Radio signal processing device and radio signal processing method

Abstract

To provide a radio signal processing device capable of detecting a radar signal interfering with a received signal and suppressing signal interference between the received signal and the radar signal.SOLUTION: A radio signal processing device 100 includes a storage unit 120, a weight information multiplication unit 111, an FFT processing unit 112, an amplitude addition unit 113, and a threshold determination unit 114. The storage unit 120 stores weight information for canceling the frequency sweep of an interference signal that interferes with the received signal, which is information determined on the basis of the frequency sweep speed of the interference signal. The weight information multiplication unit 111 multiplies the received signal and the weight information. The FFT processing unit 112 performs fast Fourier transform processing on the multiplication result. The amplitude addition unit 113 adds the amplitude value calculated by the FFT processing unit 112 for each frequency bin processed by FFT processing unit 112, and calculates the sum of the amplitude values for the frequency bins. The threshold determination unit 114 determines whether the total value of frequency bins is greater than a predetermined threshold value.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a radio signal processing device and a radio signal processing method. [Background technology]

[0002] The frequency bands of signals used in a wireless communication system for wireless communication and a radar system for object detection or the like may overlap, causing interference between the wireless signal of the wireless communication system and the radar signal. Techniques have been proposed for eliminating the interference between the wireless signal and the radar signal. Patent Document 1 discloses a wireless communication device capable of detecting a chirp radar whose frequency changes over time. The wireless communication device disclosed in Patent Document 1 determines whether a received signal is a chirp radar signal or not based on the change in frequency over time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-53117 A Summary of the Invention [Problem to be solved by the invention]

[0004] The wireless communication device disclosed in Patent Document 1 performs wireless communication at a predetermined frequency. Therefore, when this wireless communication device detects a chirp radar signal, it surrenders the frequency of the wireless communication device to the system used by the chirp radar. That is, when the wireless communication device disclosed in Patent Document 1 detects a radar signal, it changes the frequency used in wireless communication to a frequency different from the frequency used by the detected chirp radar, and performs wireless communication at the changed frequency. Therefore, in this wireless communication device, every time a chirp radar signal is detected, it is necessary to change the frequency of the wireless communication device to a frequency that does not interfere with the frequency of the radar signal used by the chirp radar.

[0005] The present invention has been made in consideration of the problems inherent in the conventional techniques, and an object of the present invention is to provide a wireless signal processing device capable of detecting a radar signal interfering with a received signal and suppressing signal interference between the received signal and the radar signal. [Means for solving the problem]

[0006] A wireless signal processing device according to an embodiment of the present invention includes a memory unit that stores weight information, which is information determined based on a frequency sweep speed of an interfering signal that has interfered with a received signal, for canceling the frequency sweep of the interfering signal; a weight information multiplication unit that multiplies the received signal by the weight information; an FFT processing unit that performs fast Fourier transform processing on a multiplication result obtained by the weight information multiplication unit; an amplitude addition unit that adds the amplitude values ​​calculated by the FFT processing unit for each frequency bin processed by the FFT processing unit and calculates a sum of the amplitude values ​​for the frequency bins; and a threshold determination unit that determines whether the sum of the frequency bins is greater than a predetermined threshold value.

[0007] A wireless signal processing method according to another aspect of the present invention is a wireless signal processing method executed by a computer, which multiplies a received signal by weighting information, the weighting information being determined based on a frequency sweep speed of an interfering signal that has interfered with the received signal, for canceling the frequency sweep of the interfering signal, performs fast Fourier transform processing on the multiplication result, adds amplitude values ​​calculated by the fast Fourier transform processing for each frequency bin calculated by the fast Fourier transform processing, calculates a sum of the amplitude values ​​for the frequency bins, and determines whether the sum of the frequency bins is greater than a predetermined threshold value. Effect of the Invention

[0008] According to the present invention, it is possible to provide a radio signal processing device capable of detecting a radar signal interfering with a received signal and suppressing signal interference between the received signal and the radar signal. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing a configuration of a wireless communication system according to an embodiment of the present invention. [Diagram 2] 2 is a block diagram showing an example of the configuration of a receiver according to the present embodiment. FIG. [Figure 3A] 2 is a diagram showing the configuration of a preamble portion of received data applied in the wireless communication system according to the present embodiment. FIG. [Figure 3B] 4 is a diagram showing the configuration of a header portion of received data applied in the wireless communication system according to the present embodiment. FIG. [Figure 3C] 2 is a diagram showing the configuration of a payload portion of received data applied in the wireless communication system according to the present embodiment. FIG. [Figure 4] 4 is a diagram for explaining parameters of a received signal applied in the wireless communication system according to the present embodiment. FIG. [Figure 5A] 4A and 4B are diagrams for explaining the relationship between a received signal and a radar signal according to the present embodiment. [Figure 5B] FIG. 5B is an enlarged schematic diagram of a region A in FIG. 5A. [Figure 6] 1 is a block diagram showing a configuration of a wireless signal processing device according to an embodiment of the present invention; [Figure 7] 10 is a diagram for explaining the relationship between blocks of a payload section and frequency bins according to the present embodiment. FIG. [Figure 8] 10A to 10C are diagrams for explaining the results of interference signal suppression processing in the wireless signal processing device according to the present embodiment. [Figure 9] 11A and 11B are diagrams illustrating evaluation results of received signals in the wireless signal processing device according to the present embodiment. [Figure 10] 5 is a flowchart illustrating an example of processing performed by the wireless signal processing device according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the radio signal processing device 100 according to the present embodiment will be described in detail with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios. In addition, in the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0011] Fig. 1 is a diagram showing a configuration of a wireless communication system 10 according to this embodiment. In the example shown in Fig. 1, the wireless communication system 10 includes a transmitter 200 and a receiver 300. The wireless communication system 10 transmits, for example, transmission data sent from a device (not shown) as a transmission signal via the transmitter 200. In the wireless communication system 10, the receiver 300 receives the transmission signal sent from the transmitter 200 as a reception signal, and sends it to the device (not shown). In the example shown in Fig. 1, a case is shown in which a reception signal received by the receiver 300 and a radar signal interfere with each other.

[0012] The wireless communication system 10 in this embodiment uses millimeter wave wireless communication in the 60 GHz band defined by the wireless communication standard IEEE802.11ad (hereinafter referred to as the 11ad standard).

[0013] Fig. 2 is a block diagram showing a functional configuration of a receiver 300 in this embodiment. The receiver 300 includes a frame acquisition unit 310 (Frame Acquisition), an FFT 320 (Fast Fourier Transform), and a channel estimation unit 330 (Channel Estimation). The receiver 300 also includes a detection unit 340 (Detection), and an equalization interference suppression unit 350 (Equalization, Mitigation). The receiver 300 also includes an IFFT unit 360 (Inverse FFT), a demodulation unit 370 (Demodulation), and a decoder unit 380 (Decoder). The radio signal processing device 100 (see Fig. 6) according to this embodiment is configured by the functions included in the detection unit 340 and the equalization interference suppression unit 350. Details of the radio signal processing device 100 will be described later.

[0014] Receiver 300 acquires and synchronizes a frame from a received signal in frame acquisition section 310. Specifically, frame acquisition section 310 performs frame synchronization by detecting correlation in a Short Training Field (STF) of a preamble section (see FIG. 3A) in the received signal.

[0015] The FFT unit 320 performs FFT processing (Fast Fourier Transform) on the payload portion of the received signal (see FIG. 3C) to convert the received signal into the frequency domain.

[0016] The channel estimation unit 330 estimates a channel response using a channel estimation field (CEF) in the header portion (see FIG. 3B).

[0017] The detector 340 detects an interference signal from the blocks that make up the payload portion. The detection of an interference signal will be described later.

[0018] The equalization interference suppression unit 350 performs frequency equalization processing to improve the deterioration of the reception characteristics of the received signal. In this embodiment, the equalization interference suppression unit 350 also performs processing to suppress an interference signal that has interfered with the received signal.

[0019] The IFFT unit 360 performs IFFT processing (inverse fast Fourier transform) on the received signal processed by the equalization interference suppression unit 350. The demodulation unit 370 performs demodulation processing on the result of the processing by the IFFT unit 360. Furthermore, the decoder unit 380 performs decoding processing on the coded data on the result of the demodulation processing by the demodulation unit 370. In this embodiment, data transmitted and received in the wireless communication system 10 is coded by LDPC (Low-Density Parity-check Code). The decoder unit 380 decodes the LDPC-coded received data and sends it to a downstream device (not shown).

[0020] 3A to 3C are diagrams showing the configuration of received data processed by the wireless communication system 10 according to this embodiment. As described above, the received data processed by the wireless communication system 10 is configured in a data format compatible with the 11ad standard. As shown in Fig. 3A to 3C, the received data is configured in a frame format of a preamble part, a header part, and a payload part.

[0021] FIG. 4 shows parameters when the Modulation and Coding Scheme (MCS) is 6 in the 11ad standard applied to the received signal in this embodiment. As shown in FIG. 4, in this embodiment, the received signal has a center frequency of 62.64 GHz. Also, the chip time (hereinafter, T c The signal width (hereinafter referred to as the chip time) is 0.57 ns. The chip time is the time related to the smallest unit (sample) constituting the received signal. The modulation method is SC-PHY (single carrier) (π / 2-QPSK). The error correction code used is LDPC. The coding rate is 0.5, and the minimum number of code words is 23.

[0022] The preamble part is a concatenated Golay sequence Ga 128 and Gb 128 The preamble has two parts, STF and CEF. STF is 2176T c CEF is a short field with a duration of 1152T c The STF and CEF are used for frame synchronization and channel estimation, respectively.

[0023] The header section is used to transmit information about the following payload section.

[0024] The payload section is a 64-sample Golay sequence Ga 64The payload consists of a block of 512 samples, including a GI (Guard Interval) consisting of N blk (N blk That is, the payload section contains block numbers n=1 to N as shown in FIG. blk N up to blk and a GI at the end. In this embodiment, the GI section in the payload portion is used to detect an interference signal.

[0025] (Radar signal structure) The radar signal, which is a signal that is a target of the interference signal in this embodiment, is a radar signal used in a radar of the FMCW (Frequency Modulated Continuous Wave) type. The FMCW radar is used, for example, in a 60 GHz band for a motion sensor or an in-vehicle occupant detection sensor. The FMCW radar can use an ultra-wideband with a maximum bandwidth of 7 GHz, and can detect occupants with a high-precision distance resolution.

[0026] FMCW radar uses a chirp signal whose frequency increases linearly over time to capture the signal reflected from objects in its path and measures distance based on the transmit and receive frequencies.

[0027] As described above, the wireless communication system 10 in this embodiment uses a frequency band of 60 GHz. Similarly, the FMCW radar also uses a frequency band of 60 GHz. In recent vehicles such as automobiles, various wireless communications are used to enable communication with sensors inside the vehicle, communication between the vehicle and an external system, or communication between vehicles. In addition, in vehicles such as automobiles, radar is used for passenger detection sensors inside the vehicle and object detection outside the vehicle. Therefore, there are cases where a received signal of wireless communication interferes with a radar signal such as an FMCW radar signal. FIG. 5A shows an example of a case where a received signal interferes with an FMCW radar signal.

[0028] As shown in FIG. 5A, the radio signal is divided into a preamble section, a header section, and a payload section, in that order, and is 3328 T on the time axis. c , 1024T c , and (512 × N blk +64)T c 1 shows a received signal having a frequency band of 1.76 GHz.

[0029] In the example shown in FIG. 5A, the frequency of the FMCW radar signal increases linearly over time. The speed at which the frequency of the FMCW radar signal increases over time is called the frequency sweep speed v f In this embodiment, the frequency sweep rate v f In this embodiment, the frequency sweep rate v f is assumed to be acquired in advance based on the specifications of the FMCW radar signal to be used and stored in the memory unit of the receiver 300 by a user or the like. However, this frequency sweep rate v f The acquisition and storage of the sweep speed are not limited to the embodiment, and for example, a configuration may be used in which an FMCW radar signal is separately received and the sweep speed is acquired from the received radar signal.

[0030] 5B is a schematic diagram showing an enlarged view of the area A in FIG. 5A. FIG. 5B shows the frequency of the FMCW radar signal that is frequency swept in one payload block. As described above, in this embodiment, the frequency sweep speed v f The time for one payload block is T c × 512 = 0.57 ns × 512 = 0.29 μs. Therefore, the frequency swept of the FMCW radar signal in one payload block is 11.66 × 0.29 = 3.38 MHz.

[0031] (Functions of the wireless signal processing device 100) Next, the radio signal processing device 100 will be described in detail. Fig. 6 is a block diagram showing a functional configuration of the radio signal processing device 100 according to this embodiment. The radio signal processing device 100 includes a control unit 110 and a storage unit 120. In this embodiment, the control unit 110 and the storage unit 120 of the radio signal processing device 100 are configured as part of the functions of, for example, a control unit (not shown) of the receiver 300 and a storage unit (not shown) of the receiver 300 that constitute the receiver 300.

[0032] The control unit of the receiver 300 may be configured as, for example, a general-purpose microcomputer. In this case, a computer program for causing the microcomputer to function as the receiver 300 may be installed in the microcomputer. By executing the computer program, the microcomputer functions as a plurality of information processing circuits included in the receiver 300. The control unit of the receiver 300 may realize the plurality of information processing circuits included in the receiver 300 by software, or it is also possible to prepare dedicated hardware to configure the information processing circuits. The plurality of information processing circuits may also be configured by individual hardware.

[0033] 6, the control unit 110 of the radio signal processing device 100 configured as a part of the control unit of the receiver 300 includes, as functions, a weighting information multiplication unit 111, an FFT processing unit 112, an amplitude addition unit 113, a threshold determination unit 114, and an interference signal suppression unit 115. The weighting information multiplication unit 111, the FFT processing unit 112, the amplitude addition unit 113, the threshold determination unit 114, and the interference signal suppression unit 115 will be described in detail later.

[0034] The storage unit 120 may be a read only memory (ROM), a random access memory (RAM), a hard disk, etc. The storage unit 120 may also store various data such as input data, output data, and intermediate data for the wireless signal processing device 100 to execute processing.

[0035] 6, the storage unit 120 includes a weight information DB 121 and a calculation result DB 122. The storage unit 120 for storing these data may be one or more. For example, a single storage unit 120 may be configured to store the data in separate areas. Alternatively, the data may be distributed and stored in a plurality of storage devices installed in physically separate locations.

[0036] The weight information DB 121 stores the frequency sweep speed v of the interference signal (radar signal) that is mixed with the received signal. f The weight information for canceling the frequency sweep of the interference signal is stored.

[0037] The weighting information multiplication unit 111 multiplies the received signal by weighting information stored in the weighting information DB 121. In this embodiment, the weighting information is a complex amplitude that cancels the frequency sweep in the FMCW radar signal, and is represented by c in the following equation (1): n,k where n is the number of blocks. f is the frequency sweep rate of the radar signal. k is the frequency bin (FFT bin) number. T c is the chip time.

number

[0038] Also, the received signal is n,k In the case where the weight information multiplication unit 111 multiplies the weight information by c n,k ·r n,k (The "·" indicates multiplication.)

[0039] The FFT processing unit 112 performs fast Fourier transform processing on the multiplication results obtained by the weighting information multiplication unit 111. Specifically, the FFT processing unit 112 converts the signal multiplied by the weighting information by the weighting information multiplication unit 111 into a frequency domain signal for each block. The result of the fast Fourier transform when the block number is n is shown in equation (2). Here, the number of FFT points in the FFT processing unit 112 is 512. The vector Yn denotes a set indicating the result of the fast Fourier transform when the block number is n.

number

[0040] The amplitude addition unit 113 adds the amplitude values ​​calculated by the FFT processing unit 112 for each frequency bin processed by the FFT processing unit 112, and calculates the sum of the amplitude values ​​for the frequency bins. Specifically, the process shown in the following equation (3) is executed. Here, N blk is the number of blocks contained in the payload portion.

number

[0041] The threshold determination unit 114 determines whether or not the sum value of the frequency bins calculated by the amplitude addition unit 113 is greater than a predetermined threshold value. Specifically, the threshold determination unit 114 determines the frequency bin (interfered frequency bin) that is to be the target of suppressing an interference signal based on the following formula (4). In this embodiment, the threshold used by the threshold determination unit 114 can be set in advance in the receiver 300, and is stored in the storage unit 120, for example.

[0042] Furthermore, the threshold used in the threshold determination unit 114 of this embodiment is a value obtained by multiplying the average value of the sum of all frequency bins to be detected by two. That is, the threshold determination unit 114 determines the frequency bin with the maximum amplitude among frequency bins with amplitudes greater than twice the average value of the sum of amplitude values ​​in all frequency bins.

number

[0043] The interference signal suppression unit 115 performs a process of suppressing an interference signal in a received signal based on the result of the determination made by the threshold determination unit 114. Specifically, the interference signal suppression unit 115 performs frequency domain equalization, and performs a process of suppressing an interference signal by zero padding, which sets the amplitude value corresponding to the interfered frequency bin to zero, in the received signal transformed into the frequency domain by FFT.

[0044] Fig. 7 is a diagram for explaining the relationship between an interference signal whose frequency sweep has been cancelled and a received signal in the wireless signal processing device 100 of this embodiment. The horizontal axis of Fig. 7 indicates time, and the vertical axis indicates frequency bins (frequency). As shown by signal L1 in Fig. 7, the frequency value of a signal whose frequency sweep has been cancelled does not change over time. Therefore, signal L1 is included in a specific frequency bin. Therefore, when the amplitude adding unit 113 described above processes the sum of the amplitude values, there is a tendency for signal L1 to be included in a specific frequency bin.

[0045] 8 is a diagram showing the results of the amplitude for frequency bins when the interference signal suppression in this embodiment is not performed and when the interference signal suppression is performed. As shown in FIG. 8, it is shown that the amplitude of the frequency bin including the interference signal is high around the frequency bin 470.

[0046] The threshold value determining unit 114 in this embodiment can determine the frequency of the frequency bin with the large amplitude value as shown in FIG. 8 as the interfered frequency bin.

[0047] Further, the interference signal suppression unit 115 suppresses the interference signal by zero padding, which sets a specific frequency bin determined to include an interference signal to zero based on the result determined by the threshold determination unit 114. After performing zero padding on the first block, the interference signal suppression unit 115 specifies a frequency bin to be subjected to suppression on the subsequent blocks based on the frequency sweep speed of the interference signal, and performs suppression on all blocks from the first block onwards. As the suppression process, in addition to the interfered frequency bin, zero padding may be performed on its adjacent frequency bin or adjacent multiple frequency bins. For example, in the example shown in FIG. 8, it is shown that the frequency bin determined to include an interference signal is zero padded around 470 (including the four adjacent frequency bins above and below).

[0048] FIG. 9 shows the difference in BER (Bit Error Rate) depending on whether or not interference signal suppression processing is performed in this embodiment. In the example shown in FIG. 9, the horizontal axis indicates SNR (Signal to Noise Ratio), and the vertical axis indicates BER. Furthermore, FIG. 9 shows the evaluation results for each SIR (Signal to Interference Ratio) depending on whether or not interference suppression is performed. As shown in FIG. 9, as a result of performing interference signal suppression processing, even when the SIR is 0 dB, the BER is 10 or higher when the SNR is 2 dB or higher. -2 Also, when the SNR is 3 dB or more and the BER is 10 -4 It has been shown that improvements can be achieved up to

[0049] (Outline of processing flow of wireless signal processing device 100) Next, the flow of processing in the radio signal processing device 100 will be shown using the flowchart shown in Fig. 10. A series of operations of the radio signal processing device 100 shown in the flowchart in Fig. 10 starts when the radio signal processing device 100 is started, and ends when the operation is completed. The processing in the flowchart shown in Fig. 10 also ends when the power is turned off or an interrupt is issued to end the processing. In the following explanation of the flowchart, the same contents as those described in the above explanation of the radio signal processing device 100 will be omitted or simplified.

[0050] In step S1001, control unit 110 sets block number n to an initial value of 1. After that, the process proceeds to step S1002.

[0051] In step S1002, the weight information multiplication unit 111 multiplies the received signal by the weight information stored in the weight information DB 121. In this embodiment, the weight information is information determined based on the frequency sweep speed of an interference signal that has interfered with the received signal, and is information for canceling the frequency sweep of the interference signal.

[0052] In step S1003, the FFT processing unit 112 performs FFT processing. Specifically, the FFT processing unit 112 performs fast Fourier transform processing on the multiplication result obtained by the weight information multiplication unit 111.

[0053] In step S1004, the FFT processing unit 112 performs a fast Fourier transform process on the multiplication result obtained by the weighting information multiplication unit 111. Specifically, the FFT processing unit 112 converts the signal multiplied by the weighting information by the weighting information multiplication unit 111 into a frequency domain signal for each block.

[0054] In step S1005, the control unit 110 determines whether the block number n is N blk Here, N blk In step S1005, the control unit 110 determines whether the block number n is N blkIf it is determined that the block number n is N (step S1005: YES), the process proceeds to step S1006. blk If it is determined that this is not the case (step S1005: NO), the process proceeds to step S1009.

[0055] In step S1006, the amplitude adding unit 113 adds the amplitude values ​​calculated by the FFT processing unit 112 for each frequency bin processed by the FFT processing unit 112, and calculates the sum of the amplitude values ​​for the frequency bins.

[0056] In step S1007, the threshold determination unit 114 determines whether the sum of the frequency bins is greater than a predetermined threshold value. Specifically, the threshold determination unit 114 determines the frequency bins (interfered frequency bins) that are targets for suppressing interference signals based on the above-mentioned formula (4).

[0057] In step S1008, the interference signal suppression unit 115 performs a process of suppressing an interference signal in the received signal based on the result determined by the threshold determination unit 114. Specifically, the interference signal suppression unit 115 performs frequency domain equalization, and performs a process of suppressing the interference signal by a zero padding process that sets the interfered frequency bin to zero. Then, the process ends.

[0058] In step S1009, control unit 110 adds 1 to the value of block number n. Thereafter, the process returns to step S1002, and the process from step S1002 is repeated.

[0059] As described above, the radio signal processing device 100 includes a storage unit 120, a weight information multiplication unit 111, an FFT processing unit 112, an amplitude addition unit 113, and a threshold determination unit 114. The storage unit 120 stores weight information, which is determined based on the frequency sweep speed of an interference signal that has interfered with a received signal, for canceling the frequency sweep of the interference signal. The weight information multiplication unit 111 multiplies the received signal by the weight information. The FFT processing unit 112 performs fast Fourier transform processing on the multiplication result obtained by the weight information multiplication unit 111. The amplitude addition unit 113 adds the amplitude value calculated by the FFT processing unit 112 for each frequency bin processed by the FFT processing unit 112, and calculates the sum of the amplitude values ​​for the frequency bins. The threshold determination unit 114 determines whether or not the sum of the frequency bins is greater than a predetermined threshold value.

[0060] This radio signal processing device 100 makes it possible to detect a radar signal that has interfered with a received signal and to suppress signal interference between the received signal and the radar signal.

[0061] Moreover, the radio signal processing device 100 according to this embodiment further includes an interference signal suppression unit 115 that performs processing to suppress an interference signal that interferes with the received signal, based on the result of the determination made by the threshold determination unit 114. By using this interference signal suppression unit 115, the radio signal processing device 100 suppresses the influence of the detected interference signal, and the received signal can be used in the receiver 300 without changing its content.

[0062] For example, when a radar signal interfering with a received signal is detected and the frequency of the received signal is changed to a frequency different from the frequency of the radar signal, the received signal that should be processed cannot be processed due to the change in frequency of the received signal. In other words, a delay occurs due to receiving the signal again after the frequency change. On the other hand, the wireless signal processing device 100 in this embodiment suppresses the influence of the interference signal, so that it is not necessary to change the frequency of the received signal, and it is therefore possible to prevent the occurrence of a delay associated with the frequency change.

[0063] In addition, when detecting a radar signal interfering with a received signal and changing the frequency of the received signal to a frequency different from the frequency of the radar signal, extra processing is required to change the frequency of the received signal. For example, in a system using multiple radar signals, there are frequencies corresponding to multiple radar signals, and when a radar signal interfering with a received signal is detected, it is assumed that the changed frequency of the received signal coincides with the frequency of another radar signal. In addition, in a system using multiple radar signals, there are frequencies corresponding to multiple radar signals, and when a radar signal interfering with a received signal is detected, processing (effort) is required to find a frequency that does not interfere with the frequency of the other radar signal. In contrast, the wireless signal processing device 100 in this embodiment suppresses the influence of an interference signal, so there is no need to change the frequency of the received signal, and it is therefore possible to prevent the occurrence of the effort involved in changing the frequency.

[0064] In the above-described embodiment, the threshold used by the threshold determination unit 114 may be a value obtained by multiplying the average value of the sum of all frequency bins to be detected by two. By the threshold determination unit 114 using this threshold value to perform threshold determination, it becomes possible to more accurately detect an interference signal that has interfered with the received signal.

[0065] In the above-described embodiment, the interference signal may be an FMCW (Frequency Modulated Continuous Wave) radar signal. By applying the wireless signal processing device 100 according to the present embodiment to a wireless communication system in which interference of an FMCW radar signal is expected, it becomes possible to detect the interference signal more accurately due to the characteristic of the FMCW radar signal that the frequency increases linearly with time. For example, in an environment in which an FMCW radar signal is used for a wireless communication system in a vehicle and a radar device for passenger detection, etc., the effect of suppressing the interference signal can be expected.

[0066] (Other embodiments) Although the embodiments have been described in detail with reference to the drawings, the present embodiments are not limited to the contents described in the above embodiments. The components described above include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the configurations described above can be appropriately combined. Various omissions, substitutions, or modifications of the configurations can be made without departing from the spirit of the embodiments.

[0067] In the above embodiment, the interference signal to be detected and suppressed is an FMCW radar signal, but the embodiment is not limited to this configuration. For example, the present invention can be applied to cases where a stepped CW (Continuous Wave) signal or a narrowband signal interferes. In the case of a narrowband signal, more effective results can be expected when the frequency bins are occupied up to about 5% of the number of FFT points in the FFT processing unit 112.

[0068] In the above embodiment, the received signal is applied with data defined in the 11ad standard, but the embodiment is not limited to this configuration. For example, the wireless signal processing device 100 can be applied to block transmission in which a frame size is fixed and a CP (Cyclic Prefix) and a GI (Guard Interval) are added and transmitted.

[0069] In the above embodiment, the interference signal suppression unit 115 performs frequency domain equalization and suppresses interference signals by zero padding to set the interfered frequency bin to zero. The interference signal suppression unit 115 may further perform signal interpolation in the frequency domain after the zero padding. This configuration of performing signal interpolation after the zero padding enables the wireless signal processing device 100 to suppress only the effect of interference on the received signal. As a method of signal interpolation, for example, a method of interpolating the received signal lost due to suppression by referring to the received signal of the frequency bin surrounding the interfered frequency bin or the past received signal or received data stored in the storage unit 120 in advance can be applied.

[0070] Furthermore, a computer program (wireless signal processing program) that causes a computer to execute the processing (wireless signal processing method) in the above-mentioned wireless signal processing device 100, and a computer-readable recording medium on which the program is recorded, are included in the scope of this embodiment. Here, any type of computer-readable recording medium may be used. Furthermore, the computer program is not limited to one recorded on the recording medium, and may be one transmitted via a telecommunications line, a wireless or wired communication line, a network such as the Internet, or the like.

[0071] The features of the radio signal processing device 100 and the radio signal processing method are described below.

[0072] The radio signal processing device 100 according to the first aspect includes a storage unit 120 that stores weight information, which is information determined based on a frequency sweep speed of an interference signal interfering with a received signal, for canceling the frequency sweep of the interference signal. The radio signal processing device 100 also includes a weight information multiplication unit 111 that multiplies the received signal by the weight information. The radio signal processing device 100 also includes an FFT processing unit 112 that performs fast Fourier transform processing on a multiplication result obtained by the weight information multiplication unit 111. The radio signal processing device 100 also includes an amplitude addition unit 113 that adds the amplitude value calculated by the FFT processing unit 112 for each frequency bin processed by the FFT processing unit 112 to calculate a sum of the amplitude values ​​for the frequency bins. The radio signal processing device 100 also includes a threshold determination unit 114 that determines whether or not the sum of the frequency bins is greater than a predetermined threshold value.

[0073] According to the above configuration, the radio signal processing device 100 can detect a radar signal interfering with a received signal, and suppress signal interference between the received signal and the radar signal.

[0074] The radio signal processing device 100 according to the second aspect may further include an interference signal suppression unit 115 that performs a process of suppressing an interference signal that interferes with the received signal, based on the result of the determination made by the threshold determination unit 114.

[0075] According to the above configuration, the interference signal suppressor 115 enables the radio signal processing device 100 to suppress the influence of the detected interference signal, and the received signal can be used by the receiver 300 without changing its content.

[0076] The threshold value used in the radio signal processing device 100 according to the third embodiment may be a value obtained by multiplying the average value of the sum of all frequency bins to be detected by two.

[0077] According to the above configuration, the threshold decision unit 114 performs threshold decision using this threshold, and the wireless signal processing device 100 can more accurately detect an interference signal that has interfered with the received signal.

[0078] The interference signal to be processed by the radio signal processing device 100 according to the fourth embodiment may be an FMCW (Frequency Modulated Continuous Wave) radar signal.

[0079] According to the above configuration, by applying the wireless signal processing device 100 according to the present embodiment to a wireless communication system where FMCW radar signals are interfered with, it becomes possible to detect the interfering signal more accurately due to the characteristic of FMCW that the frequency increases linearly with time. For example, in an environment where FMCW radar signals are used for a wireless communication system in a vehicle and a radar device for passenger detection, etc., the effect of suppressing the interfering signal can be expected.

[0080] A radio signal processing method according to a fifth aspect is a radio signal processing method executed by a computer. The radio signal processing method multiplies a received signal by weight information, which is information determined based on a frequency sweep speed of an interference signal interfering with the received signal and is used to cancel the frequency sweep of the interference signal. The radio signal processing method also performs a fast Fourier transform process on a result of the multiplication. The radio signal processing method also adds amplitude values ​​calculated by the fast Fourier transform process for each frequency bin calculated by the fast Fourier transform process, and calculates a sum of the amplitude values ​​for the frequency bins. The radio signal processing method also determines whether the sum of the frequency bins is greater than a predetermined threshold value.

[0081] According to the above configuration, the radio signal processing method makes it possible to detect a radar signal interfering with a received signal and to suppress signal interference between the received signal and the radar signal. [Explanation of symbols]

[0082] 100 Wireless signal processing device 111 Weight information multiplication unit 112 FFT processing section 113 Amplitude Adder 114 Threshold judgment unit 115 Interference signal suppression section 120 Storage section

Claims

1. A storage unit that stores weight information for canceling the frequency sweep of an interference signal, the weight information being determined based on a frequency sweep speed of an interference signal that interferes with a received signal; a weighting information multiplication unit that multiplies the received signal by the weighting information; an FFT processing unit that performs a fast Fourier transform process on a multiplication result obtained by the weight information multiplication unit; an amplitude adding unit that adds the amplitude values ​​calculated by the FFT processing unit for each frequency bin processed by the FFT processing unit and calculates a sum of the amplitude values ​​for the frequency bin; a threshold determination unit that determines whether the sum value of the frequency bins is greater than a predetermined threshold value; A wireless signal processing device comprising:

2. An interference signal suppression unit that performs a suppression process of the interference signal interfering with the received signal based on a result determined by the threshold determination unit. The radio signal processing device according to claim 1 .

3. The threshold value is a value obtained by multiplying the average value of the sum of all the frequency bins to be detected by two.

3. The radio signal processing device according to claim 1 or 2.

4. The interference signal is a Frequency Modulated Continuous Wave (FMCW) radar signal. The radio signal processing device according to claim 1 .

5. 1. A computer-implemented method for wireless signal processing, comprising: multiplying the received signal by weight information for canceling the frequency sweep of the interference signal, the weight information being determined based on a frequency sweep speed of the interference signal interfering with the received signal; A fast Fourier transform is performed on the multiplied result. adding the amplitude values ​​calculated by the fast Fourier transform processing for each frequency bin calculated by the fast Fourier transform processing to calculate a sum of the amplitude values ​​for the frequency bins; determining whether the sum value of the frequency bins is greater than a predetermined threshold value; A method for processing radio signals.

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