Wireless communication system, wireless communication device, wireless communication method, and signal compensation program

Abstract

A wireless communication system according to one embodiment which performs wireless communication by compensating for a signal to be processed which is analog-processed via a process by which a receiving device receives a signal which is transmitted by a transmission device by using a radio wave, wherein one or more devices among the transmission device and the receiving device estimate, by using a function model, each of a plurality of factors which decrease the accuracy of the analog processing of the signal to be processed, calculate the weight which each of the plurality of factors constitutes in the decrease in the analog processing accuracy, compensate for the signal to be processed by using each function model on the basis of the calculated weights, calculate the weight which each of the plurality of factors constitutes in the residual error which remains in the compensated signal, and subject the signal to be processed to compensation along with machine learning, on the basis of the calculated weights.

Description

[Technical Field]

[0001] The present invention relates to a wireless communication system, a wireless communication device, a wireless communication method, and a signal compensation program. [Background technology]

[0002] In wireless communications, for example, when quadrature modulation and demodulation are used, the received quadrature components I and Q may be affected by different interferences, resulting in signals with different attenuation and phase rotation (IQ imbalance).When IQ imbalance occurs, the quality of wireless communications deteriorates, so technology is needed to estimate and compensate for the phenomenon.

[0003] In addition to IQ imbalance, a technology has been proposed for wireless communication in which processed signals undergo analog processing in the process of receiving a signal transmitted by a transmitting device using radio waves, such as nonlinear distortion of an amplifier, carrier frequency offset, and phase noise (see, for example, Non-Patent Document 1).

[0004] Signals that are processed through analog processing often suffer from failures (device failures) due to analog device circuits in wireless communication devices. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] S. Fouladifard, H. Shafiee, “Frequency offset estimation in OFDM systems in presence of IQ imbalance,” ICCS, 2002, pp.214-218 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the past, when multiple device failures occurred, there was a problem that the compensation accuracy deteriorated when each individual event was estimated and compensated for. In other words, when multiple device failures occurred, residual errors could degrade the quality of wireless communication.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a wireless communication system, a wireless communication device, a wireless communication method, and a signal compensation program that can accurately compensate for a processed signal that is analog-processed in the process of receiving a signal transmitted by a transmitting device using radio waves, even if multiple device failures occur in the processed signal. [Means for solving the problem]

[0008] A wireless communication system according to one embodiment of the present invention is a wireless communication system that performs wireless communication by compensating a processed signal that is analog-processed in the process of receiving a signal transmitted by a transmitting device using radio waves, wherein at least one of the transmitting device and the receiving device has a first calculation unit that estimates a plurality of factors that reduce the accuracy of analog processing of the processed signal using a function model and calculates the weight that each of the plurality of factors accounts for in the reduction in accuracy of the analog processing, a first compensation unit that compensates the processed signal using each of the function models based on the weights calculated by the first calculation unit, a second calculation unit that calculates the weight that each of the plurality of factors accounts for in the residual error remaining in the signal compensated by the first compensation unit, and a second compensation unit that performs compensation involving machine learning on the processed signal compensated by the first compensation unit based on the weights calculated by the second calculation unit.

[0009] Furthermore, a wireless communication device according to one embodiment of the present invention is a wireless communication device that performs wireless communication by compensating a processed signal that is analog-processed in the process of transmitting and receiving using radio waves, and is characterized by having: a first calculation unit that estimates a plurality of factors that reduce the accuracy of analog processing of the processed signal using a function model, and calculates the weight that each of the plurality of factors accounts for in the reduction in accuracy of the analog processing; a first compensation unit that compensates the processed signal using each of the function models based on the weights calculated by the first calculation unit; a second calculation unit that calculates the weight that each of the plurality of factors accounts for in the residual error remaining in the signal compensated by the first compensation unit; and a second compensation unit that performs compensation involving machine learning on the processed signal compensated by the first compensation unit based on the weights calculated by the second calculation unit.

[0010] Furthermore, a wireless communication method according to one embodiment of the present invention is a wireless communication method for performing wireless communication by compensating a processed signal that is analog-processed in the process of receiving a signal transmitted by a transmitting device using radio waves, the method comprising the steps of: a first calculation step of estimating, using a function model, each of a plurality of factors that reduce the accuracy of analog processing of the processed signal, and calculating a weight that each of the plurality of factors accounts for in the reduction in accuracy of the analog processing; a first compensation step of compensating the processed signal using each of the function models based on the weights calculated in the first calculation step; a second calculation step of calculating a weight that each of the plurality of factors accounts for in the residual error remaining in the signal compensated in the first compensation step; and a second compensation step of performing compensation involving machine learning on the processed signal compensated in the first compensation step based on the weights calculated in the second calculation step. [Effects of the Invention]

[0011] According to the present invention, even if multiple device failures occur in the processed signal, which is analog-processed in the process of receiving a signal transmitted by a transmitting device using radio waves, the processed signal can be accurately compensated. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating an outline of the configuration of a wireless communication system. [Figure 2] FIG. 10 is a diagram illustrating a configuration including a compensation model of a wireless communication system that compensates for multiple device failures as a comparative example. [Figure 3] FIG. 1 is a diagram illustrating a configuration including a compensation model of a wireless communication system that compensates for multiple device failures according to an embodiment. [Figure 4] 1 is a flowchart illustrating an example of an operation of a wireless communication system according to an embodiment. [Figure 5] FIG. 2 is a diagram illustrating an example of a hardware configuration of a receiving device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] The configuration of a wireless communication system and a configuration for compensating for the quality of wireless communication will be described below with reference to the drawings. Fig. 1 is a diagram showing an outline of the configuration of a wireless communication system.

[0014] 1, the wireless communication system is configured such that, for example, radio waves transmitted by a transmitting device (transmitting station) 1 are received by a receiving device (receiving station) 2. The wireless communication system performs wireless communication by compensating processed signals that are analog-processed in the process of receiving the signals transmitted by the transmitting device 1 using radio waves at the receiving device 2.

[0015] The transmitting device 1 has a transmission digital processing unit 10, a transmission analog processing unit 12, and an antenna 14. The transmission digital processing unit 10 performs digital processing for transmitting a signal. The transmission analog processing unit 12 performs analog processing for transmitting the signal, and transmits the signal via the antenna 14.

[0016] The transmission analog processing section 12 includes, for example, a quadrature modulation circuit 30, a frequency conversion circuit 32, and a power amplification circuit .

[0017] A device impairment of IQ imbalance may occur in the quadrature modulation circuit 30. A device impairment of phase noise may occur in the frequency conversion circuit 32. A device impairment of nonlinear distortion may occur in the power amplification circuit .

[0018] The receiving device 2 has an antenna 20, a reception analog processing unit 22, and a reception digital processing unit 24. The reception analog processing unit 22 receives a signal via the antenna 20 and performs analog processing, for example, to make the signal demodulatable. The reception digital processing unit 24 performs digital processing on the signal received by the reception analog processing unit 22.

[0019] The reception analog processing unit 22 includes, for example, a frequency conversion circuit 40 and a quadrature demodulation circuit 42. A device impairment such as phase noise may occur in the frequency conversion circuit 40. A device impairment such as IQ imbalance may occur in the quadrature demodulation circuit 42.

[0020] Furthermore, a fading channel exists when the receiving device 2 receives the signal transmitted by the transmitting device 1. Furthermore, a carrier frequency offset may occur between the frequency conversion circuit 32 and the frequency conversion circuit 40.

[0021] Therefore, at least one of the transmission digital processing unit 10 and the reception digital processing unit 24 estimates each device failure for each event and performs compensation for the device failure that may occur in a complex manner.

[0022] 2 is a diagram illustrating a comparative example of a configuration including a compensation model of a wireless communication system that compensates for multiple device failures. Hereinafter, the same reference numerals are used to designate components that are substantially the same as those described above.

[0023] The wireless communication system illustrated in FIG. 2 has two function models of device impairments that may occur in the transmitting device 1 and the receiving device 2 in order to perform one-to-one wireless communication in which the receiving device 2 performs compensation.

[0024] Here, G is a functional model representation of the device impairments of the analog devices, and H100 is a transfer function of the fading channel in the transmitter 1 and the receiver 2.

[0025] Specifically, the transmission analog processing unit 12 is provided with a function model (G TX,1 )50 and function model (G TX,2 ) 52 is set for the reception analog processing unit 22. RX,1 )60 and function model (G RX,2 )62 is set.

[0026] The reception digital processing unit 24 includes a first calculation unit 70 and a first compensation unit 72 .

[0027] The first calculation unit 70 estimates a plurality of factors that reduce the accuracy of analog processing of the processed signal using function models (function model 50, function model 52, H100, function model 60, function model 62), and calculates the weight (compensation weight) that each of the plurality of factors accounts for in the reduction in accuracy of analog processing.

[0028] The first compensating section 72 compensates the processed signal that is subjected to analog processing using each of the function models (function model 50, function model 52, H100, function model 60, function model 62) based on the weights calculated by the first calculating section 70.

[0029] In this case, if multiple device failures occur, the estimation accuracy of each function of the function model may deteriorate, making it impossible to calculate appropriate compensation weights, and residual errors may cause deterioration in wireless communication quality.

[0030] 3 is a diagram illustrating a configuration including a compensation model of a wireless communication system that compensates for multiple device failures according to an embodiment. In the wireless communication system illustrated in FIG. 3, the reception digital processing unit 24 includes a second calculation unit 74 and a second compensation unit 76 in addition to the first calculation unit 70 and first compensation unit 72 described above.

[0031] The second calculation unit 74 calculates the weights (compensation weights) that each of the multiple factors accounts for with respect to the residual error remaining in the signal compensated for by the first compensation unit 72.

[0032] The second compensation unit 76 performs compensation involving machine learning on the processed signal compensated for by the first compensation unit 72, based on the weights calculated by the second calculation unit 74 and the known signal. For example, the second compensation unit 76 performs compensation involving machine learning on the processed signal by at least one of linear compensation, compensation using a neural network, and nonlinear compensation using a nonlinear activation function. Note that the nonlinear compensation algorithm executed by the second compensation unit 76 is assumed to be arbitrary.

[0033] Next, an example of operation of the wireless communication system according to an embodiment will be described with reference to a flowchart of FIG.

[0034] As shown in FIG. 4, in step 100 (S100), the wireless communication system calculates the weights of the function model.

[0035] In step 102 (S102), the wireless communication system performs compensation using a function model.

[0036] In step 104 (S104), the wireless communication system calculates weights for nonlinear compensation. For example, the wireless communication system learns nonlinear compensation weights based on the compensation result using the function model and the known signal so as to minimize the residual error.

[0037] In step 106 (S106), the wireless communication system performs nonlinear compensation for the residual error, for example, the wireless communication system performs the residual error compensation based on the compensation result using the function model and the nonlinear compensation weight.

[0038] In step 108 (S108), the wireless communication system performs digital processing such as demodulation.

[0039] In addition, the wireless communication system according to an embodiment estimates and compensates for device failures using multiple function models. Furthermore, the wireless communication system may use any number of function models, or may not use any function models.

[0040] Furthermore, the configuration of a wireless communication system according to one embodiment is not limited in its form, including the number of systems such as one-to-one communication, one-to-many communication, many-to-many communication, and multi-hop communication via relay stations (including regenerative relay / non-regenerative relay), antenna configurations such as SIMO / MIMO, and signal properties such as single-carrier / multi-carrier transmission.

[0041] Furthermore, in the wireless communication system according to an embodiment, the nonlinear compensation process may be performed by any of the wireless communication devices, such as the transmitting station, receiving station, or relay station, and the number of wireless communication devices is not limited.

[0042] In this way, the wireless communication system of one embodiment performs compensation using machine learning even for residual errors remaining in the compensated signal, so that even if a complex device failure occurs in the processed signal that is analog-processed in the process of receiving the signal transmitted by the transmitting device using radio waves, the processed signal can be accurately compensated.

[0043] In addition, each function possessed by the transmitting device 1 and the receiving device 2 may be configured in part or in whole by hardware such as a PLD (Programmable Logic Device) or an FPGA (Field Programmable Gate Array), or may be configured as a program executed by a processor such as a CPU.

[0044] For example, the receiving device 2 can be realized using a computer and a program, and the program can be recorded on a storage medium or provided via a network.

[0045] Fig. 5 is a diagram illustrating an example of a hardware configuration of a receiving device 2 according to an embodiment. As shown in Fig. 5, the receiving device 2 has an input unit 90, an output unit 91, a communication unit 92, a CPU 93, a memory 94, and an HDD 95 connected via a bus 96, and has the functions of a computer. The receiving device 2 is also configured to be able to input and output data to and from a computer-readable storage medium 97.

[0046] The input unit 90 is, for example, a keyboard and a mouse, etc. The output unit 91 is, for example, a display device such as a display.

[0047] The communication unit 92 is a communication interface that performs wireless communication.

[0048] The CPU 93 controls each component of the receiving device 2 and performs predetermined processing, etc. The memory 94 and the HDD 95 are storage devices that store data, etc.

[0049] The storage medium 97 is capable of storing programs and the like that cause the receiving device 2 to execute the functions of the receiving device 2. Note that the architecture that configures the receiving device 2 is not limited to the example shown in FIG. [Explanation of symbols]

[0050] REFERENCE SIGNS LIST 1 transmitter, 2 receiver, 10 transmission digital processing unit, 12 transmission analog processing unit, 14 antenna, 20 antenna, 22 reception analog processing unit, 24 reception digital processing unit, 30 quadrature modulation circuit, 32 frequency conversion circuit, 34 power amplifier circuit, 40 frequency conversion circuit, 42 quadrature demodulation circuit, 50, 52, 60, 62 function model, 70 first calculation unit, 72 first compensation unit, 74 second calculation unit, 76 second compensation unit, 90 input unit, 91 output unit, 92 communication unit, 93 CPU, 94 memory, 95 HDD, 96 bus, 97 storage medium, 100 H (transfer function)

Claims

1. In a wireless communication system, a signal transmitted by a transmitting device using radio waves is analog-processed in a process for being received by a receiving device, and the signal is compensated for to perform wireless communication. At least one of the transmitting device and the receiving device a first calculation unit that estimates a plurality of factors that reduce the accuracy of analog processing of the processed signal using a function model, and calculates a weight that each of the plurality of factors accounts for in the reduction of the accuracy of the analog processing; a first compensation unit that compensates the processed signal using each of the function models based on the weights calculated by the first calculation unit; a second calculation unit that calculates a weight that each of the plurality of factors occupies with respect to a residual error remaining in the signal compensated by the first compensation unit; a second compensation unit that performs compensation involving machine learning on the processed signal compensated by the first compensation unit based on the weight calculated by the second calculation unit; A wireless communication system comprising:

2. The second compensation unit Compensating the processed signal with machine learning by at least one of linear compensation, compensation by a neural network, and nonlinear compensation using a nonlinear activation function.

2. The wireless communication system according to claim 1, wherein:

3. A wireless communication device that performs wireless communication by compensating a processed signal that is analog-processed in the process of transmitting and receiving using radio waves, a first calculation unit that estimates a plurality of factors that reduce the accuracy of analog processing of the processed signal using a function model, and calculates a weight that each of the plurality of factors accounts for in the reduction of the accuracy of the analog processing; a first compensation unit that compensates the processed signal using each of the function models based on the weights calculated by the first calculation unit; a second calculation unit that calculates a weight that each of the plurality of factors occupies with respect to a residual error remaining in the signal compensated by the first compensation unit; a second compensation unit that performs compensation involving machine learning on the processed signal compensated by the first compensation unit based on the weight calculated by the second calculation unit; A wireless communication device comprising:

4. The second compensation unit Compensating the processed signal with machine learning by at least one of linear compensation, compensation by a neural network, and nonlinear compensation using a nonlinear activation function.

4. The wireless communication device according to claim 3,

5. A wireless communication method for wireless communication in which a processed signal undergoes analog processing in a process in which a signal transmitted by a transmitting device using radio waves is received by a receiving device, the method comprising: a first calculation step of estimating a plurality of factors that reduce the accuracy of analog processing of the processed signal using a function model, and calculating a weight that each of the plurality of factors accounts for in the reduction in accuracy of the analog processing; a first compensation step of compensating the processed signal using each of the function models based on the weights calculated in the first calculation step; a second calculation step of calculating a weight that each of the plurality of factors occupies with respect to the residual error remaining in the signal compensated by the first compensation step; a second compensation step of performing compensation involving machine learning on the processed signal compensated in the first compensation step based on the weight calculated in the second calculation step; A wireless communication method comprising:

6. In the second compensation step, Compensating the processed signal with machine learning by at least one of linear compensation, compensation by a neural network, and nonlinear compensation using a nonlinear activation function.

6. The wireless communication method according to claim 5,

7. A signal compensation program for causing a computer to function as each unit of the wireless communication device according to claim 3 or 4.

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