.
3 is supplied. The pilot despreading processor 213 despreads each pilot signal using spreading codes C1 to CM,
Regenerate the original pilot signal. The reproduced pilot signal is further supplied to the transmission path coefficient calculation unit 217.

As in the case of each of the above-described embodiments, the transmission line coefficient calculation unit 217 compares the regenerated pilot signal with a known pilot signal, and determines each of the antennas # 1 to #M. Transmission line coefficients h1i to hMi representing the state of the transmission line with the mobile station 20 (i) are calculated. The transmission line coefficients h1i to h obtained by the transmission line coefficient calculation unit 217
Mi is supplied to the spread processing unit 126, and spread processing is performed using the spread code Czi. Then, the spread signal including the transmission path coefficients h1i to hMi obtained by the spreading process is transmitted via the PA / up converter 215 and the duplexer 211.

The pilot despreading processing unit 213 and the data despreading processing unit 214 can operate independently. The actual data signal R received by the mobile station 20 (i)
1 (packet) is supplied to the data despreading processing unit 214 via the duplexer 211 and the LNA / down converter 212. This data despreading processing unit 214 reproduces the original actual data signal from the received signal R1 using the spreading code C0. The reproduced actual data is the mobile station 20.
In (i), predetermined processing (voice output, data output, etc.) is performed.

On the other hand, in FIG. 21, the radio base station 10
Is the duplexer 1 for each antenna #k (k = 1 to M).
11 (k), LNA / down converter 112 (k), PA
-Up converter 113 (k), despreading processing unit 114
(K), pilot spreading processor 115 (k), data spreading processor 116 (k), and transmission path coefficient receiver 117.
Have (k). The radio base station 10 includes an information generation unit 118 that generates signals S1 to SN to be transmitted to the mobile stations 20 (1) to 20 (N), and a conversion that generates a matrix [Z] as the conversion operator described above. It has an operator calculator 119 and a transmission signal calculator 120 that generates signals D1 to DM to be transmitted from the antennas # 1 to #M.

Pilot spreading processing section 115 (k) spreads pilot signal Pk associated with antenna #k using spreading code Ck. Then, the spread signal of the pilot signal Pk is transmitted from the antenna #k via the PA / up converter 113 (k) and the duplexer 111 (k). The data spreading processing unit 116 (k) can operate independently of the pilot spreading processing unit 115 (k), and spreads the signal Dk generated by the transmission signal calculation unit 120 using the spreading code C0. To do. Then, the spread signal of the signal Dk is transmitted from the antenna #k via the PA / up converter 113 (k) and the duplexer 111 (k).

When the spread signal including the transmission path coefficient from each mobile station 20 (i) is received by the antenna #k,
The received signal RTk passes through the duplexer 111 (k) and the LNA / down converter 112 (k) to the despreading processing unit 114.
Is supplied to (k). This despreading processing unit 114 (k)
Despreads the received signal RTk using the spreading code Czk. Then, the signal obtained by the despreading is supplied to the transmission path coefficient receiving unit 117 (k). The transmission path coefficient receiving unit 117 (k) obtains the transmission path coefficients h1i, h2i, ..., HMi from the supplied signal. The transmission line coefficients h1i, h2i, ..., HMi thus obtained are calculated by the conversion operator calculation unit 1
19 are supplied.

The conversion operator calculation unit 119 calculates the matrix [Z] according to the procedure described above (Equation (35),
Expression (36), Expression (40) to Expression (52)). The matrix [Z] obtained by the conversion operator calculation unit 119 and the signal Si to be transmitted to each mobile station 20 (i) generated by the information generation unit 118 are supplied to the transmission signal calculation unit 120. The transmission signal calculation unit 120 calculates the signal Dk to be transmitted from each antenna #k according to the above equation (29). The signal Dk obtained in this way is the data diffusion processing unit 11 described above.
6 (k). Then, the data spreading processing unit 116 (k) spreads the signal Dk with the spreading code C0 at the downlink frequency, and the data signal obtained by the spreading processing is the PA / up converter 113 (k). And from the antenna #k via the duplexer 111 (k).

The radio base station 10 having the above-mentioned configuration is
For example, the signal of the frame format shown in FIG. 14 is transmitted to each mobile station 20 (i) (i = 1 to N).
In this case, for example, after the channel coefficient hki between each antenna #k (k = 1 to M) of the radio base station 10 and each mobile station 20 (i) is estimated by the pilot signal of the packet A, , The signal Dk generated by using the transmission line coefficient hki
Is included in the packet B as actual data and the wireless base station 1
It is transmitted from antenna #k of 0.

[0232] The radio base station 10 and each mobile station 20 (i)
The specific communication with and is performed according to the procedure shown in FIG. 22, for example.

In FIG. 22, after the synchronization is established between the radio base station 10 and each mobile station 20 (i), the radio base station 10 transmits the pilot signals P1 to PM of the packet A to the spread codes C1 to CM. In step S111, the spread processing is performed, and the spread signals obtained by the spread processing are transmitted from the corresponding antennas # 1 to #M (S111). Then, each mobile station 20 (i) receives the spread signal including the pilot signals P1 to PM (S221). Received signal Ri at each mobile station 20 (i)
Ri = h1iP1C1 + h2iP1C2 + ... + hMiPMCM (53) When the received signal Ri is despread using the spreading codes C1 to CM, Ri (C1) = h1i.P1 Ri (C2) = h2i.P1 ... Ri (CM) = hMi.PM ... (54) (S222). Since the pilot signals P1 to PM are known, the signals Ri after despreading with the respective spreading codes C1 to CM are
When (Ck) is multiplied by the known spread code Ck, the transmission line coefficients h1i to hMi between the antennas # 1 to #M and the mobile station 20 (i) are obtained as follows (S22).
3).

H1i = R (C1) / P1 h2i = R (C2) / P2 ...... hMi = R (CM) / PM (55) In this way, the mobile station 20 (i) controls the wireless base station 10 When the transmission path coefficients h1i to hMi between each of the antennas # 1 to #M are obtained, the transmission path coefficients h1i to hMi are spread by the appropriate spreading code Czi at the upstream frequency (S224). ). Then, the spread signal including the transmission path coefficients h1i to hMi obtained by the spreading process is transmitted to the mobile station 20.
It is transmitted from (i) to the wireless base station 10 (S225).

After transmitting the pilot signal of packet A (S111), the radio base station 10 communicates with all mobile stations 20 (1) to 20 (20) in the data transmission section of pilot A. Each spread signal including the transmission path coefficients h11 to hM1, h12 to hM2, ..., H1N to hMN from (N) is received by each antenna #k (S11).
2). Then, the received signal RTk at each antenna #k is despread with the spreading code Czk (S113), and the transmission path coefficients h11 to hM1, h12 to hM2, ... H1N to hMN are obtained.

In this way, in the radio base station 10, the transmission path coefficients h11 to hM1, h12 to hM2, ... H1N between the antennas # 1 to #M and the mobile stations 20 (1) to 20 (N), respectively. ~ When hMN is obtained, the procedure (Expression (35), Expression (36), Expression (40) to Expression (52) using the transmission path coefficient as described above is used.
The matrix (Z) is calculated according to the reference (S114).
Then, the radio base station 10 and the matrix [Z] and the signals S1 to SN to be transmitted to the mobile stations 20 (1) to 20 (N).
And each antenna # 1 to # according to the above equation (29).
The signals D1 to DM to be transmitted from M are calculated (S11).
5).

The signals D1 to DM calculated in this way
Is spread by the spreading code C0 (S116). The spread signal obtained by the spreading process is transmitted from the corresponding antenna in the data section of packet B (S117).

The signals transmitted from the antennas # 1 to #M of the radio base station 10 are transmitted to the mobile station 20 (i) as described above.
Is received (S226), the received signal Ri is despread with the spreading code C0 (S227). As a result, the mobile station 20 (i) obtains the signal Si to be transmitted to the mobile station 20 (i) (see the equation (41)) (S228).

The radio base station 10 successively receives signals from other mobile stations, as in the above-described example (see FIG. 15), and
A new communication start / end request is received, and the latest transmission path coefficient matrix is always generated (S118 to S120).

In this example, all the signals to be transmitted from all the antennas # 1 to #M are spread and transmitted with the same spreading code C0, and the signals received by each mobile station 20 (i) are spread with the same spreading code. Each mobile station 20 is simply despread with the code C0.
In (i), the desired signal Si can be obtained without being affected by interference.

In the communication procedure (see FIG. 22) in the radio communication system according to the present embodiment, the transmission channel coefficient matrix [H] is estimated and calculated by the pilot signal of the previous packet (for example, packet A), and The actual data is transmitted in packets (for example, packet B). Since the estimation calculation of this transmission channel coefficient matrix [H] and the transmission of actual data can be performed completely independently, a new transmission channel coefficient matrix is calculated from the pilot signal at the time of data transmission, as shown in FIG. By using the transmission path coefficient matrix for the next data transmission, a lot of information can be sent without waste.

Next, a seventh embodiment will be described.

In the mobile communication system according to this embodiment, the antenna pattern is formed by using the multi-beam antenna as in the first embodiment (see FIG. 1).

The mobile communication system according to this embodiment is
For example, it is configured as shown in FIG.

In FIG. 23, the radio base station 10 has a multi-beam combining circuit (MBF) 14, and the multi-beam combining circuit 14 forms a plurality of antenna beams from the beam antenna 13. The radio base station 10 uses the plurality of antenna beams to move the mobile stations 20 (1) to 20 (20) to
Communicate with (N).

Since the antenna beams formed as described above have different directivities, the transmission path coefficient between the antenna beam directed in a certain direction of the mobile station and the mobile station has the largest value. For example, antenna beam # 1 shown in FIG.
Is directed to the mobile station 20 (1), the SN (quality) of the pilot symbol P1 is the highest. Therefore,
The transmission path coefficient h11 between the antenna beam # 1 and the mobile station 20 (1) has the largest value. Since the other antenna beams do not face the direction of the mobile station 20 (1), the transmission path coefficients h21, h31, ..., HM1 between the other antenna beams and the mobile station 20 (1) are relatively small. It becomes a value. Therefore, in the channel coefficient matrix [H], elements having relatively large values are concentrated in a part, and the error is small even if the matrix [Z] obtained from the channel coefficient matrix [H] is calculated. Can be suppressed.

Further, as shown in FIG. 23, basically, each mobile station 20 (1) -2
It is preferable that there is one transmission path to 0 (N). However, in reality, it is common in the environment of a mobile communication system that a plurality of transmission paths exist from one antenna (antenna beam) to one mobile station. 1 like this
Even if there are multiple transmission paths from one antenna to one mobile station, the characteristics of those transmission paths can be linearly shared, so that the transmission characteristics corresponding to those characteristics, that is, multiple transmission paths The channel coefficients can be put together into one transmission channel coefficient h. Alternatively, the delayed waves corresponding to the respective transmission lines can be individually received and optimally combined to obtain one transmission line coefficient h.

However, even if the transmission path environment (transmission path) is changed slightly (for example, about 1/4 wavelength), the distance between the individual transmission paths is changed, the phase difference between them is changed, and the transmission path coefficient h is changed. It fluctuates greatly. So-called fading occurs. Therefore, if there is only one transmission path from the antenna or antenna beam to each mobile station, such fluctuations will be very gentle. To do this,
It is necessary to restrict each antenna pattern to suppress the generation of various reflected waves. Therefore, narrowing down each antenna beam generated in the radio base station 10 as in the mobile communication system according to this embodiment is effective in reducing interference at each mobile station.

Furthermore, when forming a plurality of antenna beams in the radio base station 10 as described above, each mobile station 20
Since the transmission path coefficient h related to the antenna beam heading to (i) is the largest and the transmission path coefficient related to the other antenna beams is relatively small, each mobile station 20 (i) has the SN (quality) of the pilot signal. ), It is possible to notify the radio base station 10 of the top three transmission path coefficients in order of size. In the case of the system shown in FIG. 23, for example, the mobile station 20 (1) uses the antenna beam #
The radio base station 10 is notified of the transmission path coefficients h11, h41, and h71 related to 1, # 4, and # 7. The mobile station 20 (2) receives the transmission path coefficients h22, h5 related to the antenna beams # 2, # 5, # 1.
2. Notify the h12 radio base station 10. Furthermore, the mobile station 20
(N) notifies the radio base station 10 of the transmission path coefficients hMN, h9N, and h8 related to the antenna beams #M, # 9, and # 8. Therefore, the amount of information notified from each mobile station 20 (i) to the radio base station 10 can be reduced.

Further, in this case, the radio base station 1 which has received the notification of each of the three transmission path coefficients from each mobile station 20 (i).
There are three elements in each row of the channel coefficient matrix [H] generated at 0. When one mobile station corresponds to one beam having the maximum transmission capacity, by appropriately replacing the rows of the transmission path coefficient matrix, for example,

[0251]

[Formula 19] As described above, it is possible to create a transmission line coefficient matrix [H] in which effective values are concentrated on a diagonal line. By creating such a channel coefficient matrix [H], the matrix [Z] in the radio base station 10 can be easily calculated, and the processing speed can be improved.

When the number of transmission path coefficients notified from each mobile station 20 (i) is limited to three as described above, the radio base station 10 and each mobile station 20 (i) are shown in FIG. 24, for example. Follow the procedure.

In FIG. 24, similarly to the above-mentioned example (FIG. 22), the radio base station 10 transmits spread signals including pilot signals corresponding to the respective antenna beams (S111). When the mobile station 20 (i) receives the spread signal from the radio base station 10, the mobile station 20 (i) despreads the spread signal using the spread codes C1 to CM (S222), and outputs the pilot signals P1 to PM corresponding to the respective antenna beams. obtain. Then, the mobile station 20 (i) receives the acquired pilot signals P1 ...
The upper three pilot signals Pi, Pj, and Pk with high SN (quality) are extracted from PM (S2230). Thereafter, the transmission path coefficients hii, hji, hki are calculated from the extracted pilot signals Pi, Pj, Pk using the above equation (55) (S2231).

The three transmission line coefficients hii, hji, hki
Is spread by the spreading code Czi and transmitted by the radio base station 10 (S2241, S2251).

When the radio base station 10 receives the spread signal including the three transmission path coefficients hij, hji, hki from each mobile station 20 (i) (S112), it despreads the received signal RTk with the spread code Czk. , Each transmission path coefficient is acquired (S11
3). Then, from the acquired transmission line coefficients, the transmission line coefficient matrix [H] (Equation (5
6)) is created (S1140).

Thereafter, similarly to the above-described example (FIG. 22), the radio base station 10 uses the channel coefficient matrix [H] to the matrix [Z].
(S114), generation of transmission signals D1 to DM from signals S1 to SN and matrix [Z] (S115), spread processing of transmission signals (S116), transmission of spread signals with each antenna beam (S117). To do. Also, each mobile station 20 (i)
Similar to the above-described example (FIG. 22), signal reception from the radio base station 10 (S226) and despreading of the received signal Ri with the spreading code C0 (S227) are performed, and the mobile station 20 (i) concerned.
Then, the signal S i to be transmitted is acquired (S228).

Further, the eighth embodiment will be described.

In the present embodiment, each mobile station is provided with an adaptive antenna function to realize better reception characteristics in each mobile station.

The mobile communication system according to this embodiment is
For example, it is configured as shown in FIG.

In FIG. 25, the radio base station 10 transmits signals to N mobile stations 20 (1) to 20 (N) as in the case of the seventh embodiment (see FIG. 23) described above. The multi-beam combining circuit 14 forms M antenna beams # 1 to #M. Each mobile station 20 (1)-
20 (N) has a beam forming / rake combining circuit 28 for realizing an adaptive antenna function.

The operations of the radio base station 10 and the mobile stations 20 (1) to 20 (N) in such a system are basically the same as those in the system described above (see FIG. 22), -Each mobile station 20 having the Rake combining circuit 28
The operation of (i) is different from the system described above. Each mobile station 2
In 0 (i), the beam forming / rake combining circuit 28 performs an adaptive operation and a rake combining operation before obtaining the transmission path coefficient, and makes the radiation pattern of the antenna beam and the rake combining coefficient appropriate.

The operation of the radio base station 10 and each mobile station 20 (i) is specifically carried out, for example, according to the procedure shown in FIG.

In FIG. 26, the mobile station 20 (i) operates the beam forming / rake combining circuit 28 to make the antenna pattern omnidirectional before receiving the pilot signal from the radio base station 10 (initial stage). Along with this, the RAKE combining coefficient is initialized (S220). In this state, when the mobile station 20 (i) receives the spread signal including the pilot signal (S111) transmitted from each antenna beam from the radio base station 10 (S221), the mobile station 20 (i) receives the spread signal as in the system described above. The signal is despread using the spreading codes C1 to CM to obtain a pilot signal (S222).
After that, the mobile station 20 (i) extracts the pilot signal Pk having the maximum SN (quality) from the acquired pilot signals P1 to PM (S2221). Then, the mobile station 20
In (i), the beam forming / rake combining circuit 28 adjusts the antenna pattern so that the SN (quality) of the pilot signal Pk is even higher and is the highest.
The Rake combining coefficient is optimized (S2222). An estimation calculation of the transmission line coefficients h1i, h2i, ..., HMi is performed using the antenna pattern and the Rake combining coefficient obtained as described above (S223).

The mobile station 20 (i) thereafter spreads the transmission path coefficients h1i, h2i, ..., HMi using the spreading code Czi (S224), as in the aforementioned system (S224), and transmits the spread data. A spread signal including the path coefficients h1i, h2i, ..., HMi is transmitted (S225). In addition, the mobile station 20
In (i), the shape of the antenna pattern at that time is maintained and the rake combining coefficient is held.

When the spread signal including the transmission path coefficients h1i, h2i, ..., HMi transmitted from each mobile station 20 (i) as described above is received (S112), the radio base station 10
Similar to the system described above, despreading of the received signal is performed (S113), the transmission channel coefficient is acquired, and the matrix (A) is calculated using the transmission channel coefficient (S114). After that, the radio base station 10 calculates the signals D1 to DM to be transmitted from each antenna pattern (S115), spreads the signals D1 to DM using the spreading code C0 (S116), and transmits them with each antenna beam. Yes (S117).

When the mobile station 20 (i) receives the data signal from the radio base station 10 after transmitting the transmission path coefficient as described above (S226), the received signal Ri is despread with the spreading code C0. By doing so (S227), the signal Si to be transmitted to the mobile station 20 (i) is acquired (S2).
28).

According to the above-mentioned processing, each mobile station 2
At 0 (i), the quality of the pilot signal corresponding to a certain transmission path becomes better, and the quality difference from the pilot signal corresponding to another transmission path becomes larger. As a result, the individual differences in the transmission path coefficient h increase. Therefore, for example, when extracting a limited number of transmission channel coefficients as in the above-described system (see FIG. 24), it becomes easy to select a transmission channel coefficient relating to a pilot signal of higher quality. Further, the quality of the received signal at each mobile station 20 (i) can be improved.

Further, in each mobile station 20 (i), the adaptive operation of the antenna and the determination of the rake combining coefficient are performed at the time of receiving the pilot signal. Therefore, the processing should be performed in parallel with the normal data receiving operation. You can Therefore, it is not necessary to consider the delay for the processing.

In this embodiment, both the adaptive antenna and the rake combining are used together, but it is not always necessary to use them together. Either one may be used. Further, the adaptive operation and the Rake combining method are not particularly limited, and are realized by using spatial and temporal equalization, a filter, and a combining function. In the above-described embodiment, the Rake combining circuit is used as the equalizer in the time direction, but other time equalizers, such as a transversal filter, may be used.

Generally, in a mobile communication system, many channels are used to prevent interference between mobile stations.
The method according to the present invention (first to eighth embodiments) spatially separates the signals in the same channel to eliminate interference. However, it seems difficult to completely eliminate interference as far as space is concerned. Therefore, it is considered that the method according to the present invention can obtain a greater effect by being used in combination with a technique such as channel arrangement.

Therefore, in the method according to the present invention, when there is a difference between the number of antennas and the number of mobile stations (see the fifth to eighth embodiments), there is no difference (from the first embodiment to the first embodiment). However, the number of antennas and the number of mobile stations should be optimized in consideration of the channel allocation technology depending on the situation. It seems that the appropriate operation method is to set it in a proper manner.

In the fifth to eighth embodiments, each antenna # 1 to #M and each mobile station 20 is used.
The transmission line coefficient h between (1) to 20 (N) has been described as a value that has already been given, but this transmission line coefficient h can be changed from the first embodiment to the fourth embodiment. It can be measured by a solid method.

The transmission line coefficient h is not limited to that defined by the equation (9) described in the first embodiment. It may be defined by another method as long as it represents the state of the transmission path between each antenna and the mobile station.

In each of the above examples, the radio base station 10 corresponds to the first communication device, and the mobile stations 20 (1) to 20 (N)
Corresponds to the second communication device. The process in S101 shown in FIGS. 15 and 17, and the S shown in FIGS. 22, 24 and 26.
The processing in 111 corresponds to the pilot signal transmission procedure, respectively. The processing in S201 to S207 shown in FIGS. 15 and 17, the processing in S102, and part of the processing in S103, the processing in S2011 to S207, and the processing in S102 22 and part of the processing in S103, S221 to S221 in FIG.
The processing in S225, S221 to S2251 shown in FIG.
26 and the processing of S220 to S225 shown in FIG. 26 are the same as the transmission path coefficient information generation procedure.

Also, part of the processing in S103 shown in FIGS. 15 and 17, the processing in S113 and S114 shown in FIG. 22, the processing in S113, S1140 and S114 shown in FIG. 24, and the S113 shown in FIG. The processing in S114 corresponds to the conversion operator calculating means, the processing in S104 shown in FIGS. 15 and 17 and the processing in S115 shown in FIGS. 22, 24 and 26 correspond to the signal conversion procedure,
The processing in S105 shown in FIGS. 15 and 17 and the processing in S116 and S117 shown in FIGS. 22, 24 and 26 correspond to the signal transmission procedure, respectively.

[0276]

As described above, claims 1 to 53 are provided.
According to the present invention described, when the signal is transmitted from the plurality of antennas of the first communication device to the plurality of second communication devices, the received signal at each second communication device is It is possible to provide a wireless communication method and system in which the signal becomes the same as that to be transmitted to the second communication device, and the interference in each second communication device can be relatively easily reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a mobile communication system according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a first model for considering a transfer function (transmission path coefficient).

FIG. 3 is a diagram showing a second model for considering a transfer function (transmission path coefficient).

FIG. 4 is a diagram showing a third model for considering a transfer function (transmission path coefficient).

FIG. 5 is a diagram showing an example of states of a signal transmitted from a wireless base station and a signal arriving at a mobile station in the third model.

FIG. 6 is a diagram showing a configuration example of a mobile communication system according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a fourth model for considering a transfer function (transmission path coefficient).

FIG. 8 is a diagram showing a fifth method for considering a transfer function (transmission path coefficient).

FIG. 9 is a block diagram showing a specific configuration example of a radio base station in the mobile communication system according to the second embodiment.

FIG. 10 is a block diagram showing a specific configuration example of each mobile station in the mobile communication system according to the second embodiment.

11 is a block diagram showing a configuration example of a time / weight adjustment unit in the mobile station shown in FIG.

12 is a block diagram showing another configuration example of the time / weight adjustment unit in the mobile station shown in FIG.

FIG. 13 is a diagram for explaining an operation example of time equalization.

FIG. 14 is a diagram showing an example of a signal format.

FIG. 15 is a flowchart showing an example of a processing procedure in a radio base station and each mobile station.

FIG. 16 is a diagram showing a configuration example of a mobile communication system according to a fourth embodiment of the present invention.

FIG. 17 is a flowchart showing an example of a processing procedure in a radio base station and each mobile station.

FIG. 18 is a diagram showing a configuration example of a mobile communication system according to a fifth embodiment of the present invention.

FIG. 19 is a diagram illustrating a specific configuration example of a mobile communication system.

FIG. 20 is a block diagram showing a configuration example of each mobile station according to a sixth embodiment of the present invention.

FIG. 21 is a block diagram showing a configuration example of a radio base station according to a sixth embodiment of the present invention.

FIG. 22 is a flowchart showing an example of a processing procedure in a radio base station and each mobile station.

FIG. 23 is a diagram showing a configuration example of a mobile communication system according to a seventh embodiment of the present invention.

FIG. 24 is a flowchart showing an example of a processing procedure in a radio base station and each mobile station.

FIG. 25 is a diagram showing a configuration example of a mobile communication system according to an eighth embodiment of the invention.

FIG. 26 is a flowchart showing an example of a processing procedure in a wireless base station and each mobile station.

FIG. 27 is a diagram illustrating a configuration example of a conventional mobile communication system.

[Explanation of symbols]

10 radio base station 13 antenna unit 14 multi-beam combining circuit 15 reference antennas 20 (1) to 20 (N) mobile station 25 time equalizer / combiner 25a time / weight adjusting unit 25b time coefficient / weight memory 27 communication control circuit 101 ( 1) to 101 (M) up / down converter / shared device 102 (1) to 102 (M) demodulation unit 103 (1) to 103 (M) modulation unit 104 (1) to 104 (M) transmission path coefficient reception unit 105 (1) to 105 (M) Beam identification signal transmitter 106 (1) to 106 (M) Data transmitter 107 Information generator 108 Inverse matrix calculator 109 Transmit signal calculator 110a Arithmetic processing circuit 110b Communication device 111 (1) ) -111 (M) Duplexer 112 (1) -112 (M) LNA / down converter 113 (1) -113 (M) PA / up-converter 114 (1) to 114 (M) Despreading processing units 115 (1) to 115 (M) Pilot spreading processing units 116 (1) to 116 (M) Data spreading processing units 117 (1) to 117 (M) Transmission Channel coefficient receiver 118 Information generator 119 (Z) calculator 120 Transmission signal calculator 201 Up / down converter / shared device 202 Modulator 203 Modulator 204 Transmission channel coefficient transmitter 205 Calculation processor 211 Shared device 212 LNA / down Converter 213 Pilot despreading processor 214 Data despreading processor 215 PA / up converter 216 Spreading processor 217 Transmission path coefficient calculator

Claims (53)

[Claims] 1. A wireless communication method for performing wireless communication between a first communication device having a plurality of antennas and a plurality of second communication devices, comprising: changing from a first communication device to a plurality of antenna beams. Pilot signal transmission procedure for transmitting a pilot signal corresponding to each antenna beam to the plurality of second communication devices, and a pilot signal transmitted by each antenna beam from the first communication device and each second communication The state of the transmission line between the first communication device and the second communication device formed by each antenna beam based on the information indicating the relationship with the signal corresponding to the pilot signal received by the device The transmission channel coefficient information generation procedure for generating the transmission channel coefficient information is represented, and the transmission signal to be transmitted by each antenna beam obtained by converting the signal to be transmitted to each second communication device by the conversion operator is applied. A conversion operator calculation procedure for calculating the conversion operator based on the transmission path coefficient information such that the reception signal at each second communication device becomes a signal to be transmitted when transmitted by each antenna beam. , A signal conversion procedure for converting a signal to be transmitted to each second communication device into a transmission signal to be transmitted by each antenna beam using the conversion operator, and a transmission signal obtained by the conversion A wireless communication method including a signal transmission procedure of transmitting from an antenna beam from a communication device. 2. The wireless communication method according to claim 1, wherein the number of antenna beams formed by the first communication device is:
The number is the same as the number N of the second communication devices, and the transmission path coefficient information generation procedure is the pilot signal Pk transmitted by each antenna beam #k (k = 1 to N) from the first communication device, The transmission signals D1 to DN from the antenna beams # 1 to #N are based on the information indicating the relationship with the reception signal at each second communication device i (i = 1 to N) corresponding to the pilot signal Pk. And the received signals R1 to RN at the respective second communication devices 1 to N, [R] = [H] · [D] [R]: 1 × N matrix [D] consisting of elements R1 to RN: 1 × N matrix [H] consisting of elements D1 to DN: N × N matrix (k, i = 1 to N) consisting of elements hki is generated as channel coefficient information. , The conversion operator calculation procedure is the same as the above-mentioned channel coefficient matrix [H]
The conversion operator represented by the inverse matrix [H] ⁻¹ of the above is calculated, and in the above signal conversion procedure, the signals [S] = S1 to SN to be transmitted to each of the second communication devices 1 to N are ] = [H] ⁻¹ · [S], the signals to be transmitted by each antenna beam # 1 to #N are converted into [D] = D1 to DN, and the above signal transmission procedure is obtained by the above conversion. Signal D1 ~
DN to each antenna beam # 1 to #N from the first communication device
A wireless communication method that is designed to be transmitted at. 3. The wireless communication method according to claim 1, wherein the transmission path coefficient information generating procedure includes a pilot signal transmitted from each antenna beam from the first communication device and each second communication device. The first procedure for acquiring information indicating the relationship with the signal corresponding to the pilot signal received by each second communication device, and the above information acquired by each second communication device Radio communication having a second procedure of notifying the first communication apparatus from the second communication apparatus, and a third procedure of generating transmission path coefficient information based on the notified information in the first communication apparatus Method. 4. The wireless communication method according to claim 1, wherein the transmission path coefficient information generation procedure sets the pilot signal Pk to the pilot signal Pk based on the level of the pilot signal Pk transmitted from the first communication device. The level Aki of the corresponding received signal in the second communication device i is obtained, and the reception timing of the corresponding received signal in the second communication device i with respect to the transmission timing of the pilot signal Pk from the first communication device is determined. The delay time Tk is obtained, and the level Ak of the received signal and the delay time Tk are the signals corresponding to the pilot signal Pk transmitted from the first communication device and the pilot signal Pk received by the second communication device. And the antenna beam # corresponding to the pilot signal Pk based on the information Ak and Tk.
A wireless communication method for generating the transmission path coefficient information hki representing the state of the transmission path between the first communication device and the second communication device i formed by k. 5. The radio communication method according to claim 4, wherein the transmission path coefficient information generating procedure is the pilot signal P.
The level Ak of the received signal at the second communication device i corresponding to k
And its delay time Tk, hki = Ak · exp (−j · 2π · f · Tk) f: first communication device and second communication device formed by antenna beam #k according to the frequency of the pilot signal A wireless communication method for obtaining transmission line coefficient information hki representing the state of the transmission line between the i and i. 6. The wireless communication method according to claim 1, wherein the transmission path coefficient information generation procedure is performed when each second communication device i receives a plurality of signals corresponding to a pilot signal Pk. , The reception level Aks of each signal is obtained with reference to the level of the pilot signal, and the delay time Tks of each reception signal in the second communication device with respect to the transmission timing of the pilot signal from the first communication device. And the reception level Aks and the delay time Tks of each reception signal in the second communication device i obtained as described above are used for the pilot signal Pk transmitted from the first communication device and the second communication device i. A wireless communication method in which the transmission path coefficient information is generated based on the information indicating the relationship between the received pilot signal and the corresponding signal. 7. The wireless communication method according to claim 6, wherein the transmission path coefficient information generating procedure is the pilot signal P.
Using the level Aks of each received signal and its delay time Tks in the second communication device i corresponding to k, n: number of signals corresponding to pilot signal Pk arriving at the second communication device (2 or more) Aks: sth reception level Tks: s of signal corresponding to pilot signal Pk arriving at the second communication device i Second, the delay time f of the signal corresponding to the pilot signal Pk arriving at the second communication device i: the first communication device and the second communication device i formed by the antenna beam #k according to the frequency of the pilot signal A wireless communication method for obtaining transmission line coefficient information hki representing the state of the transmission line between the two. 8. The wireless communication method according to claim 1, wherein before transmitting each pilot signal from the first communication device,
There is a reference signal transmission procedure for transmitting a reference signal from the first communication device, and the pilot signal transmission procedure is such that each pilot signal is transmitted from the first communication device in a predetermined time relationship with the transmission timing of the reference signal. However, the transmission path coefficient information generation procedure, when receiving a signal corresponding to the reference signal and the pilot signal in each second communication device, the reception level of the signal corresponding to the pilot signal In addition to obtaining the reception level of the signal corresponding to the reference signal as a reference, the delay time of the reception timing of the signal corresponding to each pilot signal with respect to the reception timing of the signal corresponding to the reference signal is obtained, and corresponding to each pilot signal The level and delay time of the received signal and the pilot signal transmitted from the first communication device and the second communication A wireless communication method, wherein information indicating a relationship with a signal corresponding to the pilot signal received by the device is used, and the transmission path coefficient information is generated based on the information. 9. The wireless communication method according to claim 8, wherein the transmission path coefficient information generation procedure is performed when the second communication device receives a plurality of signals corresponding to the reference signal at different timings. One signal is selected from the plurality of signals, the received signal level corresponding to each pilot signal is obtained with reference to the received level of the selected signal, and each pilot for the reception timing of the selected signal A wireless communication method for obtaining a delay time of a reception timing of a reception signal corresponding to a signal. 10. The wireless communication method according to claim 8 or 9, wherein the transmission path coefficient information generation procedure is performed when the second communication device receives a plurality of signals corresponding to the pilot signal at different timings. , The reception level of each reception signal is determined with reference to the reception level of the reception signal corresponding to the reference signal, and the reception timing of each reception signal corresponding to the pilot signal with respect to the reception timing of the reception signal corresponding to the reference signal The delay time is calculated, and the reception level and delay time of each reception signal corresponding to the pilot signal are corresponded to the pilot signal transmitted from the first communication device and the pilot signal received by the second communication device. Wireless communication method in which the transmission path coefficient information is generated based on the information indicating the relationship with the signal . 11. The wireless communication method according to claim 1, wherein in the transmission path coefficient information generation procedure, a plurality of signals corresponding to respective pilot signals are received at different timings in each second communication device. At this time, there is a combined reception signal generation procedure for generating a combined reception signal that is time-equalized and combined so that each reception signal corresponding to each pilot signal is shifted on the time axis to be received at a predetermined same time, A wireless communication method for generating transmission path coefficient information based on information representing a relationship between each pilot signal and a corresponding combined reception signal. 12. The wireless communication method according to claim 11, wherein the combined reception signal generation procedure is performed so that the reception quality of a pilot signal to be transmitted to the second communication device satisfies a predetermined condition. A wireless communication method having a weight generation procedure for generating a weight for each received signal corresponding to a signal, and performing weighted synthesis of each received signal using the weight together with the time equalization to generate a synthetic received signal. 13. The wireless communication method according to claim 11 or 12, wherein the transmission path coefficient information generating step determines a combined reception level of the combined reception signal from a pilot signal transmitted from the first communication device and a second The transmission channel coefficient information is generated based on the combined reception level and the predetermined same time used in the time equalization, as information indicating the relationship with the signal corresponding to the pilot signal received by the communication device. Wireless communication method. 14. The wireless communication method according to claim 1, wherein the transmission path coefficient information generation procedure is based on a reception quality at each second communication device among pilot signals corresponding to each antenna beam. A radio communication method in which a pilot signal is selected and the transmission path coefficient information is generated based on information indicating a relationship between the selected pilot signal and a corresponding received signal. 15. The radio communication method according to claim 2, wherein the transmission path coefficient information generation procedure is performed for each antenna beam #k.
Of the pilot signals corresponding to
A predetermined number (n) of pilot signals are selected based on the reception quality at, and each of the selected pilot signals Pk (1 to
n) and the received signal corresponding to the pilot signal Pk based on the information indicating the relationship between the first communication device and the second communication device i with the antenna beam #k corresponding to the pilot signal Pk. A transmission line coefficient element hki representing the state of the formed transmission line is obtained, and the transmission line coefficient elements hki corresponding to the respective pilot signals Pk are concentrated in the diagonal region, and the transmission line coefficient matrix [H ] Is generated as transmission path coefficient information. 16. The wireless communication method according to claim 1, wherein the number M of antenna beams formed by the first communication device.
Is greater than the number N of the second communication devices, and the transmission path coefficient information generation procedure is the same as the pilot signal transmitted by each antenna beam #k (k = 1 to M) from the first communication device. , The transmission signals D1 to # 1 from the antenna beams # 1 to #M based on the information indicating the relationship with the reception signal at each second communication device i (i = 1 to N) corresponding to the pilot signal Pk. The relationship between DM and the received signals R1 to RN in each of the second communication devices 1 to N is [R] = [H] · [D] [R]: 1 × N matrix [D] consisting of elements R1 to RN. : 1 × M matrix consisting of elements D1 to DM [H]: M × N matrix consisting of elements hki (k = 1 to M, i =
1 to N), a transmission channel coefficient matrix [H] is generated as transmission channel coefficient information, and the conversion operator calculation procedure is [T] = [H] · [Z] [Z]: N × M Matrix [T]: A conversion operator represented by a matrix [Z] defined by an N × N matrix in which components other than diagonal components are zero is calculated, and the signal conversion procedure is performed in each second communication. The signals [S] = S1 to SN to be transmitted to the devices 1 to N are transmitted by the respective antenna beams # 1 to #M according to [D] = [Z] · [S] [D] = D1 To DM, and the above signal transmission procedure is performed by the signal D1 obtained by the above conversion.
DM from the first communication device to each antenna beam # 1 to #M
A wireless communication method that is designed to be transmitted at. 17. The wireless communication method according to claim 16, wherein the conversion operator calculation procedure takes into consideration the condition that the reception signal Ri in each second communication device i is maximum. A wireless communication method in which each element of the matrix [Z] is calculated. 18. The wireless communication method according to claim 16 or 17, wherein the transmission path coefficient information generating procedure is performed when each second communication device i receives a signal RiPk corresponding to each pilot signal Pk. A first procedure of calculating each element hki (k = 1 to M) of the i-th row in the transmission path coefficient matrix [H] based on the information indicating the relationship between the signal RiPk and the pilot signal Pk, and each first A second procedure for notifying the first communication device of each element hki of the above i-th line from the second communication device i, and an i-th line notified from each second communication device i in the first communication device And a third procedure for generating the transmission channel coefficient matrix [H] by using each element hki of the above. 19. The wireless communication method according to claim 16, wherein the transmission path coefficient information generation procedure is performed for each antenna beam #k.
Of the pilot signals corresponding to
A predetermined number (n) of pilot signals are selected based on the reception quality at, and each of the selected pilot signals Pk (k =
1 to n) and the pilot signal Pk based on the information indicating the relationship between the pilot signal Pk and the received signal corresponding to the pilot signal Pk.
The transmission line coefficient element hki representing the state of the transmission line formed between the first communication device and the second communication device i is obtained by the antenna beam #k corresponding to the above, and the transmission corresponding to each pilot signal Pk is obtained. A wireless communication method in which a channel coefficient element hki is concentrated in a diagonal region and a channel coefficient matrix [H] in which other elements are zero is generated as channel coefficient information. 20. The wireless communication method according to claim 1, wherein each second communication device adjusts an antenna pattern to receive each pilot signal with a substantially omnidirectional antenna pattern. Then, select the pilot signal with the best reception quality from the received pilot signals, adjust the directivity of the antenna pattern so that the reception quality of the selected pilot signal satisfies the specified condition, and then adjust it. A wireless communication method for performing the processing in the above-mentioned transmission path coefficient information generation procedure using the directional antenna pattern. 21. In a wireless communication system for wirelessly communicating between a first communication device having a plurality of antennas and a plurality of second communication devices, each of the plurality of antenna beams from the first communication device. Pilot signal transmission control means for transmitting a pilot signal corresponding to an antenna beam to the plurality of second communication devices, a pilot signal transmitted by each antenna beam from the first communication device, and each second communication device Represents the state of the transmission path between the first communication device and the second communication device formed by each antenna beam based on the information indicating the relationship with the signal corresponding to the pilot signal received in Transmission line coefficient information generating means for generating transmission line coefficient information, and transmission to be transmitted by each antenna beam obtained by converting a signal to be transmitted to each second communication device with a conversion operator A conversion operator that calculates the conversion operator based on the transmission path coefficient information so that the received signal at each second communication device becomes the signal to be transmitted when the signal is transmitted by each antenna beam. A calculating means, a signal converting means for converting a signal to be transmitted to each second communication device into a transmitting signal to be transmitted by each antenna beam using the conversion operator, and a transmitting signal obtained by the conversion. A wireless communication system having a signal transmission control unit that causes each antenna beam to transmit from a first communication device. 22. The wireless communication system according to claim 21, wherein the number of antenna beams formed by the first communication device is
The number is the same as the number N of the second communication devices, and the transmission path coefficient information generating means includes the pilot signal Pk transmitted from each of the antenna beams #k (k = 1 to N) from the first communication device, The transmission signals D1 to DN from the antenna beams # 1 to #N are based on the information indicating the relationship with the reception signal at each second communication device i (i = 1 to N) corresponding to the pilot signal Pk. And the received signals R1 to RN at the respective second communication devices 1 to N, [R] = [H] · [D] [R]: 1 × N matrix [D] consisting of elements R1 to RN: 1 × N matrix [H] consisting of elements D1 to DN: N × N matrix (k, i = 1 to N) consisting of elements hki is generated as channel coefficient information. , The conversion operator calculation means is the transmission line coefficient matrix [H]
The conversion operator represented by the inverse matrix [H] ⁻¹ of the above is calculated, and the signal conversion means converts the signals [S] = S1 to SN to be transmitted to the respective second communication devices 1 to N into [D ] = [H] ^-1 · [S], the signals to be transmitted by the respective antenna beams # 1 to #N are converted into [D] = D1 to DN, and the signal transmission control means is obtained by the above conversion. Signal D
1 to DN from the first communication device to each antenna beam # 1 to #
A wireless communication system adapted to transmit at N. 23. The wireless communication system according to claim 21 or 22, wherein the transmission path coefficient information generating means is provided in each second communication device, and is transmitted from each first communication device by each antenna beam. First means for acquiring information indicating the relationship between the pilot signal and the signal corresponding to the pilot signal received by the second communication device, and each second communication device, the first means Second means for notifying the first communication device from the second communication device of the information acquired by the means, and information provided to the first communication device and notified to the first communication device And a third means for generating transmission path coefficient information based on the above. 24. The radio communication system according to claim 21, wherein the transmission path coefficient information generating means sets the pilot signal Pk to the pilot signal Pk based on the level of the pilot signal Pk transmitted from the first communication device. Reception level acquisition means for obtaining the level Aki of the corresponding reception signal in the second communication device i, and the corresponding reception signal in the second communication device i with respect to the transmission timing of the pilot signal Pk from the first communication device i. And a delay time acquisition means for obtaining a delay time Tk of the reception timing of the received signal, the level Ak of the received signal and the delay time Tk being transmitted to the pilot signal Pk transmitted from the first communication device and the second communication device. The information corresponding to the signal corresponding to the pilot signal Pk received by the antenna is used, and the antenna corresponding to the pilot signal Pk is based on the information Ak and Tk. beam#
A wireless communication system configured to generate the transmission path coefficient information hki representing the state of the transmission path between the first communication device and the second communication device i formed by k. 25. The radio communication system according to claim 24, wherein the transmission path coefficient information generating means is the pilot signal P.
The level Ak of the received signal at the second communication device i corresponding to k
And its delay time Tk, hki = Ak · exp (−j · 2π · f · Tk) f: first communication device and second communication device formed by antenna beam #k according to the frequency of the pilot signal A wireless communication system adapted to obtain transmission line coefficient information hki representing the state of the transmission line between the transmission line i and i. 26. The radio communication system according to any one of claims 21 to 23, wherein the transmission path coefficient information generating means receives a plurality of signals corresponding to the pilot signal Pk in each second communication device i. Reception level acquisition means for obtaining the reception level Aks of each signal with reference to the level of the pilot signal, and each reception signal at the second communication device with respect to the transmission timing of the pilot signal from the first communication device. Delay time obtaining means for obtaining the delay time Tks of the pilot signal transmitted from the first communication device and the reception level Aks and the delay time Tks of each received signal in the second communication device i obtained as described above. Information indicating a relationship between Pk and a signal corresponding to the pilot signal received by the second communication device i, and the transmission path is based on the information. Wireless communication system to generate information on the number. 27. The radio communication system according to claim 26, wherein said transmission path coefficient information generating means is said pilot signal P.
Using the level Aks of each received signal and its delay time Tks in the second communication device i corresponding to k, n: number of signals corresponding to pilot signal Pk arriving at the second communication device (2 or more) Aks: sth reception level Tks: s of signal corresponding to pilot signal Pk arriving at the second communication device i Second, the delay time f of the signal corresponding to the pilot signal Pk arriving at the second communication device i: the first communication device and the second communication device i formed by the antenna beam #k according to the frequency of the pilot signal A wireless communication system adapted to obtain transmission line coefficient information hki representing the state of the transmission line between the two. 28. The radio communication system according to claim 21, wherein before transmitting each pilot signal from the first communication device,
It has a reference signal transmission control means for transmitting a reference signal from the first communication device, wherein the pilot signal transmission means transmits each pilot signal from the first communication device in a predetermined time relationship with the transmission timing of the reference signal. The transmission path coefficient information generating means, when receiving the signal corresponding to the reference signal and the signal corresponding to each pilot signal in each second communication device, the reception level of the signal corresponding to the pilot signal And a reception level obtaining means for obtaining the reception timing of the signal corresponding to the reference signal as a reference, and a delay time for obtaining a delay time of the reception timing of the signal corresponding to each pilot signal with respect to the reception timing of the signal corresponding to the reference signal. Acquiring means for obtaining the level and delay time of the received signal corresponding to each of the pilot signals. The information indicating the relationship between the pilot signal transmitted from the receiving device and the signal corresponding to the pilot signal received by the second communication device, and the transmission path coefficient information is generated based on the information. Wireless communication system. 29. The radio communication system according to claim 28, wherein the transmission path coefficient information generating means receives a plurality of signals corresponding to the reference signal at different timings in the second communication device, It has a reference signal selection means for selecting one signal from the plurality of signals, and the reception level acquisition means obtains the level of the reception signal corresponding to each pilot signal with reference to the reception level of the selected signal. At the same time, the delay time acquisition means obtains the delay time of the reception timing of the reception signal corresponding to each pilot signal with respect to the reception timing of the selected signal. 30. The radio communication system according to claim 28 or 29, wherein the reception level acquisition means receives each of a plurality of signals corresponding to the pilot signal at different timings in the second communication device. The reception level of the reception signal is obtained by using the reception level of the reception signal corresponding to the reference signal as a reference, and the delay time acquisition means is provided for each reception signal corresponding to the reception timing of the reception signal corresponding to the reference signal. The delay time of the reception timing is calculated, and the reception level and the delay time of each reception signal corresponding to the pilot signal are received by the pilot signal transmitted from the first communication device and the second communication device. Information representing the relationship with the signal corresponding to the pilot signal is generated, and the transmission path coefficient information is generated based on that information. Unishi was radio communication system. 31. The radio communication system according to any one of claims 21 to 23, wherein the transmission path coefficient information generating means receives a plurality of signals corresponding to respective pilot signals at different timings in each second communication device. At this time, the received signal corresponding to each pilot signal is shifted on the time axis, time-equalized so as to receive at a predetermined same time, and has a combined reception signal generating means for generating a combined reception signal that is combined, A wireless communication system configured to generate transmission path coefficient information based on information indicating a relationship between each pilot signal and a corresponding combined reception signal. 32. The radio communication system according to claim 31, wherein the combined reception signal generating means has a pilot signal to be transmitted to the second communication device so that the reception quality of the pilot signal satisfies a predetermined condition. A wireless communication system comprising weight generating means for generating a weight for each received signal corresponding to a signal, wherein the received signals are weighted and combined using the weights together with the time equalization to generate a combined received signal. 33. The wireless communication system according to claim 31 or 32, wherein said transmission path coefficient information generating means sets a combined reception level of the combined reception signal to a pilot signal transmitted from said first communication device and a second reception signal. The transmission channel coefficient information is generated based on the combined reception level and the predetermined same time used in the time equalization, as information indicating the relationship with the signal corresponding to the pilot signal received by the communication device. Wireless communication system. 34. The radio communication system according to claim 21, wherein said transmission path coefficient information generating means is based on reception quality at each second communication device among pilot signals corresponding to each antenna beam. A wireless communication system having pilot selecting means for selecting a pilot signal, and generating the transmission path coefficient information based on information representing a relationship between the selected pilot signal and a corresponding received signal. 35. The radio communication system according to claim 32, wherein the transmission path coefficient information generating means is arranged to transmit each antenna beam #k.
Of the pilot signals corresponding to
The pilot selecting means for selecting a predetermined number (n) of pilot signals based on the reception quality at 1, and the relationship between each of the selected pilot signals Pk (1 to n) and the received signal corresponding to the pilot signal Pk. The first communication device and the second communication device i using the antenna beam #k corresponding to the pilot signal Pk on the basis of the indicated information.
And a transmission line coefficient element generating means for obtaining a transmission line coefficient element hki representing the state of the transmission line formed between the transmission line coefficient element hki and the transmission line coefficient element hki corresponding to each pilot signal Pk. A wireless communication system in which a channel coefficient matrix [H] in which other elements are zero is generated as channel coefficient information. 36. The radio communication system according to claim 21, wherein the number M of antenna beams formed by the first communication device.
Is greater than the number N of the second communication devices, and the transmission path coefficient information generating means uses the pilot signals transmitted by the antenna beams #k (k = 1 to M) from the first communication device. , The transmission signals D1 to # 1 from the antenna beams # 1 to #M based on the information indicating the relationship with the reception signal at each second communication device i (i = 1 to N) corresponding to the pilot signal Pk. The relationship between DM and the received signals R1 to RN in each of the second communication devices 1 to N is [R] = [H] · [D] [R]: 1 × N matrix [D] consisting of elements R1 to RN. : 1 × M matrix consisting of elements D1 to DM [H]: M × N matrix consisting of elements hki (k = 1 to M, i =
1 to N), a transmission channel coefficient matrix [H] is generated as transmission channel coefficient information, and the conversion operator calculation means is [T] = [H] · [Z] [Z]: N × M Matrix [T]: A conversion operator represented by a matrix [Z] defined by an N × N matrix in which components other than the diagonal components are zero, and the signal conversion unit is configured to perform the second communication. The signals [S] = S1 to SN to be transmitted to the devices 1 to N are transmitted by the respective antenna beams # 1 to #M according to [D] = [Z] · [S] [D] = D1 To DM, and the signal transmission control means converts the signal D obtained by the conversion.
1 to DM from the first communication device to each antenna beam # 1 to #
A wireless communication system adapted to transmit at M. 37. The wireless communication system according to claim 36, wherein the conversion operator calculation means takes into consideration the condition that the reception signal Ri in each second communication device i becomes maximum. A wireless communication system configured to calculate each element of a matrix [Z] such that 38. The radio communication system according to claim 36, wherein the transmission path coefficient information generating means is provided in each second communication device i, and the second communication device i corresponds to each pilot signal Pk. When the signal RiPk is received, each element hki of the i-th row in the transmission channel coefficient matrix [H] is based on the information indicating the relationship between the received signal RiPk and the pilot signal Pk.
First means for calculating (k = 1 to M) and each second communication device i are provided, and the second communication device i notifies each element hki of the i-th row to the first communication device. And a second means for generating the above-mentioned transmission line coefficient matrix [H] using each element hki of the i-th row provided in the first communication device and notified from each second communication device i. And a wireless communication system. 39. The radio communication system according to any one of claims 36 to 38, wherein the transmission path coefficient information generating means is arranged to transmit each antenna beam #k.
Of the pilot signals corresponding to
Of pilot signals for selecting a predetermined number (n) of pilot signals based on the reception quality at 1, and the selected pilot signals Pk (k = 1 to n) and the reception signals corresponding to the pilot signals Pk. A transmission line coefficient element hki representing the state of the transmission line formed between the first communication device and the second communication device i by the antenna beam #k corresponding to the pilot signal Pk based on the information indicating the relationship. A transmission line coefficient element [H] in which the transmission line coefficient elements hki corresponding to each pilot signal Pk are concentrated in the diagonal region and the other elements are zero. A wireless communication system configured to generate as coefficient information. 40. The radio communication system according to any one of claims 21 to 39, wherein each pilot signal is provided in each of the second communication devices and the antenna pattern is adjusted so that each pilot signal is generated by a substantially omnidirectional antenna pattern. The first antenna control means for receiving and the pilot signal with the best reception quality among the received pilot signals are selected, and the antenna pattern of the above antenna pattern is selected so that the reception quality of the selected pilot signals satisfies a predetermined condition. A wireless communication system comprising: a second antenna control means for adjusting directivity, and performing the processing by the transmission path coefficient information generating means with an antenna pattern of directivity adjusted by the second antenna control means. 41. In a communication device having a plurality of antennas and performing wireless communication with a plurality of partner communication devices, a plurality of pilot beams corresponding to the respective antenna beams are transmitted by a plurality of antenna beams. When the pilot signal transmitting means for transmitting to each of the antennas and the information indicating the relationship between each pilot signal and its received signal are received from each partner communication device after transmitting the pilot signal, each antenna beam is transmitted based on the information. Transmission coefficient information generating means for generating transmission path coefficient information representing the state of the transmission path between the communication apparatus and each of the partner communication apparatuses, and a conversion operation of a signal to be transmitted to each of the partner communication apparatuses. When the transmission signal to be transmitted by each antenna beam obtained by conversion by the slave is transmitted by each antenna beam, the reception signal at each partner communication device is transmitted A conversion operator calculating means for calculating the conversion operator that becomes a power signal based on the transmission path coefficient information, and a signal to be transmitted to each partner communication device by using the conversion operator in each antenna beam. A communication device having signal conversion means for converting into a transmission signal to be transmitted, and signal transmission means for transmitting the transmission signal obtained by the conversion with each antenna beam. 42. The communication device according to claim 41, wherein the number of antenna beams is the same as the number N of the partner communication devices, and the channel coefficient information generating means receives each of the partner communication devices. Pilot signal Pk transmitted by antenna beam #k (k = 1 to N) and its pilot signal Pk
Based on the information indicating the relationship with the reception signal at each second communication device i (i = 1 to N) corresponding to the above, the transmission signals D1 to DN from each antenna beam # 1 to #N and each second Communication device 1
The relationship between the received signals R1 to RN at [N] to [N] is [R] = [H] · [D] [R]: 1 × N matrix consisting of elements R1 to RN [D]: 1 × consisting of elements D1 to DN N matrix [H]: A channel coefficient matrix [H] represented as N × N matrix (k, i = 1 to N) consisting of elements hki is generated as channel coefficient information, and the conversion operator calculation means is , Above channel coefficient matrix [H]
The conversion operator represented by the inverse matrix [H] ⁻¹ of the above is calculated, and the signal conversion means [D] = signals [S] = S1 to SN to be transmitted to the partner communication devices 1 to N, [D] = According to [H] ^-1 · [S], the signals to be transmitted by the antenna beams # 1 to #N are converted into [D] = D1 to DN, and the signal transmitting means is the signal obtained by the above conversion. D1 ~
A communication device configured to transmit DN by each antenna beam # 1 to #N. 43. The communication device according to claim 41, wherein the number M of antenna beams is larger than the number N of the partner communication devices, and the transmission path coefficient information generating means is received from each partner communication device. Information indicating the relationship between the pilot signal transmitted by each antenna beam #k (k = 1 to M) and the received signal at each partner communication device i (i = 1 to N) corresponding to the pilot signal Pk Based on each antenna beam # 1
~ Transmission signals D1 ~ DM from #M and each second communication device 1 ~
The relationship between the received signals R1 to RN at N is [R] = [H] · [D] [R]: 1 × N matrix consisting of elements R1 to RN [D]: 1 × M consisting of elements D1 to DM Matrix [H]: M × N matrix (k = 1 to M, i =
1 to N), a transmission channel coefficient matrix [H] is generated as transmission channel coefficient information, and the conversion operator calculation means is [T] = [H] · [Z] [Z]: N × M Matrix [T]: A conversion operator represented by a matrix [Z] defined by an N × N matrix in which components other than the diagonal components are zero, and the signal conversion unit is configured to perform the second communication. The signals [S] = S1 to SN to be transmitted to the devices 1 to N are transmitted by the respective antenna beams # 1 to #M according to [D] = [Z] · [S] [D] = D1 To DM, and the signal transmitting means converts the signal D1 obtained by the above conversion.
A wireless communication device configured to transmit DM by each antenna beam # 1 to #M. 44. The communication device according to claim 43, wherein the conversion operator calculation means takes the condition that the reception signal Ri in each of the other communication devices i becomes maximum, into a matrix which becomes the conversion operator. A communication device configured to calculate each element of [Z]. 45. In a communication device for performing wireless communication with a predetermined communication device having a plurality of antennas, a pilot signal corresponding to each antenna beam is transmitted by the plurality of antenna beams from the predetermined communication device. In this case, the communication device has first means for generating information indicating the relationship between each pilot signal and a received signal corresponding to the pilot signal, and second means for notifying the predetermined communication device of the information. . 46. The communication device according to claim 45, wherein the first means uses the level of the pilot signal Pk transmitted from the predetermined communication device as a reference, and the level Aki of the received signal corresponding to the pilot signal Pk. And a delay time obtaining means for obtaining a delay time Tk of the reception timing of the corresponding reception signal in the communication device with respect to the transmission timing of the pilot signal Pk from the predetermined communication device. The second means uses the level Ak and the delay time Tk of the received signal as the information indicating the relationship between the pilot signal Pk transmitted from the predetermined communication device and the received signal corresponding to the pilot signal Pk. Communication device adapted to notify the other communication device. 47. The communication device according to claim 45, wherein when the first means receives a plurality of signals corresponding to a pilot signal Pk, the reception level Aks of each signal is set to the level of the pilot signal. And a delay time acquisition unit for obtaining a delay time Tks of each reception signal in the communication device with respect to a transmission timing of the pilot signal from the predetermined communication device. The second means represents the relationship between the reception level Aks and the delay time Tks of each reception signal obtained as described above, between the pilot signal Pk transmitted from the predetermined communication device and the reception signal corresponding to the pilot signal Pk. A communication device configured to notify the predetermined communication device as information. 48. The communication apparatus according to claim 45, wherein, before transmitting each pilot signal from the predetermined communication apparatus, the reference signal is transmitted from the communication apparatus in a predetermined relationship with the transmission timing of each pilot signal. In this case, the first means is a reception level acquisition means for obtaining the reception level of the reception signal corresponding to the pilot signal with reference to the reception level of the reception signal corresponding to the reference signal, and the reception signal corresponding to the reference signal. A delay time obtaining means for obtaining the delay time of the reception timing of the reception signal corresponding to each pilot signal with respect to the reception timing of, and the second means, the level and delay time of the reception signal corresponding to each pilot signal Corresponds to the pilot signal transmitted from the specified communication device and the pilot signal received by the communication device A communication device configured to notify the predetermined communication device as information indicating a relationship with the signal. 49. The communication device according to claim 48, wherein when the communication device receives a plurality of signals corresponding to the reference signal at different timings, the first means extracts the plurality of signals from the plurality of signals. And a reference signal selection means for selecting one signal, wherein the reception level acquisition means obtains a reception signal level corresponding to each pilot signal with reference to the reception level of the selected signal, and acquires the delay time. The means is for obtaining a delay time of the reception timing of the reception signal corresponding to each pilot signal with respect to the reception timing of the selected signal. 50. The communication device according to claim 45, wherein the first means corresponds to each pilot signal when the communication device receives a plurality of signals corresponding to each pilot signal at different timings. The received signal is shifted on the time axis and time-equalized so as to be received at a predetermined same time, and combined reception signal generating means for generating a combined reception signal is generated. And a communication device configured to notify the predetermined communication device of information indicating a relationship between the corresponding received signal and the received signal. 51. The communication device according to claim 50, wherein the combined reception signal generating means responds to the pilot signal so that the reception quality of the pilot signal to be transmitted to the communication device satisfies a predetermined condition. A communication device comprising weight generating means for generating a weight for each received signal, wherein the received signals are weighted and combined using the weight together with the time equalization to generate a combined received signal. 52. The communication apparatus according to claim 50 or 51, wherein the first means receives the combined reception level of the combined reception signal and the pilot signal transmitted from the predetermined communication apparatus by the communication apparatus. A communication device which is acquired as information indicating a relationship with a signal corresponding to the pilot signal. 53. The communication device according to any one of claims 45 to 52, further comprising: first antenna control means for adjusting the antenna pattern to receive each pilot signal with the substantially omnidirectional antenna pattern; Second antenna control means for selecting the pilot signal with the best reception quality from the received pilot signals and adjusting the directivity of the antenna pattern so that the reception quality of the selected pilot signal satisfies a predetermined condition And a communication device that performs processing by the first means with a directional antenna pattern adjusted by the second antenna control means.