JP2020137054A - Wireless communication system, wireless communication method and terminal station device - Google Patents

Abstract

To improve frequency use efficiency in a wireless communication system, in which a base station dynamically sets a spatial multiplex transmission band based on the number of relay stations receivable by a terminal station, by sharing an identical frequency band by a plurality of relay stations under the Doppler shift environment of the relay stations.SOLUTION: A terminal station device of the wireless communication system includes: frequency error detection means which, on receipt of a downlink control signal which is superposed to an identical frequency band and transmitted from the base station through a plurality of relay stations, detects the frequency error of the downlink control signal based on machine learning obtained by inputting the received waveform information of the control signal, the transmission signal information acquired in advance and peripheral information; and relay station selection means which performs the frequency synchronization of the downlink control signal based on the frequency error, and estimates channel information between each relay station and the terminal station from the frequency-synchronized downlink control signal, to select one or more receivable relay stations based on the channel information to notify the base station of the selected one.SELECTED DRAWING: Figure 1

Description

The present invention is composed of one base station, a plurality of moving relay stations, and a plurality of terminal stations, and performs downlink multiplex connection via one or more relay stations to which the base station and each terminal station can be connected. Related to wireless communication systems, wireless communication methods and terminal station devices.

The low earth orbit satellite (LEO) system uses a satellite with a lower orbit (800 to 2000 km) than the geostationary satellite to communicate, and is compared with the geostationary satellite (GEO) system in the geostationary orbit (altitude of about 36,000 km). Therefore, it has the advantage that the characteristics of communication are low delay and low attenuation. In addition, MIMO (Multi-Input Multi-Output) transmission by a terminal having a plurality of LEO satellite signals and a plurality of receiving antennas can improve the communication capacity as compared with the case of a single LEO satellite.

On the other hand, since the received signal is affected by the Doppler shift due to the movement of the LEO satellite, in MIMO transmission using a plurality of LEO satellites, the Doppler shift of each LEO satellite is estimated individually, and each satellite-specific control signal It is necessary to allocate a unique frequency band that can be separated from each other. Therefore, the system bandwidth is reduced, and the communication capacity of the LEO-MIMO system is reduced.

Non-Patent Document 1 discloses a downlink control method that performs dynamic MIMO transmission and frequency allocation from a plurality of satellites in a Doppler shift environment for the purpose of improving the frequency utilization efficiency of a low earth orbit (LEO) satellite system. .. Here, the control signal of the downlink signal from the satellite and the data signal are arranged at different frequencies, and the control signal of the satellite that can be received within the service area is set to be assigned to a different frequency band. The terminal synchronizes using control signals from a plurality of satellites and grasps the satellites that can be received and the number of satellites. Furthermore, channel estimation is performed using control signals, and information on a plurality of target satellites for MIMO transmission based on estimation information with all receivable satellites is notified to the base station via an uplink. The base station that receives the notification from the terminal performs MIMO transmission to the terminal using the plurality of satellites. The base station sets a unique MIMO band as a data signal band based on the number of receivable satellites of each terminal station, and starts transmission to each satellite. Further, the base station notifies the control signal of each satellite of the frequency, bandwidth, and satellite information of the data signal of each satellite. It is assumed that the control signal and the data signal transmitted via each satellite are generated from the same baseband signal and are synchronized. The terminal receives the data signal and performs equalization processing according to the notified information to demodulate the data. From the channel estimation information of the control signal, a weight matrix for equalizing the MIMO signal is calculated, and the signals of each satellite are separated and demodulated.

D. Goto, H. Shibayama, F. Yamashita, R. Okema and T. Yamazato, "LEO-MIMO Satellite Systems for High Capacity Transmission", IEEE GLOBECOM 2018, Dec 2018. Tabakovic, Z., “Doppler effect in non-GSO satellite propagation.” In Millennium conference on antennas and propagation-IEEE AP-2000., 2000.

The method of Non-Patent Document 1 shifts the control signals of satellites that can be received within the same service area to different frequency bands in order to prevent false detection of signals due to frequency asynchronous signal reception due to different Doppler shifts of each satellite. It is set to be assigned. In this case, since the control signal increases as the number of satellites increases, there is a concern that the frequency utilization efficiency may deteriorate. Therefore, even when MIMO transmission by a plurality of satellites is performed, there is a problem that the transmission capacity cannot be expected to be improved due to the increase in control signals. Even if the number of satellites increases, a method that can improve the channel capacity of MIMO without deterioration of frequency utilization efficiency is desirable.

The present invention is a wireless communication system in which a base station dynamically sets a spatial multiplex transmission band based on the number of receivable relay stations of a terminal station, and is the same for a plurality of relay stations under a Doppler shift environment of the relay stations. An object of the present invention is to provide a wireless communication system, a wireless communication method, and a terminal station device capable of sharing a frequency band and improving frequency utilization efficiency.

The first invention includes one base station, a plurality of mobile relay stations, and a plurality of terminal stations in a service area. The base stations are based on the positions of the plurality of relay stations, and each relay station has its own position. A relay station that can receive the signal to be transmitted is identified in the service area, and the data signal is frequency-multiplexed to each terminal station via the relay station in a different frequency band, and the terminal station corresponding to the spatial multiplex transmission. It is equipped with a downlink multiplex connection means for spatially multiplex transmission of data signals via a specific frequency band and multiple relay stations, and a downlink multiplex connection from a base station to each terminal station via multiple relay stations. In the wireless communication system that performs the above, the downlink multiplex connection means of the base station includes means for transmitting a downlink control signal including a relay station ID in the same frequency band from a plurality of relay stations that can be received in the service area, and includes a terminal station. Receives downlink control signals superimposed on the same frequency band, inputs the received waveform information, transmission signal information acquired in advance, and peripheral information, and detects the frequency error of the downlink control signal based on the result of machine learning. Then, frequency synchronization of the downlink control signal is performed based on the frequency error, channel information between the relay station and the terminal station is estimated from the frequency-synchronized downlink control signal, and reception is possible based on the channel information. It is provided with a downlink multiple connection means for selecting one or more relay stations and notifying the base station, and the downlink multiple connection means of the base station is data addressed to the terminal station via the relay station selected by the terminal station. It includes means for allocating a specific frequency band for spatial multiplex transmission of a signal, notifying the terminal station of the information by a downlink control signal, and spatially multiplexing a data signal addressed to the terminal station.

In the wireless communication system of the first invention, the downlink control signal and the data signal addressed to the terminal station are generated from the same baseband signal and synchronized, and the downlink multiplex connection means of the terminal station is estimated from the downlink control signal. Includes means for separating and demodulating spatially multiplexed data signals using channel information.

The second invention includes one base station, a plurality of moving relay stations, and a plurality of terminal stations in the service area, and the base station is based on the positions of the plurality of relay stations. A relay station that can receive the signal to be transmitted is identified in the service area, and the data signal is frequency-multiplexed to each terminal station via the relay station in a different frequency band, and the terminal station corresponding to the spatial multiplex transmission. It is equipped with a downlink multiplex connection means for spatially multiplex transmission of data signals via a specific frequency band and multiple relay stations, and a downlink multiplex connection from a base station to each terminal station via multiple relay stations. In the wireless communication method for performing the above, the downlink multiplex connection means of the base station performs a process of transmitting a downlink control signal including a relay station ID in the same frequency band from a plurality of relay stations that can be received in the service area, and the terminal station. The downlink multi-element connection means receives the downlink control signal superimposed on the same frequency band, inputs the received waveform information, the transmission signal information acquired in advance, and the peripheral information, and performs downlink control based on the result of machine learning. The frequency error of the signal is detected, the frequency of the downlink control signal is synchronized based on the frequency error, and the channel information between the relay station and the terminal station is estimated from the frequency-synchronized downlink control signal, and the channel is estimated. Based on the information, one or more receivable relay stations are selected and notified to the base station, and the downlink multiplex connection means of the base station is addressed to the terminal station via the relay station selected by the terminal station. Allocates a specific frequency band for spatial multiplex transmission of the data signal of the above, notifies the terminal station of the information by a downlink control signal, and performs a process of spatially multiplex transmission of the data signal addressed to the terminal station.

In the wireless communication method of the second invention, the downlink control signal and the data signal addressed to the terminal station are generated from the same baseband signal and synchronized, and the downlink multiplex connection means of the terminal station is estimated from the downlink control signal. Separation and demodulation of spatially multiplexed data signals are performed using channel information.

The third invention includes one base station, a plurality of moving relay stations, and a plurality of terminal stations in the service area, and the base station is based on the positions of the plurality of relay stations. A relay station that can receive the signal to be transmitted is identified in the service area, and the data signal is frequency-multiplexed to each terminal station via the relay station in a different frequency band, and the terminal station corresponding to spatial multiplex transmission is supported. It is equipped with a downlink multiplex connection means for spatially multiplex transmission of data signals via a specific frequency band and multiple relay stations, and a downlink multiplex connection from a base station to each terminal station via multiple relay stations. In the terminal station device of the wireless communication system that performs the above, the downlink control signal transmitted by superimposing on the same frequency band from the base station via a plurality of relay stations is received, and the received waveform information and the transmission signal acquired in advance are received. A frequency error detecting means that detects the frequency error of the downlink control signal based on the result of machine learning by inputting information and peripheral information, and frequency synchronization of the downlink control signal based on the frequency error are performed, and further frequency synchronization is performed. It is provided with a relay station selection means that estimates channel information between a relay station and a terminal station from the downlink control signal, selects one or more receivable relay stations based on the channel information, and notifies the base station. ..

According to the present invention, in a wireless communication system including a plurality of mobile relay stations, the base station dynamically sets the MIMO transmission band based on the number of receivable relay stations of the terminal station, so that a plurality of relay stations can be relayed as much as possible. It is possible to share the frequency band for spatial multiplex transmission at stations, and improvement in frequency utilization efficiency can be expected. In particular, the relay station sets the control signal of each relay station in the same frequency band, detects the frequency error (Doppler frequency) of the relay station, synchronizes the frequency of the downlink control signal, and estimates the channel information. Even if it increases, the deterioration of frequency utilization efficiency can be avoided.

It is a figure which shows the structural example of the wireless communication system of this invention. It is a figure which shows the configuration example of a base station 10. It is a figure which shows the structural example of the relay stations A, B, and C. It is a figure which shows the configuration example of the terminal stations 1, 2, and 3. It is a figure which shows the frame format of the downlink control signal. It is a figure which shows the frame format of the uplink control signal. It is a flowchart which shows the processing procedure example of the base station 10 and the terminal stations 1, 2, 3 in this invention.

<System configuration>
FIG. 1 shows a configuration example of the wireless communication system of the present invention.
In FIG. 1, the wireless communication system includes one base station 10, a plurality of mobile relay stations A, B, C, ..., X, and a plurality of terminal stations 1 (here, three) in a service area. A downlink that consists of a few and performs multiplex transmission to multiple terminal stations in the service area using the FDMA method, and MIMO (spatial multiplexing) transmission only to terminal stations that can be equalized and separated for each frequency band. It is a multiple connection configuration. Each terminal station has one or more antennas, and for the sake of simplicity, terminal stations 1, 2, and 3 each have one, two, and three antennas, and the terminal station 2 has two or more antennas. MIMO transmission is possible for, and 3.

In the downlink signal from the relay station, the control signal and the data signal are arranged in different frequency bands, the frequency band of the control signal is fixed and known to the terminal station, and the frequency bands W1, W2, and W3 of the data signal are active. Can be changed. Here, the alphabets of the relay stations A, B, C, the control signals A, B, C and the data signals A, B, C have a one-to-one correspondence, and the relay station A has the control signal A and the data signal A. Will be sent.

The base station 10 grasps the position information of the relay stations A to X, and identifies the receivable relay station in the service area based on the position of each relay station. Here, it is assumed that the signals transmitted by the three relay stations A, B, and C can be received within the service area. When the relay station is an artificial satellite that moves in a predetermined orbit, the base station 10 grasps the current position of each relay station from the orbit information. In the case of a relay station moving on the ground, the base station 10 obtains the position information acquired by each relay station using GPS or the like via the terrestrial network.

The base station 10 transmits control signals A, B, and C assigned to the same frequency band from relay stations A, B, and C that can be received in the service area. On the other hand, the terminal stations 1, 2, and 3 in the service area receive the receivable control signals among the control signals A, B, and C transmitted from the relay stations A, B, and C, perform synchronization processing, and receive each. Know the possible relay stations and their number. Further, a relay station (request relay station) that estimates channel information between the relay station and the terminal station using a synchronized control signal and requests MIMO transmission based on the receivable relay station and the channel information. ) Is notified to the base station 10 via an arbitrary uplink.

The base station 10 allocates a request relay station of each terminal station and a frequency band of a data signal, notifies each terminal station of the information by using a control signal, and starts MIMO transmission via the corresponding relay station. In the example of FIG. 1, the signal addressed to the terminal station 1 is transmitted from the relay station A in the frequency band W1. The signal addressed to the terminal station 2 is transmitted from the relay stations A and B in MIMO in the frequency band W2. The signal addressed to the terminal station 3 is transmitted from the relay stations A, B, and C in MIMO in the frequency band W3. The relay stations A, B, and C basically have only a function of relay-transmitting the signal received from the base station 10 to the terminal stations 1, 2, and 3 in a receivable state by performing frequency conversion and amplification. ..

Since the control signal and the data signal are generated from the same baseband signal, it is assumed that the signals are synchronized. Therefore, the data signal can also be synchronized by the synchronization using the control signal, and the terminal station receives and equalizes the data signal according to the notified information to demodulate the data. Further, a weight matrix for equalizing MIMO signals is calculated from the channel information of the control signal, the signals of each spatially multiplexed relay station are separated, and the data is demodulated. Further, when the relay station communicates in a line-of-sight environment like a satellite and has channel characteristics with low frequency selectivity, synchronization / channel information by the control signal can be reflected in the equalization of the data signal. At this time, the guard band between the FDMA signals (G in the figure) can be set to a value twice the maximum Doppler frequency Δfmax assumed in the system to avoid inter-carrier interference.

<Configuration of base station 10>
FIG. 2 shows a configuration example of the base station 10.
In FIG. 2, the base station 10 includes a relay station position calculation unit 11 and a relay station frequency band allocation unit 12, and allocates frequencies of downlink control signals according to the positions of each relay station. The base station 10 further includes a downlink control signal / data signal generation unit 13, an uplink control signal reception unit 14, a terminal station detection unit 15, a request relay station detection unit 16, and a relay station selection unit 17.

<Configuration of relay stations A, B, C>
FIG. 3 shows a configuration example of relay stations A, B, and C.
In FIG. 3, the relay stations A, B, and C include a signal receiving unit 21, a frequency conversion / amplification unit 22, and a signal transmitting unit 23. The relay stations A, B, and C of this wireless communication system basically have a function of receiving a signal from the base station 10 and performing only frequency conversion and signal amplification for transmitting to the terminal stations 1, 2, and 3.

<Configuration of terminal stations 1, 2 and 3>
FIG. 4 shows a configuration example of terminal stations 1, 2, and 3.
In FIG. 4, the terminal stations 1, 2 and 3 include a downlink control signal receiving unit 31, a relay station frequency error detecting unit 32, a relay station frequency error learning unit 33, a downlink control signal synchronization unit 34, a relay station detecting unit 35, and a down. Link channel estimation unit 36, channel correlation calculation unit 37, request relay station selection unit 38, uplink control signal generation unit 39, target terminal station detection unit 40, reception equalization matrix generation unit 41, reception signal equalization / demodulation unit 42. Be prepared.

<Frame format of downlink control signal and uplink control signal>
FIG. 5 shows the frame format of the downlink control signal.
In FIG. 5, the downlink control signal is composed of a known signal for synchronization / estimation, a relay station ID, a target terminal station ID, and data signal frequency band information. Here, based on the uplink control signal received from the terminal station, a relay station is selected for the terminal station, a frequency band for transmitting the data signal is allocated, and the downlink control signal and the data signal are transmitted.

FIG. 6 shows the frame format of the uplink control signal.
In FIG. 6, the uplink control signal is composed of a known synchronization signal, a terminal station ID, and a request relay station ID.

<Example>
FIG. 7 shows an example of processing procedures of the base station 10 and the terminal stations 1, 2 and 3 in the present invention. Here, it is assumed that the relay stations A, B, and C exist at positions in the service area where they can communicate with the terminal stations 1, 2, and 3, as shown in FIG.

In FIGS. 1 to 4 and 7, the relay station position calculation unit 11 of the base station 10 can receive in the service area of the wireless communication system based on, for example, the position of each relay station calculated from known orbit information. The relay stations A, B, and C are identified (S1). The relay station frequency band allocation unit 12 of the base station 10 allocates the downlink control signals A, B, and C transmitted from the relay stations A, B, and C to the same frequency band as shown in FIG. The downlink control signal / data signal generation unit 13 of the base station 10 generates downlink control signals A, B, and C unique to each relay station, and enters the service area in the same frequency band via the relay stations A, B, and C. Send (S2).

The terminal stations 1, 2 and 3 in the service area can receive the downlink control signals A, B and C of the same frequency band transmitted from the relay stations A, B and C by the downlink control signal receiving unit 31, respectively. Receives a downlink control signal (S3). Here, different frequency errors (Doppler frequencies) are generated in the downlink control signals A, B, and C.

The relay station frequency error detection unit 32 inputs the reception waveform information of the signal on which the downlink control signal of each relay station is superimposed, the transmission signal information acquired in advance, and the information other than the transmission signal, and the relay station frequency error learning unit 33. The frequency error (Doppler frequency) of the downlink control signal of each relay station is detected based on the result of machine learning in (S4). Here, the transmission signal information is, for example, the center frequency of the transmission signal, the primary modulation method of a digital signal such as QPSK or QAM, and the single carrier modulation is a secondary modulation method such as OFDM modulation. The information other than the transmission signal is, for example, the position information of the terminal station, the azimuth angle information, the speed information, the position information of the relay station, and the like. Even if the downlink control signals of each relay station are superimposed on the same frequency band, the reception pattern is limited to some extent in an environment where the relay station has a channel model such as a satellite and the communication status is simpler than that on the ground. Therefore, for example, even in blind estimation by machine learning using a hierarchical neural network composed of an input layer, a hidden layer, and an output layer, the frequency error (Doppler frequency) of the downlink control signal of each relay station can be detected.

The downlink control signal synchronization unit 34 performs frequency synchronization of the downlink control signal of the received relay station based on the detected frequency error information (S5). For example, in the case of FIG. 1, the terminal station 1 estimates the frequency error Δf _A of the downlink control signal A of the relay station A and synchronizes the frequency, and the terminal station 2 synchronizes the downlink control signals A and B of the relay stations A and B. taking frequency synchronization frequency error Delta] f _a, a Delta] f _B estimates of the terminal station 3, the relay station a, B, C of the downlink control signals a, B, frequency error Delta] f _a of C, Delta] f _B, estimated Delta] f _C And frequency synchronization.

The relay station detection unit 35 of the terminal stations 1, 2 and 3 detects the relay station based on the relay station ID of the downlink control signal that has been received and synchronized, and the downlink channel estimation unit 36 knows the downlink control signal. Using the signal, the downlink channel information between each detected relay station and terminal station is estimated (S6). The channel correlation calculation unit 37 calculates the correlation from the channel information of each relay station, and the request relay station selection unit 38 selects a relay station that has a low channel correlation and requires MIMO transmission (S7). For example, assuming that the 3 × 3 channel matrix generated by the channel information between the three antennas of the relay stations A, B, C and the terminal station 3 is H, the larger the determinant det | H |, the lower the channel correlation. Since the transmission capacity tends to be large, the presence or absence of MIMO transmission may be set based on the value of the determinant det | H'| of the matrix H'generated by estimating the channel information at the terminal station 3.

Also, it is not always necessary to select all receivable relay stations. For example, if the terminal station 2 in FIG. 1 can receive the downlink control signals A, B, and C transmitted from the relay stations A, B, and C, but the correlation between the relay stations B and C is high, the relay station It is also possible to request MIMO transmission by selecting A and B (example of FIG. 1) or a combination of relay stations A and C. Further, since the number of antennas owned by the terminal stations 1 and 2 is less than the number of relay stations, it is essential to select a relay station having a number of antennas or less of the terminal station.

The uplink control signal generation unit 39 of the terminal stations 1, 2 and 3 adds the requested relay station information to the request relay station ID of the uplink control signal and notifies the base station 10 (S8). The notification method at this time may be any method, and may be via an arbitrary relay station or another transmission means.

The uplink control signal receiving unit 14 of the base station 10 receives the uplink control signals from the terminal stations 1, 2 and 3, the terminal station detection unit 15 detects the terminal station ID, and the request relay station detection unit 16 determines the uplink control signal. The terminal station detects a request relay station requesting MIMO transmission (S9). The relay station selection unit 17 allocates a relay station and a frequency band for transmitting a data signal addressed to each terminal station 1, 2, 3 based on the request relay station collected from each terminal station 1, 2, 3 (S10).

The downlink control signal / data signal generation unit 13 of the base station 10 generates data signals addressed to the terminal stations 1, 2 and 3 to be transmitted in the frequency bands of the relay stations A, B and C selected by the relay station selection unit 17. Further, a downlink control signal indicating the correspondence between the data signal addressed to the terminal stations 1, 2 and 3 and the frequency band is generated and transmitted to the terminal stations 1, 2 and 3 via the corresponding relay stations (S11).

In the example of FIG. 1, the data signal addressed to the terminal station 1 allocates the data signal A transmitted from the relay station A to the frequency band W1. For the data signal addressed to the terminal station 2, the data signals A and B transmitted from the relay stations A and B are multiplexed in the frequency band W2 and transmitted in MIMO. For the data signal addressed to the terminal station 3, the data signals A, B, and C transmitted from the relay stations A, B, and C are multiplexed in the frequency band W3 and transmitted by MIMO.

The target terminal station detection unit 40 of the terminal stations 1, 2, and 3 detects the downlink control signal for its own station from the downlink control signals A, B, and C, and the reception equalization matrix generation unit 41 detects the downlink channel estimation unit 36. Generates a reception weight matrix using the channel information estimated by, and the reception signal equalization / demodulation unit 42 uses the reception weight matrix to perform reception equalization of a data signal addressed to its own station and demodulate it (S12).

Further, the terminal stations 1, 2, and 3 sequentially monitor the downlink control signal of the base station 10 and change the receivable request relay station as the relay station or the terminal station moves, as in step S3. Returns to step S6 and makes a request again (S13).

The terminal station in the service area knows the center frequency of the downlink control signal, but the relay station that transmits the downlink control signal receives the relay station ID of the downlink control signal shown in FIG. Grasp.

1, 2, 3 Terminal stations 10 Base stations A, B, C Relay stations 11 Relay station position calculation unit 12 Relay station frequency band allocation unit 13 Downstream control signal / data signal generation unit 14 Upstream control signal reception unit 15 Terminal station detection unit 16 Request relay station detection unit 17 Relay station selection unit 21 Signal reception unit 22 Frequency conversion / amplification unit 23 Signal transmission unit 31 Downstream control signal reception unit 32 Relay station frequency error detection unit 33 Relay station frequency error learning unit 34 Downstream control signal synchronization Part 35 Relay station detection unit 36 Downlink channel estimation unit 37 Channel correlation calculation unit 38 Request relay station selection unit 39 Uplink control signal generation unit 40 Target terminal station detection unit 41 Reception equalization matrix generation unit 42 Reception signal equalization / demodulation unit

Claims (5)

It is equipped with one base station, a plurality of moving relay stations, and a plurality of terminal stations in the service area.
The base station identifies a relay station that can receive a signal transmitted by each relay station in the service area based on the positions of the plurality of relay stations, and is different for each terminal station via the relay station. In addition to frequency-multiplexing data signals in the frequency band, it is equipped with a downlink multi-dimensional connection means that spatially multiplex-transmits data signals via a specific frequency band and multiple relay stations to a terminal station that supports spatial multiplex transmission.
In a wireless communication system that performs downlink multiple access from a base station to each terminal station via multiple relay stations.
The downlink multiple access means of the base station includes means for transmitting a downlink control signal including a relay station ID in the same frequency band from a plurality of relay stations that can be received in the service area.
The terminal station receives the downlink control signal superimposed on the same frequency band, inputs the received waveform information, the transmission signal information acquired in advance, and peripheral information, and performs machine learning based on the result of the downlink control. The frequency error of the signal is detected, the frequency synchronization of the downlink control signal is performed based on the frequency error, and the channel information between the relay station and the terminal station is estimated from the frequency-synchronized downlink control signal. A downlink multi-dimensional connection means for selecting one or more receivable relay stations based on channel information and notifying the base station is provided.
The downlink multiplex connection means of the base station allocates the specific frequency band for spatially multiplexing the data signal addressed to the terminal station via the relay station selected by the terminal station, and transfers the information to the downlink control signal. A wireless communication system including a means for spatially multiplexing a data signal addressed to the terminal station while notifying the terminal station. In the wireless communication system according to claim 1,
The downlink control signal and the data signal addressed to the terminal station are generated from the same baseband signal and synchronized with each other.
A wireless communication system characterized in that the downlink multiple access means of the terminal station includes means for separating and demodulating the spatially multiplexed data signal using channel information estimated from the downlink control signal. It is equipped with one base station, a plurality of moving relay stations, and a plurality of terminal stations in the service area.
The base station identifies a relay station that can receive a signal transmitted by each relay station in the service area based on the positions of the plurality of relay stations, and is different for each terminal station via the relay station. In addition to frequency-multiplexing data signals in the frequency band, it is equipped with a downlink multi-dimensional connection means that spatially multiplex-transmits data signals via a specific frequency band and multiple relay stations to a terminal station that supports spatial multiplex transmission.
In a wireless communication method in which a downlink multiple access is performed from a base station to each terminal station via a plurality of relay stations.
The downlink multiple access means of the base station performs a process of transmitting a downlink control signal including a relay station ID in the same frequency band from a plurality of relay stations that can be received in the service area.
The downlink multi-dimensional connection means of the terminal station receives the downlink control signal superimposed on the same frequency band, inputs the received waveform information, the transmission signal information acquired in advance, and peripheral information, and performs machine learning. The frequency error of the downlink control signal is detected based on the above, the frequency synchronization of the downlink control signal is performed based on the frequency error, and the channel between the relay station and the terminal station from the frequency-synchronized downlink control signal. A process of estimating information, selecting one or more receivable relay stations based on the channel information, and notifying the base station is performed.
The downlink multiplex connection means of the base station allocates the specific frequency band for spatially multiplexing the data signal addressed to the terminal station via the relay station selected by the terminal station, and transfers the information to the downlink control signal. A wireless communication method characterized by notifying the terminal station of the above-mentioned system and performing a process of spatially multiplexing the data signal addressed to the terminal station. In the wireless communication method according to claim 3,
The downlink control signal and the data signal addressed to the terminal station are generated from the same baseband signal and synchronized with each other.
A wireless communication method characterized in that the downlink multiple access means of the terminal station separates and demodulates the spatially multiplexed data signal using channel information estimated from the downlink control signal. It is equipped with one base station, a plurality of moving relay stations, and a plurality of terminal stations in the service area.
The base station identifies a relay station that can receive a signal transmitted by each relay station in the service area based on the positions of the plurality of relay stations, and is different for each terminal station via the relay station. In addition to frequency-multiplexing data signals in the frequency band, it is equipped with a downlink multi-dimensional connection means that spatially multiplex-transmits data signals via a specific frequency band and multiple relay stations to a terminal station that supports spatial multiplex transmission.
In a terminal station device of a wireless communication system that performs downlink multiple access from a base station to each terminal station via a plurality of relay stations.
A machine that receives downlink control signals transmitted from the base station via the plurality of relay stations superimposed on the same frequency band, and inputs the received waveform information, transmission signal information acquired in advance, and peripheral information. A frequency error detecting means for detecting the frequency error of the downlink control signal based on the learned result, and
The frequency synchronization of the downlink control signal is performed based on the frequency error, the channel information between the relay station and the terminal station is estimated from the frequency-synchronized downlink control signal, and reception is possible based on the channel information. A terminal station apparatus including a relay station selection means for selecting one or more relay stations and notifying the base station.

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