JP2011141248A - Correlated reception processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a correlated reception processing device capable of suppressing sidelobes of a desired signal and other signals, even if multiple kinds of signals are propagated in space. <P>SOLUTION: A suppression weight calculating module 2233 calculates a suppression weight matrix WB to suppress a signal SB to zero and a suppression weight matrix WC to suppress a signal SC to zero. An unwanted signal suppression module 2232 suppresses the signals SB and SC in an input signal matrix X by multiplying a signal after FFT by the suppression weight matrices WB and WC. A sidelobe-free coefficient calculating module 2234 calculates an autocorrelated sidelobe-free coefficient matrix to suppress the sidelobes of a signal SA by considering the state of the input signal matrix X multiplied by the suppression weight matrices WB and WC. A sidelobe suppression module 2236 suppresses the sidelobes of the signal SA by multiplying the signal from the unwanted signal suppression module 2232 by the sidelobe-free coefficient matrix. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a correlation reception processing device used in a receiver mounted on, for example, a MIMO device (Multiple-Input Multiple-Output).

  In the radar apparatus, a sidelobe free method has been proposed in which the range side lobe in the received signal is free (suppressed to zero) to reduce target false detection (see, for example, Non-Patent Documents 1 and 2). In the radar apparatus using the side lobe free method, the side lobe free coefficient is calculated based on the code information of the transmission signal. Then, pulse compression processing is performed on the received signal using the sidelobe-free coefficient as a correlation coefficient. As a result, the pulse is compressed in a predetermined range to generate a steep peak, and the side lobe is suppressed (or reduced) to zero in the other ranges.

  However, the sidelobe-free method can be said to be a useful method when only the signal of the own device exists in the assumed radio wave environment in a radar form such as monostatic or bistatic. On the other hand, in a radar form such as a multi-static radar and a MIMO radar which has been actively studied in recent years, a plurality of types of signals propagate in space. Usually, in such radar forms as multistatic radar and MIMO radar, transmitters transmit transmission signals that do not interfere spatially. On the receiving side, it is necessary to separate uncorrelated signals corresponding to the number of transmitters and individually process them. In such a situation, the conventional radar apparatus using the side lobe-free method can suppress the side lobes in the signal of its own apparatus, but there is a problem that it is affected by other signals.

  Further, in a receiver used in a radar device using a conventional sidelobe-free method, receivable code information is set in advance, and only a transmission signal according to the code information is received. However, in radar forms such as multi-static radar and MIMO radar, code information is set in advance for each transmitter so that transmission signals from the transmitters do not interfere spatially. Therefore, when trying to receive a signal from a non-set transmitter by a conventional receiver, the corresponding code information has to be reset manually, which is a burden on the user.

E. Fisher, A. H. Heimovich, "Spatial diversity in radar-models and detection Performance," IEEE Trans. On Signal Processing, vol. 54, no. 3, pp. 823-838 E. Fisher, A. H. Heimovich, "Performance of MIMO Radar System: Advantages of Angular Diversity," IEEE Trans. On Signal Processing, 2004

  As described above, in a radar device using a conventional sidelobe-free method, when a plurality of types of signals are propagated in space, sidelobes in a desired signal can be suppressed. There was a problem of being affected. In addition, when trying to receive signals from different transmitters, the code information must be reset manually, which is a burden on the user.

  The present invention has been made for the above circumstances, and its purpose is to suppress undesired signals and suppress side lobes of desired signals even when a plurality of types of signals are propagated in space. It is another object of the present invention to provide a correlation reception processing apparatus that can reduce the burden on the user when receiving signals from different transmitters.

  In order to achieve the above object, a correlation reception processing apparatus according to the present invention is used for a receiver in a radar apparatus, and in the radar apparatus, a plurality of transmitters encode radio signals with their respective encoding schemes to space. An FFT unit that performs FFT (Fast Fourier Transform) processing on the reflected signal in a correlation reception processing device in which the receiver receives a reflected signal in which the plurality of radio signals are reflected by a target; The reflected signal includes an FFT unit including a specific component for a specific signal among the plurality of radio signals and an unnecessary component for an unnecessary signal other than the specific signal among the plurality of radio signals, and a sign of the unnecessary signal And a suppression weight calculation unit for calculating a suppression weight for suppressing the unnecessary component in the post-FFT signal to zero based on the conversion method, and a signal after the FFT. On the other hand, the specific component in the suppression signal is multiplied based on the unnecessary signal suppression unit that generates the suppression signal that suppresses the unnecessary component by multiplying the suppression weight, and the encoding method of the specific signal and the unnecessary signal. A side lobe free coefficient calculating unit for calculating a side lobe free coefficient for suppressing the included side lobe, and a side lobe for suppressing the side lobe by multiplying the suppression signal by the side lobe free coefficient. And a suppression unit.

  In the correlation reception processing apparatus having the above configuration, the unnecessary component is suppressed to zero by the unnecessary signal suppression unit. Then, the signal from the unnecessary signal suppression unit is multiplied by a side lobe-free coefficient considering the suppression weight of the unnecessary component. As a result, it is possible to suppress unnecessary components and suppress side lobes of specific signals.

  Further, the correlation reception processing apparatus according to the present invention is used in a receiver in a radar apparatus, and in the radar apparatus, a plurality of transmitters encode radio signals with their respective encoding schemes and transmit them to space, and the reception In a correlation reception processing apparatus for receiving a reflected signal in which the plurality of radio signals are reflected by a target, the machine performs an FFT (Fast Fourier Transform) process on the reflected signal, and the reflected signal is In the case where the specific component for the specific signal among the plurality of radio signals or the FFT unit including the unnecessary component for the unnecessary signal other than the specific signal among the plurality of radio signals, and the reflected signal is the specific component A first sub-band for suppressing a side lobe included in the specific component in the signal after the FFT based on a coding scheme of the specific signal and the unnecessary signal. Idrobe free coefficient is calculated, and when the reflected signal is the unnecessary component, a second sidelobe free coefficient for suppressing the unnecessary component based on the coding method of the specific signal and the unnecessary signal A side lobe free coefficient calculation unit for calculating the signal and suppresses the side lobe by multiplying the signal after the FFT by the first side lobe free coefficient, or the second side lobe free coefficient And a side lobe suppression unit that suppresses the unnecessary component by multiplying by.

  In the correlation reception processing apparatus having the above-described configuration, when a reflected signal including a specific component is received with reference to the reflected signal and the code information of the plurality of radio signals, the correlation reception processing apparatus automatically performs processing based on the encoding method of the signal. A side lobe free coefficient of 1 is calculated and the side lobe of a specific component is suppressed. On the other hand, when a reflected signal including an unnecessary component is received, the second side lobe-free coefficient is automatically calculated based on the encoding method of the signal, and the unnecessary component is suppressed. As a result, even when the desired signal is switched to another signal, the sidelobe free coefficient is automatically calculated without setting the encoding method corresponding to the signal again, and the sidelobe of the desired signal is reduced. It will be suppressed.

  According to this invention, even when a plurality of types of signals are propagated in the space, it is possible to suppress undesired signals and suppress side lobes of the desired signals, It is possible to provide a correlation reception processing apparatus capable of reducing the burden on the user when receiving signals from different transmitters.

It is a figure which shows the structure of the radar apparatus using the receiver using the correlation reception processing apparatus which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the function structure of the receiver in the receiver of FIG. It is a block diagram which shows the function structure of the correlation reception processing apparatus of FIG. It is a figure which shows the simulation result when not driving the correlation reception processing apparatus of FIG. It is a figure which shows the simulation result at the time of driving the correlation reception processing apparatus of FIG. It is a figure which shows the parameter specification in the simulation of FIG.4 and FIG.5. It is a block diagram which shows the function structure of the correlation reception processing apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows the concept of derivation | leading-out of Acal1 of FIG. It is a figure which shows the simulation result at the time of driving the correlation reception processing apparatus of FIG. It is a figure which shows the parameter item in the simulation of FIG. It is a figure which shows the structure of the radar apparatus using the receiver using the correlation reception processing apparatus which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows the function structure of the receiver of FIG. It is a block diagram which shows the function structure of the correlation reception processing apparatus of FIG. It is a figure which shows the simulation result at the time of driving the correlation reception processing apparatus of FIG. It is a figure which shows the parameter item in the simulation of FIG.

  Hereinafter, embodiments of a correlation reception processing apparatus according to the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic diagram showing a configuration of a radar apparatus using a receiver using the correlation reception processing apparatus according to the first embodiment of the present invention.

  The radar apparatus in FIG. 1 includes transmitters 10-1 to 10-3 and a receiver 20. Transmitters 10-1 to 10-3 each encode a signal with a phase code modulation waveform set in advance. As a result, transmission signals having no correlation with each other are transmitted from the respective transmitters 10-1 to 10-3. The transmitters 10-1 to 10-3 transmit transmission signals from the transmission antennas 11-1 to 11-3 toward the space. Further, the transmitters 10-1 to 10-3 notify the receiver 20 of code information related to the respective phase code modulation waveforms.

  The three transmission signals are reflected by the target T. The receiver 20 receives the reflected signals reflected by the target T independently of each other by N (N is a natural number of 2 or more) reception antennas 21-1 to 21 -N. Receiving devices 22-1 to 22-N are connected to the receiving antennas 21-1 to 21-N, respectively. The receiving devices 22-1 to 22-N detect the target T based on the reflected signal from the connected receiving antenna. The integration unit 23 integrates the detection results of the reception devices 22-1 to 22-N and determines the presence or absence of the target T. Then, the integration unit 23 outputs the determination result to the subsequent stage. Hereinafter, the reception device 22-1 will be described as an example.

  FIG. 2 is a block diagram illustrating a functional configuration of the reception device 22-1 in the receiver 20 of FIG.

  The reception device 22-1 in FIG. 2 includes a reception processing unit 221, a distribution unit 222, and correlation reception processing devices 233-1 to 233-3. Note that the number of correlation reception processing devices 223-1 to 223-3 corresponds to the number of transmission signals from the transmitters 10-1 to 10-3.

  The reception processing unit 221 performs reception processing on the reflected signal from the reception antenna 21-1. By this reception processing, the reflected signal is converted into a signal in the intermediate frequency band and then converted into a digital signal.

  The distribution unit 222 distributes the digital signal from the reception processing unit 221 into three. The distribution unit 222 supplies the distributed digital signals to the correlation reception processing devices 223-1 to 223-3. Here, in this embodiment, the digital signal supplied to the correlation reception processing devices 223-1 to 223-3 is a signal matrix X, and the signal matrix X has an input corresponding to the transmission signal from the transmitter 10-1. It is assumed that the signal SA, the input signal SB corresponding to the transmission signal from the transmitter 10-2, and the input signal SC corresponding to the transmission signal from the transmitter 10-3 are included. Further, the correlation reception processing devices 223-1 to 223-3 include a code information matrix A from the transmitter 10-1, a code information matrix B from the transmitter 10-2, and a code from the transmitter 10-3. An information matrix C is notified.

  FIG. 3 is a block diagram illustrating a functional configuration of the correlation reception processing device 223-1 according to the first embodiment of the present invention. The correlation reception processing devices 223-1 to 223-3 have the same configuration, and each performs pulse compression on any of the input signals SA, SB, and SC. Hereinafter, the correlation reception processing device 223-1 that performs pulse compression on the input signal SA will be described.

  The correlation reception processing device 223-1 includes an FFT (Fast Fourier Transform) unit 2231, an unnecessary signal suppression unit 2232, a suppression weight calculation unit 2233, a side lobe free coefficient calculation unit 2234, an FFT unit 2235, a side lobe suppression unit 2236, and an IFFT ( Inverse Fast Fourier Transform) part 2237 is provided.

The FFT unit 2231 receives the signal matrix X from the distribution unit 222 and performs an FFT process on the signal matrix Xz added with 0 in accordance with the number of FFT points Nf. The signal matrix Xz is shown in Formula (1).

Here, N indicates the code sequence length. The FFT unit 2231 outputs the signal derived from Equation (2) to the unnecessary signal suppression unit 2232.

Here, the matrix Q represents the FFT operation matrix shown in Expression (3), and T represents the transposition of the matrix.

The suppression weight calculation unit 2233 receives the code information matrix B from the transmitter 10-2 and the code information matrix C from the transmitter 10-3. Here, in this embodiment, the code information matrix A, the code information matrix B, and the code information matrix C are defined as Equations (4) to (6).

Also, 0 is added to the code information matrices A to C according to the FFT point Nf as in the equations (7) to (9).

The suppression weight calculation unit 2233 includes a first calculation unit 22331 and a second calculation unit 22332. Based on the code information matrix B, the first calculation unit 22331 derives a suppression weight matrix WB that suppresses the input signal SB to zero by Expression (10).

The first calculation unit 22331 outputs the suppression weight matrix WB to the unnecessary signal suppression unit 2232 and the second calculation unit 22332.

The second calculation unit 22332 calculates the suppression weight matrix WC of the input signal SC based on the suppression weight matrix WB from the first calculation unit 22331 and the code information matrix C. Here, the suppression weight matrix WC of the input signal SC is derived by Expression (11) so as to suppress the state in which the signal SC is multiplied by the suppression weight matrix WB.

Second calculation unit 22332 outputs suppression weight matrix WC to unnecessary signal suppression unit 2232.

The unnecessary signal suppression unit 2232 includes a first suppression unit 22321 and a second suppression unit 22322. The first suppression unit 22321 multiplies the signal from the FFT unit 2231 by the suppression weight matrix WB from the first calculation unit 22331. Thereby, the component of the signal SB in the input signal matrix X is suppressed to zero. The first suppression unit 22321 outputs the signal shown in Expression (12) to the second suppression unit 22322.

The second suppression unit 22322 multiplies the signal from the first suppression unit 22321 by the suppression weight matrix WC from the second calculation unit 22332. Thereby, the component of the signal SC in the input signal matrix X is suppressed to zero. Second suppression unit 22322 outputs the signal shown in Expression (13) to sidelobe suppression unit 2236.

The side lobe free coefficient calculation unit 2234, based on the code information matrices A to C, autocorrelation side lobe free for suppressing the side lobe of the signal component of the signal SA included in the signal from the unnecessary signal suppression unit 2232. A coefficient matrix Hdz is calculated. Here, the output matrix ym from the IFFT unit 2237 is given by Expression (14) as a signal in which side lobes up to ± Nx points near the main lobe are suppressed.

The output matrix ym is zero-added as shown in Expression (15) in accordance with the FFT point Nf.

The side lobe-free matrix coefficient Hdz is derived by Expression (17) so as to consider the state of the input signal matrix X multiplied by the suppression weight matrices WB and WC and to minimize the S / N loss.

Here, * indicates a complex conjugate. The side lobe free coefficient calculation unit 2234 outputs the side lobe free coefficient matrix Hdz calculated by Expression (17) to the FFT unit 2235. The FFT unit 2235 converts the coefficient matrix Hdz into a frequency domain coefficient matrix by performing FFT processing on the sidelobe-free coefficient matrix Hdz. The FFT unit 2235 outputs the coefficient matrix Hdz after the FFT processing to the sidelobe suppression unit 2236.

  The side lobe suppression unit 2236 performs pulse compression processing on the signal from the unnecessary signal suppression unit 2232 using the side lobe free coefficient matrix Hdz from the FFT unit 2235 as a correlation coefficient. Thereby, the side lobe of the input signal SA included in the signal from the unnecessary signal suppression unit 2232 is suppressed. Sidelobe suppression unit 2236 outputs a signal with sidelobe suppression suppressed to IFFT unit 2237.

  The IFFT unit 2237 performs IFFT processing on the signal from the sidelobe suppression unit 2236 and converts the signal into a time domain signal. IFFT section 2237 outputs the signal subjected to IFFT processing to the subsequent stage.

  Next, simulation results of sidelobe free and pulse compression by the correlation reception processing device 223 are shown in FIGS. In this simulation, the input signal is encoded by a flank interpolation code. FIG. 6 shows parameter specifications in this simulation.

  FIG. 4 is a diagram showing autocorrelation characteristics and cross-correlation characteristics in the signal matrix X when the correlation reception processing device 223 according to the present invention is not driven. FIG. 5 is a diagram showing autocorrelation characteristics and cross-correlation characteristics in the signal matrix X when the correlation reception processing device 223 according to the present invention is driven. It can be confirmed from FIG. 5 that driving the correlation reception processing device 223 reduces the autocorrelation PSL (Peak Sidelobe Level) and reduces the cross-correlation to zero.

  As described above, in the above embodiment, the unnecessary signal suppression unit 2232 suppresses the unnecessary signals SB and SC to zero using the suppression weight matrices WB and WC. Then, the signal from the unnecessary signal suppression unit 2232 is multiplied by a sidelobe free coefficient matrix Hdz considering the suppression weight matrices WB and WC. As a result, the signals SB and SC can be suppressed and the side lobe of the signal SA can be suppressed.

  Therefore, according to the correlation reception processing apparatus according to the present invention, even when a plurality of types of signals are propagated in the space, the undesired signals are suppressed and the side lobes of the desired signals are suppressed. be able to.

  In the first embodiment, the example in which the input signal matrix X includes the signal components SA, SB, and SC has been described. However, the present invention is not limited to this. For example, the input signal matrix X may include signal components SA and SB. In this case, the unnecessary signal suppression unit 2232 includes only the first suppression unit 22321, and suppresses the signal component SB based on the suppression weight matrix WB output from the first calculation unit 22331 of the suppression weight calculation unit 2233. It becomes.

  Further, for example, the signal component SA, SB, SC, SD may be included in the input signal matrix X. In this case, the suppression weight calculation unit 2233 further includes a calculation unit that calculates the suppression weight matrix WD. Then, the unnecessary signal suppression unit 2232 suppresses the signal component SD by multiplying the input signal matrix X by the suppression weight matrix WD.

[Second Embodiment]
FIG. 7 is a block diagram showing a functional configuration of the correlation reception processing apparatus 223 according to the second embodiment of the present invention. In the present embodiment, a correlation reception processing device 223 that performs pulse compression on the input signal SA will be described. Further, in FIG. 7, the same reference numerals are given to the portions common to FIG.

  The correlation reception processing device 223 in FIG. 7 includes an FFT (Fast Fourier Transform) unit 2231, an unnecessary signal suppression unit 2238, a suppression weight calculation unit 2233, a correction coefficient calculation unit 2239, a sidelobe free coefficient calculation unit 2234, an FFT unit 2235, a side A lobe suppression unit 2236 and an IFFT (Inverse Fast Fourier Transform) unit 2237 are provided.

  The suppression weight calculation unit 2233 includes a first calculation unit 22331 and a second calculation unit 22332. The first calculation unit 22331 calculates the suppression weight matrix WB of the input signal SB based on the code information matrix B from the transmitter 10-2 by Expression (10) in the first embodiment. Then, the first calculation unit 22331 outputs the suppression weight matrix WB to the unnecessary signal suppression unit 2238, the second calculation unit 22332, and the correction coefficient calculation unit 2239.

  Based on the suppression weight matrix WB from the first calculation unit 22331 and the code information matrix C from the transmitter 10-3, the second calculation unit 22332 generates the first suppression weight matrix WC of the input signal SC. It calculates with Formula (11) in embodiment of. Here, the suppression weight matrix WC of the input signal SC is calculated so as to suppress the state in which the signal SC is multiplied by the suppression weight matrix WB. Second calculation unit 22332 outputs suppression weight matrix WC to unnecessary signal suppression unit 2238 and correction coefficient calculation unit 2239.

  The correction coefficient calculation unit 2239 includes a third calculation unit 22391 and a fourth calculation unit 22392. The third calculation unit 22391 calculates the correction coefficient matrix Acal1 from the code information matrix A from the transmitter 10-1 and the suppression weight matrix WB from the first calculation unit 2231. The correction coefficient matrix Acal1 corrects a change in the signal component of the signal SA, which is a desired signal, generated by multiplying the suppression weight matrix WB by the input signal matrix X. FIG. 8 is a conceptual diagram of derivation of the correction coefficient matrix Acal1.

Using the code information matrix A, the signal state matrix q of the signal SA before being multiplied by the suppression weight matrix WB and the signal state matrix p of the signal SA after being multiplied by the suppression weight matrix WB are as follows: Define.

As a result, the amplitude s and the phase φ of the correction coefficient matrix Acal1 are obtained by equations (20) and (21), respectively.

Here, real () indicates the real part of the element in parentheses, and imag () indicates the imaginary part of the element in parentheses. As a result, the correction coefficient matrix Acal1 is obtained by Expression (22).

The third calculation unit 22391 outputs the correction coefficient matrix Acal1 to the unnecessary signal suppression unit 2238.

The fourth calculation unit 22392 calculates the correction coefficient matrix Acal2 from the code information matrix A from the transmitter 10-1 and the suppression weight matrix WC from the second calculation unit 22332. The correction coefficient matrix Acal2 corrects a change in the signal component of the signal SA, which is a desired signal, generated by multiplying the suppression weight matrix WC by the input signal matrix X. Using the code information matrix A, the signal state matrix q ′ of the signal SA before being multiplied by the suppression weight matrix WC and the signal state matrix p ′ of the signal SA after being multiplied by the suppression weight matrix WC are expressed as follows: Define as follows.

As a result, the amplitude s ′ and the phase φ ′ of the correction coefficient matrix Acal2 are derived from equations (25) and (26), respectively.

Thereby, the correction coefficient matrix Acal2 is obtained by the equation (27).

The fourth calculation unit 22392 outputs the correction coefficient matrix Acal2 to the unnecessary signal suppression unit 2238.

  The unnecessary signal suppression unit 2238 includes a first suppression unit 22381 and a second suppression unit 22382. The first suppression unit 22381 includes a first weight coefficient multiplication unit 223811 and a first correction coefficient multiplication unit 223812. The first weight coefficient multiplication unit 223811 multiplies the signal from the FFT unit 2231 by the suppression weight matrix WB from the first calculation unit 22331. Thereby, the component of the signal SB in the input signal matrix X is suppressed to zero.

  The first correction coefficient multiplier 223812 multiplies the signal from the first weight coefficient multiplier 223811 by the correction coefficient matrix Acal1 from the third calculator 22391. As a result, the change in the signal SA after being multiplied by the suppression weight matrix WB is corrected.

The suppression coefficient matrix WB ′ in the first suppression unit 22381 is expressed by Expression (28) from the suppression weight matrix WB and the correction coefficient matrix Acal1.

  The second suppression unit 22382 includes a second weight coefficient multiplication unit 223821 and a second correction coefficient multiplication unit 223822. The second weight coefficient multiplication unit 223821 multiplies the signal from the first suppression unit 22382 by the suppression weight matrix WC from the second calculation unit 22332. Thereby, the component of the signal SC in the input signal matrix X is suppressed to zero.

  The second correction coefficient multiplication unit 223822 multiplies the signal from the second weight coefficient multiplication unit 223821 by the correction coefficient matrix Acal2 from the fourth calculation unit 22392. As a result, the change in the signal SA after being multiplied by the suppression weight matrix WC is corrected.

The suppression coefficient matrix WC ′ in the second suppression unit 22382 is expressed by Expression (29) from the suppression weight matrix WC and the correction coefficient matrix Acal2.

  The side lobe suppression unit 2236 performs pulse compression processing on the signal from the unnecessary signal suppression unit 2238 using the side lobe free coefficient matrix Hdz from the FFT unit 2235 as a correlation coefficient. Thereby, the side lobe of the input signal SA included in the signal from the unnecessary signal suppression unit 2238 is suppressed. Sidelobe suppression unit 2236 outputs a signal with sidelobe suppression suppressed to IFFT unit 2237.

The IFFT unit 2237 performs IFFT processing on the signal from the sidelobe suppression unit 2236 and converts the signal into a time domain signal. IFFT section 2237 outputs the signal subjected to IFFT processing to the subsequent stage. Thereby, the pulse compression result matrix ymz by the correlation reception processing device 223 is obtained by the equation (30).

  Next, a simulation result of sidelobe free and pulse compression by the correlation reception processing device 223 is shown in FIG. FIG. 9 is a diagram showing autocorrelation characteristics and cross-correlation characteristics in the signal matrix X when the correlation reception processing device 223 according to the present invention is driven. In this simulation, the input signal is encoded by a flank interpolation code. FIG. 10 shows parameter specifications at this time. From this result, it can be confirmed that the unwanted signals SB and SC are suppressed and the peak gain of the signal SA is also good, depending on the sidelobe free pulse compression method by the correlation reception processing device 223 according to the present embodiment.

  As described above, in the above-described embodiment, changes in the signal SA due to the suppression weight matrices WB and WC are corrected based on the correction coefficient matrices Acal1 and Acal2. As a result, it is possible to correct a change given to the desired signal SA when suppressing the unnecessary signals SB and SC. Therefore, when performing pulse compression using a sidelobe-free coefficient as a correlation coefficient, a good peak gain is obtained. Can be obtained.

  Therefore, according to the correlation reception processing apparatus according to the present invention, even when a plurality of types of signals are propagated in the space, the undesired signals are suppressed and the side lobes of the desired signals are suppressed. be able to.

  In the second embodiment, the example in which the signal components SA, SB, and SC are included in the input signal matrix X has been described. However, the present invention is not limited to this. For example, the input signal matrix X may include signal components SA and SB. In this case, the unnecessary signal suppression unit 2238 includes only the first suppression unit 22381, and the signal is determined based on the suppression weight matrix WB from the first calculation unit 22331 and the correction coefficient matrix Acal1 from the third calculation unit 22391. The component SB is suppressed.

  Further, for example, the signal component SA, SB, SC, SD may be included in the input signal matrix X. In this case, the suppression weight calculation unit 2233 further includes a calculation unit that calculates the suppression weight matrix WD, and the correction coefficient calculation unit 2239 further includes a calculation unit that calculates the correction coefficient matrix Acal3. Then, the unnecessary signal suppression unit 2238 suppresses the signal component SD by multiplying the signal from the second suppression unit 22382 by the suppression weight matrix WD and the correction coefficient matrix Acal3.

  In the first and second embodiments, the correlation reception processing apparatus that performs side lobe free and pulse compression on the signal SA has been described as an example. However, the side lobe free and pulse compression are performed on the signal SB or the signal SC. It is also possible to set to.

[Third Embodiment]
FIG. 11 is a schematic diagram showing a configuration of a radar apparatus using a receiver using a correlation reception processing apparatus according to the third embodiment of the present invention.

  The radar apparatus in FIG. 11 includes transmitters 10-1 to 10-3 and a receiver 20. Transmitters 10-1 to 10-3 each encode a transmission signal with a phase code modulation waveform set in advance. As a result, transmission signals having no correlation with each other are transmitted from the respective transmitters 10-1 to 10-3. Any one of the transmitters 10-1 to 10-3 transmits a transmission signal from the transmission antenna toward the space. Further, the transmitters 10-1 to 10-3 notify the receiver 20 of code information related to the respective phase code modulation waveforms.

  A transmission signal from any of the transmitters 10-1 to 10-3 is reflected by the target T. The receiver 20 receives the reflected signals reflected by the target T independently of each other by N (N is a natural number of 2 or more) reception antennas 21-1 to 21 -N. Receiving devices 24-1 to 24-N are connected to the receiving antennas 21-1 to 21-N, respectively. The receiving devices 24-1 to 24-N detect the target T based on the reflected signal from the connected receiving antenna. The integration unit 23 integrates the detection results of the reception devices 24-1 to 24-N and determines the presence or absence of the target T. Then, the integration unit 23 outputs the determination result to the subsequent stage. Hereinafter, the reception device 24-1 will be described as an example.

  FIG. 12 is a block diagram illustrating a functional configuration of the reception device 24-1 in FIG.

  The reception device 24-1 in FIG. 12 includes a reception processing unit 241 and a correlation reception processing device 242.

  The reception processing unit 241 performs reception processing on the reflected signal from the reception antenna 21-1. By this reception processing, the reflected signal is converted into a signal in the intermediate frequency band and then converted into a digital signal. The reception processing unit 241 supplies the digital signal to the correlation reception processing device 242. Here, in this embodiment, the digital signal supplied to the correlation reception processing device 242 is a signal matrix X, and the signal matrix X is an input signal SA corresponding to the transmission signal from the transmitter 10-1, and the transmitter 10-. 2 is an input signal SB corresponding to the transmission signal from 2 or an input signal SC corresponding to the transmission signal from the transmitter 10-3. Further, the correlation reception processing device 242 is notified of the code information matrix A from the transmitter 10-1, the code information matrix B from the transmitter 10-2, and the code information matrix C from the transmitter 10-3. The

  FIG. 13 is a block diagram showing a functional configuration of a correlation reception processing apparatus 242 according to the third embodiment of the present invention. Here, a correlation reception processing device 242 that suppresses side lobes of the signal SA and performs pulse compression of the signal SA will be described as an example.

  The correlation reception processing device 242 includes an FFT (Fast Fourier Transform) unit 2421, a side lobe free coefficient calculation unit 2422, an FFT unit 2423, a side lobe suppression unit 2424, and an IFFT (Inverse Fast Fourier Transform) unit 2425.

  The input signal matrix X is supplied to the FFT unit 2421 and the sidelobe free coefficient calculation unit 2422.

  The FFT unit 2421 receives the signal matrix X from the reception processing unit 241, and performs FFT processing on the signal matrix Xz added with 0 in accordance with the FFT point number Nf. The signal matrix Xz is represented by Expression (1) in the first embodiment. The FFT unit 2421 outputs the signal derived from Equation (2) to the sidelobe suppression unit 2424.

The side lobe free coefficient calculation unit 2422 receives the input signal matrix X from the reception processing unit 241 and the code information matrices A to C from the transmitters 10-1 to 10-3. The side lobe free coefficient calculating unit 2422 calculates a suppression weight matrix WB ′ for suppressing the signal SB and a suppression weight matrix WC ′ for suppressing the signal SC. The suppression weight matrix WB ′ is derived by Expression (31).

Here, the suppression weight matrix WB is obtained by Expression (10). Further, the matrix Acal1 is obtained by Expression (32).

Further, the suppression weight matrix WC ′ is derived by Expression (34).

Here, the suppression weight matrix WC is obtained by Expression (11). Further, the matrix Acal2 is obtained by Expression (35).

The side lobe-free coefficient matrix Hdz is derived from Expression (37) from the suppression weight matrix WB ′ derived from Expression (31) and the suppression weight matrix WC ′ derived from Expression (34).

The side lobe free coefficient calculation unit 2422 outputs the side lobe free coefficient matrix Hdz derived by Expression (37) to the FFT unit 2423. The FFT unit 2423 converts the side lobe-free coefficient matrix Hdz into a frequency domain coefficient matrix and outputs it to the side lobe suppression unit 2424.

  The side lobe suppression unit 2424 performs pulse compression processing on the signal matrix Xz from the FFT unit 2421 using the side lobe free coefficient matrix Hdz from the FFT unit 2423 as a correlation coefficient. Thereby, the signals SB and SC are suppressed, and the side lobe of the signal SA is suppressed. Sidelobe suppression unit 2424 outputs a signal with sidelobe suppression suppressed to IFFT unit 2425.

The IFFT unit 2425 converts the signal from the sidelobe suppression unit 2424 into a time domain signal, and outputs a signal represented by Expression (38).

  Next, a simulation result of sidelobe free and pulse compression by the correlation reception processing device 242 is shown in FIG. FIG. 14 is a diagram showing autocorrelation characteristics and cross-correlation characteristics in the signal matrix X when the correlation reception processing device 242 according to the present invention is driven. In this simulation, the input signal is encoded by a flank interpolation code. FIG. 15 shows parameter specifications at this time. From this result, it can be confirmed that when the signal SA is input as the input signal matrix X to the correlation reception processing device 242 according to the present embodiment, the side lobe free and pulse compression of the signal SA are performed. It can be confirmed that the peak gain of the signal SA is also good.

  As described above, in the third embodiment, the side lobe free coefficient calculation unit 2422 refers to the input signal matrix X and the code information matrices A to C, and suppresses the side lobe of the signal SA. The free coefficient is calculated. Thereby, for example, when the signal SA is received as the input signal matrix X, the side lobe free coefficient for suppressing the side lobe of the signal SA and for pulse-compressing the signal SA is automatically calculated. On the other hand, when the signals SB and SC are received as the input signal matrix X, the sidelobe free coefficient is calculated to be zero based on the WB component of Equation (31) or the WC component of Equation (34). That is, the correlation reception processing device 242 performs the suppression of the side lobes of only the signal set as the desired signal and the pulse compression of only that signal even when a plurality of types of signals are propagated in the space. Become.

  Further, when the signal SB is to be received, the side lobe free coefficient corresponding to the signal SB is automatically calculated only by setting that the signal SB is received. That is, according to the correlation reception processing apparatus according to the present embodiment, it is not necessary to newly set code information corresponding to a newly selected desired signal, and sidelobe free coefficients are automatically calculated based on the input signal matrix X. The Rukoto.

  Therefore, the correlation reception processing apparatus according to the present invention can reduce the burden on the user when trying to receive signals from different transmitters.

[Other Embodiments]
In each of the above embodiments, an example in which three transmitters 10 are used has been described. However, the number of transmitters 10 is not limited to three.

  Further, in each of the above embodiments, the example in which the receiver 20 using the correlation reception processing devices 223 and 242 is used in the MIMO radar device has been described, but the present invention is not limited to this. For example, the correlation reception processing device may be used in a receiver used in a multistatic radar device.

  Furthermore, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

10-1 to 10-3 ... Transmitters 11-1 to 11-3 ... Transmitting antenna 20 ... Receivers 21-1 to 21-N ... Receiving antennas 22-1 to 22-N, 24-1 to 24-N ... Receiving devices 221, 241 ... Receiving processing unit 222 ... Distributing units 223-1 to 223-3,242 ... Correlation receiving processing devices 2231,2421 ... FFT units 2232, 2238 ... Unnecessary signal suppressing units 22321, 23281 ... First suppressing unit 22322, 22382 ... second suppression unit 2233 ... suppression weight calculation unit 22331 ... first calculation unit 22332 ... second calculation unit 2234, 2422 ... side lobe free coefficient calculation units 2235, 2423 ... FFT units 2236, 2424 ... side Lobe suppression units 2237, 2425 ... IFFT unit 223811 ... first weight coefficient multiplication unit 223812 ... first correction coefficient multiplication unit 2 3821 ... second weight coefficient multiplication unit 223,822 ... second correction coefficient multiplication unit 2239 ... correction coefficient multiplication unit 22391 ... third calculation unit 22392 ... fourth calculator 23 ... integrating unit

Claims (5)

Used in a receiver in a radar device, in which a plurality of transmitters encode radio signals by their respective encoding methods and transmit them to space, and the receiver reflects the plurality of radio signals by a target. In the correlation reception processing device that receives the reflected signal,
An FFT unit that performs FFT (Fast Fourier Transform) processing on the reflected signal, wherein the reflected signal includes a specific component of a specific signal among the plurality of radio signals and the specific signal of the plurality of radio signals. An FFT unit including unnecessary components for unnecessary signals other than
A suppression weight calculating unit that calculates a suppression weight for suppressing the unnecessary component in the signal after the FFT to zero based on the encoding method of the unnecessary signal;
An unnecessary signal suppression unit that generates a suppression signal that suppresses the unnecessary component by multiplying the signal after the FFT by the suppression weight;
A side lobe free coefficient calculation unit that calculates a side lobe free coefficient for suppressing a side lobe included in the specific component in the suppression signal based on the encoding method of the specific signal and the unnecessary signal;
A correlation reception processing apparatus comprising: a side lobe suppression unit that suppresses the side lobe by multiplying the suppression signal by the side lobe free coefficient. The unnecessary signal includes a first unnecessary signal and a second unnecessary signal,
The unnecessary component includes a first unnecessary component and a second unnecessary component,
The suppression weight calculation unit includes a first calculation unit and a second calculation unit,
The unnecessary signal suppression unit includes a first suppression unit and a second suppression unit,
The first calculation unit calculates a first suppression weight for suppressing the first unnecessary component in the signal after the FFT to zero based on the encoding method of the first unnecessary signal,
The first suppression unit multiplies the signal after the FFT by the first suppression weight and outputs the multiplied signal to the second suppression unit,
The second calculation unit suppresses the second unnecessary component in the signal from the first suppression unit to zero based on the second unnecessary signal encoding method and the first suppression weight. Calculating a second suppression weight for
The correlation reception processing apparatus according to claim 1, wherein the second suppression unit generates the suppression signal by multiplying the signal from the first suppression unit by the second suppression weight. Correction coefficient calculation for calculating a correction coefficient for correcting a change in the state of the specific component caused by multiplying the signal after the FFT by the suppression weight based on the encoding method of the specific signal and the suppression weight Further comprising
The correlation reception processing apparatus according to claim 1, wherein the unnecessary signal suppressing unit further multiplies the correction coefficient by the signal after multiplying the suppression weight. A first correction coefficient for correcting a first state change of the specific component caused by multiplying the signal after the FFT by the first suppression weight is the encoding method of the specific signal and the first A first correction coefficient calculation unit for calculating based on the suppression weight of
A second correction coefficient for correcting a second state change of the specific component generated by multiplying the signal from the first suppression unit by the second suppression weight is an encoding method of the specific signal. And a second correction coefficient calculation unit that calculates based on the second suppression weight,
The first suppression unit further multiplies the signal after the first suppression weight is multiplied with the first correction coefficient,
The second suppression unit generates the suppression signal by further multiplying the signal after multiplying the second suppression weight by the second suppression unit. Item 3. The correlation reception processing device according to item 2. Used in a receiver in a radar device, in which a plurality of transmitters encode radio signals by their respective encoding methods and transmit them to space, and the receiver reflects the plurality of radio signals by a target. In the correlation reception processing device that receives the reflected signal,
An FFT unit that performs FFT (Fast Fourier Transform) processing on the reflected signal, wherein the reflected signal is a specific component of a specific signal among the plurality of radio signals or the specific signal of the plurality of radio signals. An FFT unit including unnecessary components for unnecessary signals other than
When the reflected signal is the specific component, a first side for suppressing a side lobe included in the specific component in the signal after the FFT based on an encoding method of the specific signal and the unnecessary signal. A lobe-free coefficient is calculated, and when the reflected signal is the unnecessary component, a second side lobe-free coefficient for suppressing the unnecessary component is determined based on the coding method of the specific signal and the unnecessary signal. A sidelobe free coefficient calculation unit for calculating,
The side lobe is suppressed by multiplying the signal after the FFT by the first side lobe free coefficient, or the unnecessary component is suppressed by multiplying the second side lobe free coefficient. A correlation reception processing device comprising: a sidelobe suppression unit.

Images