Radar device, object detection method and program

Abstract

To provide a radar device that can be angular-separated even when opening is small and can be distance-separated even in a narrow-bandwidth, a method for detecting an object target, and a program.SOLUTION: The present invention includes: a signal sending-receiving unit 11 for receiving a signal reflected by at least one target by a plurality of antennas located in realistically or virtually different positions; and a separation processing unit 13A-5 for separating the angle of the at least one target on the basis of the result of operation conducted by using reception signals received by the antennas and the coefficient of an autoregressive mode.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a radar device, an object detection method, and a program. [Background technology]

[0002] A radar device is used, for example, in a vehicle to detect the relative position of a target as seen from the vehicle. In such an application in the vehicle (for example, detecting an area where the vehicle can be parked), it is preferable to detect the positions of multiple targets in a state where they are separated from one another, but there are cases where a signal corresponding to one target drowns out signals corresponding to other targets.

[0003] Patent Document 1 describes a radar device that changes the frequency of a pulse radar and detects a target signal that is buried in a side lobe in the process of processing a plurality of measurement results related to the target in a composite band. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-315738 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the radar device described in Patent Document 1 does not separate targets when they are close to each other in the distance direction. Whether multiple targets can be distinguished as individual targets when they are close to each other in the distance direction depends on the distance resolution of the radar device, so distance resolution can be improved by expanding the bandwidth of the transmitted signal. However, when the bandwidth is widened, the radar device needs to be configured to support the wideband, and transmitting a wide-bandwidth signal may affect other radar devices.

[0006] An object of the present invention is to provide a radar device, an object detection method, and a program that can achieve angular separation even with a small aperture and distance separation even with a narrow band. [Means for solving the problem]

[0007] The means for solving the problems of the present invention are as follows. (1) A radar device comprising: a signal transmitting / receiving unit that receives signals reflected by one or more targets using a plurality of antennas that are actually or virtually located at different positions; and a separation processing unit that separates the angles of the targets based on the results of a calculation performed using the signals received by the plurality of antennas and the coefficients of an autoregressive model. (2) The radar device according to (1), further comprising: an acquisition unit that acquires first amplitude information for each of the received signals with respect to a distance from the plurality of antennas; an extraction unit that extracts, from the first amplitude information for each of the received signals acquired by the acquisition unit, the first amplitude information corresponding to a predetermined distance from the plurality of antennas as information of an antenna channel signal for each of the antennas; a calculation unit that calculates coefficients of the autoregressive model based on the information of the antenna channel signal; and an expansion unit that estimates and expands the information of the antenna channel signal in an antenna direction based on the information of the antenna channel signal and the coefficients of the autoregressive model, wherein the separation processing unit processes the information of the expanded antenna channel signal expanded by the expansion unit to separate the first amplitude information for each target. (3) The radar device of (1), comprising: an acquisition unit that acquires first amplitude information with respect to a distance from the plurality of antennas for each of the received signals; an extraction unit that extracts, from the first amplitude information for each of the received signals acquired by the acquisition unit, the first amplitude information corresponding to a predetermined distance from the plurality of antennas as information of an antenna channel signal for each of the antennas; a first calculation unit that calculates coefficients of the autoregressive model based on the first amplitude information corresponding to the predetermined distance from the antenna; a second calculation unit that calculates phase information and second amplitude information corresponding to target signals reflected from the one or more targets based on the coefficients of the autoregressive model; and a position estimation unit that reconstructs target signals using the separation processing unit based on the phase information and the second amplitude information of the target signals calculated by the second calculation unit, and estimates positions of the one or more targets based on the reconstructed target signals. (4) An object detection method comprising: a signal transmission / reception step of receiving signals reflected by one or more targets using a plurality of antennas arranged at different positions, either actually or virtually; and a separation processing step of separating the angles of the targets based on the results of a calculation performed using each of the received signals received by the plurality of antennas and the coefficients of an autoregressive model. (5) A program for causing a computer to execute a signal transmission / reception process for receiving signals reflected by one or more targets using multiple antennas located at different positions, either actually or virtually, and a separation processing process for separating the angles of the targets based on the results of calculations performed using the respective received signals received by the multiple antennas and the coefficients of an autoregressive model. [Effects of the Invention]

[0008] According to the present disclosure, angular separation is possible even with a small aperture, and distance separation is possible even with a narrow band. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing the configuration of a radar device according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of an antenna of a signal transmitting / receiving unit. [Figure 3] FIG. 3 is a diagram illustrating the antenna direction. [Figure 4] FIG. 4 is a flowchart showing the procedure of signal processing by the radar device according to the first embodiment. [Figure 5] FIG. 5 is a flowchart showing the procedure of signal processing by the radar device according to the first embodiment. [Figure 6] FIG. 6 is a diagram illustrating the configuration of the signal processing unit related to the flowcharts shown in FIGS. [Figure 7] FIG. 7 is a diagram showing the results (range angle map) detected by the peak detection unit. [Figure 8] FIG. 8 is a block diagram showing the configuration of a radar device according to the second embodiment. [Figure 9] FIG. 9 is a flowchart showing the procedure of signal processing by the radar device according to the second embodiment. [Figure 10] FIG. 10 is a flowchart showing the procedure of signal processing by the radar device according to the second embodiment. [Figure 11] FIG. 11 is a diagram illustrating the configuration of the signal processing unit related to the flowcharts shown in FIGS. [Figure 12] FIG. 12 is a diagram showing the results of the distance evaluation process when the number of targets is assumed to be three. [Figure 13] FIG. 13 is a diagram showing the results of the angle evaluation process when the number of targets is assumed to be three. [Figure 14] FIG. 14 is a flowchart showing the procedure of the object detection method. [Figure 15] FIG. 15 is a diagram illustrating the configuration of a computer. [Figure 16] FIG. 16 is a diagram showing another configuration of a computer. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, an embodiment of the present invention will be described.

[0011] (Regarding the first embodiment) 1 is a block diagram showing the configuration of a radar device 100 according to the first embodiment. The radar device 100 according to the first embodiment includes a signal transmitting / receiving unit 11 that receives a reflected wave from a target when a transmitted signal is reflected by the target, a signal processing unit 13A that processes the signal received by the signal transmitting / receiving unit 11, and a data processing unit 14. The radar device 100 is a device that radiates radio waves and receives the reflected wave from the target, and detects the presence of the target, as well as its distance, relative speed, angle, etc., from the propagation time.

[0012] The signal transmitting / receiving unit 11 receives signals reflected by one or more targets using a plurality of antennas arranged at different positions, either actually (physically) or virtually.

[0013] The configuration and operation of the signal transmitting / receiving unit 11 will now be described. The signal transmitting / receiving unit 11 is configured with one or more transmitting antennas and one or more receiving antennas. There are several possible configurations of transmitting antennas and receiving antennas. In this embodiment, a configuration with multiple transmitting antennas and multiple receiving antennas will be described as an example. However, the present invention is not limited to this configuration, and the signal transmitting / receiving unit 11 may be configured with one transmitting antenna and multiple receiving antennas. The signal transmitting / receiving unit 11 employs the FCM (Fast-Chirp Modulation) method, but may also employ the FMCW (Frequency Modulated Continuous Wave) method or a pulse method. The FCM method continuously transmits a transmitting frequency while sweeping it at high speed in units of several to several tens of microseconds, and measures the distance, speed, and angle by analyzing the frequency difference with the reflected wave. The FMCW method employs frequency modulation (FM) as the modulation method, and measures the distance, speed, and angle from the frequency difference (beat frequency) between the transmitted wave and the reflected wave. The pulse method involves intermittently emitting radio waves, measuring the distance by measuring the round-trip time of the pulse, and measuring the speed and angle by analyzing the frequency.

[0014] Furthermore, the frequency bands used by the radar device 100 are, for example, the quasi-millimeter wave band (24.05 to 24.25 GHz, 24 GHz band) and the millimeter wave band (76 to 81 GHz), but are not limited to these frequency bands.

[0015] The signal processing unit 13A includes a separation processing unit 13A-5 and a position estimation unit 13A-6, and supplies the results of the signal processing to the data processing unit .

[0016] The separation processing unit 13A-5 separates the angles of the targets based on the results of a calculation performed using the respective received signals received by the multiple antennas (signal transmitting / receiving unit 11) and the coefficients of the autoregressive model. That is, the separation processing unit 13A-5 separates the multiple received signals into target signals reflected from each target based on the results of a calculation performed using the multiple received signals and the coefficients of the autoregressive model.

[0017] The position estimation unit 13A-6 estimates the position of each target based on each target signal separated by the separation processing unit 13A-5.

[0018] The data processing unit 14 performs clustering processing, tracking processing, etc. on the digital data supplied from the signal processing unit 13A (information relating to the position of each target estimated by the position estimation unit 13A-6) to detect the target. Information relating to the detected target is supplied to a higher-level device (not shown, for example, an ECU (Electric Control Unit)). The data processing unit 14 may be configured to be included in the higher-level device.

[0019] In this way, the radar device 100 separates the multiple received signals into target signals reflected from each target by the separation processing unit 13A-5, estimates the position of each target based on each target signal by the position estimation unit 13A-6, and performs object detection processing by the data processing unit 14 based on the estimation results.

[0020] Here, a case where the signal transmitting / receiving unit 11 is configured as a MIMO (multiple-input and multiple-output) will be described. In FIG. 2, two transmitting antennas Tx1 and Tx2 and four receiving antennas Rx1, Rx2, Rx3, and Rx4 are arranged. The radar device 100 can virtually form receiving antennas (in the example shown in FIG. 2, Rx5, Rx6, Rx7, and Rx8 are virtual receiving antennas) without changing the physical size, and can realize an aperture A2 formed by the receiving antennas Rx1, Rx2, Rx3, and Rx4 and the virtual receiving antennas Rx5, Rx6, Rx7, and Rx8. This aperture A2 is wider than the aperture A1 formed by the receiving antennas Rx1, Rx2, Rx3, and Rx4. Note that the arrangement example of the receiving antennas and transmitting antennas is not limited to that shown in FIG. 2. For example, the signal transmitting / receiving unit 11 may be configured with one transmitting antenna and eight receiving antennas (Tx1-Rx8). In this configuration, signals are received by sequentially switching among the eight receiving antennas. For example, the signal transmitting / receiving unit 11 may be configured with eight transmitting antennas and one receiving antenna (Tx8-Rx1). In this configuration, signals are transmitted by sequentially switching among the eight transmitting antennas.

[0021] Here, the procedure for transmitting and receiving signals by the signal transmitting and receiving unit 11 will be described. The signal transmitting and receiving unit 11 performs a process (first transmission and receiving process) in which it outputs a transmission signal from the transmitting antenna Tx1, and receives a reflected signal of this transmission signal reflected by a target at the receiving antennas Rx1, Rx2, Rx3, and Rx4 as a received signal. Thereafter, the signal transmitting and receiving unit 11 performs a process (second transmission and receiving process) in which it outputs a transmission signal from the transmitting antenna Tx2, and receives a reflected signal of this transmission signal reflected by a target at the receiving antennas Rx1, Rx2, Rx3, and Rx4. The signal transmitting and receiving unit 11 repeatedly performs the first transmission and receiving process and the second transmission and receiving process.

[0022] In the radar device 100, a transmission signal transmitted from the transmitting antenna Tx1 is reflected by a target, and this reflected signal is received by the receiving antenna Rx1 and processed as a signal on antenna channel ch1. In the radar device 100, a transmission signal transmitted from the transmitting antenna Tx1 is reflected by a target, and this reflected signal is received by the receiving antenna Rx2 and processed as a signal on antenna channel ch2. In the radar device 100, a transmission signal transmitted from the transmitting antenna Tx1 is reflected by a target, and this reflected signal is received by the receiving antenna Rx3 and processed as a signal on antenna channel ch3. In the radar device 100, a transmission signal transmitted from the transmitting antenna Tx1 is reflected by a target, and this reflected signal is received by the receiving antenna Rx4 and processed as a signal on antenna channel ch4. In the radar device 100, a transmission signal transmitted from the transmitting antenna Tx2 is reflected by a target, and this reflected signal is received by the receiving antenna Rx1 and processed as a signal on antenna channel ch5. In the radar device 100, a transmission signal transmitted from the transmitting antenna Tx2 is reflected by a target, and this reflected signal is received by the receiving antenna Rx2 and processed as a signal on antenna channel ch6. In the radar device 100, a transmission signal transmitted from the transmitting antenna Tx2 is reflected by a target, and this reflected signal is received by the receiving antenna Rx3 and processed as a signal on antenna channel ch7. In the radar device 100, a transmission signal transmitted from the transmitting antenna Tx2 is reflected by a target, and this reflected signal is received by the receiving antenna Rx4 and processed as a signal on antenna channel ch81. Note that the antenna channel ch numbers described above are merely examples, and may be changed as appropriate depending on the combination of receiving antennas and transmitting antennas.

[0023] Therefore, when the radar device 100 is configured with MIMO, it is possible to improve the target separation performance in the distance direction even when the aperture of the physically arranged receiving antenna is small and the bandwidth is narrow.

[0024] Here, a detailed configuration of the signal processing unit 13A will be described. The signal processing unit 13A includes an acquisition unit 13A-1, an extraction unit 13A-2, a calculation unit 13A-3, and an extension unit 13A-4 in addition to the separation processing unit 13A-5 and the position estimation unit 13A-6 described above.

[0025] The acquisition unit 13A-1 acquires first amplitude information for each received signal (antenna) with respect to the distance from a plurality of antennas (signal transmission / reception unit 11). For example, if the signal transmission / reception unit 11 is configured with two transmission antennas Tx1 and Tx2 and four reception antennas Rx1, Rx2, Rx3, and Rx4 (configured in MIMO), the acquisition unit 13A-1 acquires the first amplitude information from each antenna channel signal.

[0026] The first amplitude information I1 relative to the distance can be expressed in complex form by equation (1). In the FCM method employed in this embodiment, the first amplitude information can be obtained by Fourier transforming the received signal. I1=A0e iΨ ···(1)

[0027] A0 indicates the amplitude (real number), and Ψ indicates the phase of the first amplitude information. Such first amplitude information includes information on the reflected signal from the target distance. The acquisition unit 13A-1 acquires the first amplitude information from the signal received by each receiving antenna (each antenna channel signal). Note that the amplitude of each received signal with respect to time (including the case of complex amplitude) can be used as the first amplitude information with respect to distance.

[0028] The extraction unit 13A-2, as will be described in detail later, extracts first amplitude information corresponding to a predetermined distance from the multiple antennas (signal transmission / reception unit 11) for each antenna from the first amplitude information for each received signal acquired by the acquisition unit 13A-1 as information on the antenna channel signal (hereinafter, may be simply referred to as "antenna channel signal"). This antenna channel signal information is extracted for each antenna channel signal. As described above, when the amplitude of each received signal with respect to time is used as the first amplitude information with respect to distance, the first amplitude information of the received signal received at a predetermined time after transmitting the transmitted signal can be used as the first amplitude information corresponding to the predetermined distance.

[0029] The calculation unit 13A-3 calculates coefficients of an autoregressive model (hereinafter, sometimes referred to as "AR coefficients") based on information about the antenna channel signals.

[0030] The expansion unit 13A-4 performs arithmetic processing using an autoregressive model based on the antenna channel signal information and the coefficients (AR coefficients) of the autoregressive model, and estimates and expands the antenna channel signal information to the antenna direction. Here, the antenna direction will be described with reference to FIG. 3. The antenna channel signal information includes multiple pieces of information corresponding to the distance from the antenna. The antenna direction is the direction of the antenna channel expanded in processing by the expansion unit 13A-4, and is the direction indicated by X in FIG. 3. Furthermore, S1 indicates information corresponding to the distance contained in the signal of antenna channel ch1 (antenna channel signal information). S2 indicates information corresponding to the distance contained in the signal of antenna channel ch2 (antenna channel signal information). S3 indicates information corresponding to the distance contained in the signal of antenna channel ch3 (antenna channel signal information). S4 indicates information corresponding to the distance contained in the signal of antenna channel ch4 (antenna channel signal information). S5 indicates information corresponding to the distance contained in the signal of antenna channel ch5 (antenna channel signal information). S6 indicates information corresponding to the distance contained in the signal of antenna channel ch6 (antenna channel signal information). S7 indicates information corresponding to distance (antenna channel signal information) contained in the signal of antenna channel ch7. S8 indicates information corresponding to distance (antenna channel signal information) contained in the signal of antenna channel ch8. Sn indicates information corresponding to distance (antenna channel signal information) contained in the signal of antenna channel chn (extended nth antenna channel).

[0031] The separation processing unit 13A-5 performs a Fourier transform on the information of the extended antenna channel signal extended by the extension unit 13A-4 (hereinafter, may be simply referred to as "extended antenna channel signal"), thereby processing to separate the first amplitude information for each target. Note that the separation processing unit 13A-5 may also perform a Fourier transform on the information of the antenna channel signal extracted by the extraction unit 13A-2 and the information of the extended antenna channel signal extended by the extension unit 13A-4, thereby processing to separate the first amplitude information for each target.

[0032] Here, the processing of the radar device 100 according to the present invention will be described.

[0033] The one-dimensional (1D) column vector extracted from a memory (not shown) by the extraction unit 13A-2 as a signal for each antenna channel (antenna channel signal) of the j-th signal in the time series is shown in equation (2). In equation (2), N, which indicates the antenna channel, is used as a subscript, and in this embodiment, "N=8", but is not limited to "N=8". Each x of the column vector in equation (2) k (k=1 to N) is the distance R obtained by each antenna channel signal. j 1 shows the first amplitude information in (x1~x N ) j T ···(2)

[0034] Here, the AR coefficients are assumed to be one-dimensional column vectors, and an AR model is applied to this signal. Equation (3) shows the AR coefficients. Equation (4) shows an example of the AR model. (a1~a p ) j T ···(3) x n =a1x n-1 +a2x n-2 +···+a p x n-p ···(4)

[0035] The number p of AR coefficients represents the order of the AR model and corresponds to the number of targets that can be represented. In this embodiment, p=3. The order may be determined in advance, or may be determined using, for example, AIC (Akaike Information Criteria) or MDL (Minimum Description Length), as described on pages 139 and 148 of the literature (Kikuma Nobuyoshi, Adaptive Antenna Technology, First Edition, October 2003).

[0036] To calculate the AR coefficients, we formulate a matrix equation (equation (5)). b = XA (5)

number

[0037] The matrix size is as follows: b:(np) row 1 column X: (np) row p column A:p row 1 column

[0038] The calculation unit 13A-3 calculates the AR coefficients using a generalized inverse matrix of X. Here, a generalized inverse matrix other than the generalized inverse matrix of X may be used to calculate the AR coefficients. For example, when multiplied by the conjugate transpose (denoted by H) from the left, X H If X is regular, an inverse matrix exists, and the AR coefficients can be calculated by diagonalizing it. H b=X H Xa is called a normal equation. Therefore, X H A generalized inverse of X may be used.

[0039] The generalized inverse matrix can be calculated from the singular value decomposition of X. Equation (6) shows the singular value decomposition. Equation (7) shows the generalized inverse matrix. X=USV H ···(6) X + =VS + U H ···(7)

[0040] In this embodiment, the equation shown in Equation (7) has been described, but the equation may be formulated using a correlation matrix and the linear prediction method shown in the above-mentioned document may be used. Also, the AR coefficient may be calculated as a Yule-Walker equation.

[0041] The expansion unit 13A-4 estimates information about the antenna channel signal using the AR model of equation (4) based on the AR coefficients calculated by the calculation unit 13A-3 and the antenna channel signal, and expands the signal. The number of signals to be expanded can be determined based on the angle between the targets to be separated and the size of the antenna array (aperture, spacing, etc.). The expanded antenna channel signal is called an expanded antenna channel signal.

[0042] The separation processing unit 13A-5 performs FFT (Fast Fourier Transform) processing on the extended antenna channel signal to calculate an extended angular spectrum signal. The position estimation unit 13A-6 performs peak detection processing on the extended angular spectrum signal calculated by the separation processing unit 13A-5.

[0043] The radar device 100 performs FFT processing on the extended antenna channel signal using the separation processing unit 13A-5 to calculate an extended angular spectrum signal, and then detects peaks based on the extended angular spectrum signal using the position estimation unit 13A-6, thereby separating targets and more accurately determining the distance from the radar device 100 to the targets. Furthermore, by performing the above-mentioned processing on all antenna channels that make up the signal transmission / reception unit 11, the radar device 100 can also calculate (estimate) the azimuth angle of each target separately.

[0044] When the targets are stationary relative to the radar device 100, it is possible to estimate the position of each target based on the expanded angular spectrum signal calculated by the separation processing unit 13A-5. However, it is more preferable to perform peak detection by processing that detects extreme values ​​in the time series direction as described above, because this makes it possible to separate targets and estimate their positions even when the targets are moving relative to the radar device 100.

[0045] Next, a specific operation of the radar device 100 (particularly the signal processing unit 13A) will be described. Figures 4 and 5 are flowcharts showing the procedure of signal processing by the radar device 100. Figure 6 is a diagram explaining the configuration of the signal processing unit 13A related to the flowcharts shown in Figures 4 and 5.

[0046] The following describes an antenna channel signal acquisition step ST1 that acquires an antenna channel signal, which is a step before the signal processing by the signal processing unit 13A, an AR extension processing step ST2 that performs extension processing using AR, and a target signal separation processing step ST3 that performs separation processing of a target signal, all of which are performed by the signal processing unit 13A. First, the antenna channel signal acquisition step ST1 will be described in detail.

[0047] In step ST11, the signal transmitting / receiving unit 11 sets the number of the first antenna channel. In this step, the signal transmitting / receiving unit 11 sets i=0. "i=0" is, for example, antenna channel ch1.

[0048] In step ST12, the signal transmitting / receiving unit 11 starts radar measurement and transmits a signal (transmission signal).

[0049] In step ST13, the signal transmitting / receiving unit 11 receives the reflected signal reflected by the object as a received signal, and processes this received signal to obtain (generate) a time-series signal.

[0050] In step ST14, the signal transmitting / receiving unit 11 stores the time-series signals acquired in step ST13 in a memory (not shown) for each antenna channel.

[0051] In step ST15, the signal transmitting / receiving unit 11 increments the antenna channel number "i." Incrementing the antenna channel number "i" is expressed as "i=i+1."

[0052] In step ST16, the signal transmitting / receiving unit 11 determines whether the antenna channel number "i" updated in step ST15 has reached a predetermined number "N-1". N indicates the number of antenna channels, and is "8" in this embodiment, but is not limited to "8". If "i=N-1" (Yes), the process proceeds to step ST17, and if "i=N-1" is not true (No), the process returns to step ST12.

[0053] In step ST17, the signal transmitting / receiving unit 11 performs FFT processing on the time series signals for each antenna channel stored in the memory (distance FFT processing). By performing FFT processing on the time series signals, the time series signals are converted into distance signals.

[0054] In step ST18, the signal transmitting / receiving unit 11 completes the acquisition (generation) of distance signals for each antenna channel (hereinafter, sometimes referred to as "antenna channel signals"). All antenna channel signals are stored in a memory (not shown).

[0055] In this way, in the antenna channel signal acquisition step ST1, a transmission signal is transmitted, and the reflected signal is received as a received signal to acquire (generate) all antenna channel signals, and these signals are stored in a memory (not shown).

[0056] Next, the AR extension processing step ST2 will be described in detail.

[0057] In step ST21, the sequence extraction unit 15 sets the number "j" of the first antenna channel signal in the time series. In this step, the sequence extraction unit 15 sets j=0. The sequence extraction unit 15 corresponds to the acquisition unit 13A-1 and extraction unit 13A-2 described above.

[0058] In step ST22, the sequence extraction unit 15 extracts the set j-th antenna channel signal from the memory. The sequence extraction unit 15 transmits the extracted antenna channel signal to the AR coefficient calculation unit 16 and the signal extension unit 19. The AR coefficient calculation unit 16 corresponds to the calculation unit 13A-3 described above. The signal extension unit 19 corresponds to the extension unit 13A-4 described above.

[0059] In step ST23, the AR coefficient calculation unit 16 generates a matrix equation from the antenna channel signals transmitted from the sequence extraction unit 15. The matrix equation corresponds to the above-mentioned equation (7). The AR coefficient calculation unit 16 calculates AR coefficients from the generated equation based on the AR order (the number p of AR coefficients) stored in the storage unit 17. In this embodiment, p=3 is used for explanation, but is not limited to p=3.

[0060] In step ST24, the AR coefficient calculation unit 16 stores the AR coefficient calculated in the process of step ST23 in the AR coefficient storage unit 18. The AR coefficient storage unit 18 may be the same as the storage unit 17.

[0061] In step ST25, the signal extension unit 19 calculates an extended signal (hereinafter sometimes referred to as "extended antenna channel signal") that is estimated and extended in the antenna direction using an AR model based on the AR coefficients stored in the AR coefficient storage unit 18 and the antenna channel signals extracted by the sequence extraction unit 15. This extended signal is a signal that is extended by estimating a phase change for each antenna channel that depends on the target distance. The signal extension unit 19 corresponds to the extension unit 13A-4 described above.

[0062] In step ST26, the signal extension unit 19 stores the extension signals in the memory in the order of the antenna channels in which they are extended.

[0063] In step ST27, the sequence extraction unit 15 increments the antenna channel signal number "j." Incrementing the antenna channel signal number "j" is expressed as "j=j+1."

[0064] In step ST28, the sequence extraction unit 15 determines whether the number "j" of the antenna channel signal updated in step ST27 has reached a predetermined number "M-1". M indicates the number of samples of the antenna channel signal. If "j=M-1" (Yes), the process proceeds to step ST29, and if "j=M-1" is not true (No), the process returns to step ST22.

[0065] In step ST29, the signal processing unit 13A completes the acquisition (generation) of the extension signals (extension antenna channel signals) for the respective extended antenna channels. These extension antenna channel signals are stored in the memory.

[0066] In this way, in the AR extension processing step ST2, all the antenna channel signals acquired in the antenna channel signal acquisition step ST1 are AR extended to acquire extended antenna channel signals.

[0067] Next, the target signal separation processing step ST3 will be described in detail.

[0068] In step ST31, the FFT calculation unit 20 performs FFT processing on the extended antenna channel signal to calculate an angular spectrum signal. The FFT calculation unit 20 performs FFT processing on the extended antenna signal for each distance stored in memory in the antenna direction to calculate an angular spectrum signal for each distance. The FFT calculation unit 20 corresponds to the separation processing unit 13A-5 described above.

[0069] In step ST32, the peak detection unit 21 detects peaks from the absolute values ​​of the angular spectrum signal for each distance. The peak detection unit 21 corresponds to the position estimation unit 13A-6 described above. FIG. 7 is a diagram showing the results (range angle map) detected by the peak detection unit 21. FIG. 7 shows that two targets (target T11 and target T12) are positioned at different angles and different positions. The shading of the targets indicates the magnitude of the amplitude (peak height). FIG. 7 shows that target T11 has a higher amplitude than target T12. Note that if peaks can be detected from the angular spectrum signal calculated by the FFT calculation unit 20, step ST32 may be skipped.

[0070] In step ST33, the sequence extraction unit 22 extracts the extended antenna channel signal corresponding to the angle at which the peak was detected for an arbitrary distance range. As shown in FIG. 7, the arbitrary distance range is a distance range R1 at the angle at which the target T11 was detected and an arbitrary distance range R2 at the angle at which the target T11 was detected. Note that the arbitrary distance may be any distance range including 0 m, or may be a distance range such as 50 cm to 20 m. The extended antenna channel signal extracted in the process of step ST33 is a signal distinguished as a single target. The sequence extraction unit 22 corresponds to the above-mentioned position estimation unit 13A-6.

[0071] In step ST34, the memory 23 stores the extended antenna channel signals extracted in the process of step ST33 as signals distinguished as a single target. Note that the memory 23 may be the same as the storage unit 17.

[0072] In step ST35, the sequence extraction unit 22 determines whether or not extended antenna channel signals corresponding to all the peaks detected in the process of step ST32 have been extracted. If extended antenna channel signals corresponding to all the peaks have been extracted (Yes), the sequence extraction unit 22 proceeds to step ST36, and if extended antenna channel signals corresponding to all the peaks have not been extracted (No), the sequence extraction unit 22 returns to step ST33.

[0073] In step ST36, the signal processing unit 13A completes the acquisition (generation) of the signals distinguished as single targets. The memory 23 stores all of the signals distinguished as single targets.

[0074] In this way, in the AR extension processing step ST2, the radar device 100 applies AR processing to all antenna channel signals acquired in the antenna channel signal acquisition step ST1 to estimate phase changes for each antenna channel that depend on the target distance and generate extended antenna channel signals, and in the target signal separation processing step ST3, performs FFT processing on these extended antenna channel signals to separate targets in the distance direction. Thus, the radar device 100 can angularly separate targets that are close in the distance direction even with a small aperture, and can distance-separate targets even with a narrow band (improving distance accuracy).

[0075] (Regarding the second embodiment) Next, an embodiment will be described in which target-specific signals are reconstructed without performing the processing of expanding frequency-specific signal information using an AR model.

[0076] 8 is a block diagram showing the configuration of a radar device 300 according to the second embodiment. Note that the same components as those in the radar device 100 according to the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0077] The radar device 300 includes a signal transmitting / receiving unit 11, a signal processing unit 13B, and a data processing unit 14. The signal transmitting / receiving unit 11 receives signals reflected by one or more targets using multiple antennas arranged at different positions, either actually (physically) or virtually.

[0078] The signal processing unit 13B performs predetermined signal processing on the digital data stored in a memory (not shown) and supplies the result of the signal processing to the data processing unit 14. Specifically, the signal processing unit 13B includes a separation processing unit 13B-5 and a position estimation unit 13B-6.

[0079] The separation processing unit 13B-5 separates the multiple received signals into target signals reflected from each target based on the results of calculations performed using the multiple received signals received by the signal transmitting / receiving unit 11 and the coefficients of the autoregressive model.

[0080] The position estimation unit 13B-6 estimates the position of each target based on each target signal separated by the separation processing unit 13B-5.

[0081] The data processing unit 14 performs clustering processing, tracking processing, etc. on the digital data supplied from the signal processing unit 13B (information on the positions of each target estimated by the position estimation unit 13B-6) to detect the target. Information on the detected target is supplied to a higher-level device (e.g., ECU) not shown. The data processing unit 14 may be configured to be included in the higher-level device.

[0082] Here, a detailed configuration of the signal processing unit 13B will be described. In addition to the separation processing unit 13B-5 and position estimation unit 13B-6 described above, the signal processing unit 13B includes an acquisition unit 13B-1, an extraction unit 13B-2, a first calculation unit 13B-3, and a second calculation unit 13B-4.

[0083] The acquisition unit 13B-1 acquires first amplitude information for each received signal (antenna channel) relative to the distance from the multiple antennas (signal transmission / reception units 11). The acquisition unit 13B-1 has the same configuration as the acquisition unit 13A-1 of the radar device 100 according to the first embodiment.

[0084] The first amplitude information for distance includes amplitude information of a real component and amplitude information of an imaginary component. The acquisition unit 13B-1 acquires either or both of the amplitude information for distance and the phase information for distance for each antenna channel.

[0085] The extractor 13B-2 extracts, from the first amplitude information for each received signal (antenna channel) acquired by the acquirer 13B-1, first amplitude information corresponding to a predetermined distance from the plurality of antennas as antenna channel signal information for each antenna. The extractor 13B-2 has the same configuration as the extractor 13A-2 of the radar device 100 according to the first embodiment.

[0086] The first calculation unit 13B-3 calculates coefficients of an autoregressive model (AR coefficients) based on first amplitude information corresponding to a predetermined distance from the antenna.

[0087] The second calculation unit 13B-4 calculates phase information and second amplitude information corresponding to target signals reflected from one or more targets based on coefficients (AR coefficients) of an autoregressive model. In this embodiment, multiple targets are assumed, and the second calculation unit 13B-4 calculates phase information and second amplitude information corresponding to each target signal based on the AR coefficients. The second amplitude information means amplitude information corresponding to the target signal.

[0088] The separation processing unit 13B-5 reconstructs each target signal based on the phase information and second amplitude information of each target signal calculated by the second calculation unit 13B-4.

[0089] The position estimation unit 13B-6 reconstructs the target signal by the separation processing unit 13B-6 based on the phase information and second amplitude information of the target signal calculated by the second calculation unit 13B-4, and estimates the positions of one or more targets based on the reconstructed target signal. In this embodiment, multiple targets are assumed, and the position estimation unit 13B-6 estimates the position of each target based on the respective target signals reconstructed by the separation processing unit 13B-5.

[0090] In this way, the radar device 300 can reconstruct target-specific signals without performing processing to expand frequency-specific signal information using an AR model.

[0091] Next, the specific operation of the radar device 300 (particularly the signal processing unit 13B) will be described. Figures 9 and 10 are flowcharts showing the procedure of signal processing by the radar device 300. Figure 11 is a diagram used to explain the configuration of the signal processing unit 13B related to the flowcharts shown in Figures 9 and 10. Note that the same steps as those included in the procedure of signal processing by the radar device 100 according to the first embodiment explained using Figure 4 are assigned the same step numbers, and detailed explanations will be omitted.

[0092] Below, we will explain the antenna channel signal acquisition process ST4, which is a process before signal processing is performed by the signal processing unit 13B, which acquires an antenna channel signal, the target signal separation processing process ST5 by AR, which is performed by the signal processing unit 13B, and the distance / angle / amplitude processing process ST7.

[0093] The antenna channel signal acquisition step ST4 (steps ST41 to ST48) is the same as the antenna channel signal acquisition step ST1 (steps ST11 to ST18) in the signal processing procedure by the radar device 100 according to the first embodiment. Therefore, in the antenna channel signal acquisition step ST4, a transmission signal is transmitted, and the reflected signal is received as a received signal, thereby acquiring (generating) all antenna channel signals and storing these signals in a memory (not shown).

[0094] Next, the target signal separation processing step ST5 using AR will be described in detail.

[0095] In step ST51, the sequence extraction unit 15 sets the number "j" of the first antenna channel signal in the time series. In this step, the sequence extraction unit 15 sets j=0. The sequence extraction unit 15 corresponds to the acquisition unit 13B-1 and extraction unit 13B-2 described above.

[0096] In step ST52, the sequence extraction unit 15 extracts the j-th antenna channel signal of the set time series from the memory. The sequence extraction unit 15 transmits the extracted antenna channel signal to the AR coefficient calculation unit 16. The AR coefficient calculation unit 16 corresponds to the above-mentioned first calculation unit 13B-3.

[0097] In step ST53, the AR coefficient calculation unit 16 generates a matrix equation from the antenna channel signals transmitted from the sequence extraction unit 15. The matrix equation corresponds to the above-mentioned equation (5). The AR coefficient calculation unit 16 calculates AR coefficients from the generated equation based on the AR order (the number p of AR coefficients) stored in the storage unit 17. In this embodiment, the explanation will be given assuming p=3, but this is not limited to p=3.

[0098] In step ST54, the AR coefficient calculation unit 16 stores the AR coefficient calculated in the process of step ST53 in the AR coefficient storage unit 18. The AR coefficient storage unit 18 may be the same as the storage unit 17.

[0099] In step ST55, the characteristic polynomial calculation unit 31 generates a characteristic polynomial based on the AR coefficients stored in the AR coefficient storage unit 18, and calculates the roots. By calculating the roots, the characteristic polynomial calculation unit 31 can obtain phase information (phase terms) of the target-specific signals (target signals). The characteristic polynomial calculation unit 31 corresponds to the above-mentioned second calculation unit 13B-4.

[0100] In step ST56, the characteristic polynomial calculation unit 31 stores the phase information of the target-specific signals in the memory 32 in chronological order.

[0101] In step ST57, the target-specific amplitude calculation unit 33 generates a matrix equation for calculating second amplitude information (amplitude term) of the target-specific signal from the phase information of the target-specific signal and the antenna channel signal. Note that, hereinafter, the second amplitude information (amplitude term) of the target-specific signal may be referred to as the "target-specific amplitude signal." The target-specific amplitude calculation unit 33 corresponds to the above-mentioned second calculation unit 13B-4.

[0102] In step ST58, the target-specific amplitude calculation unit 33 calculates second amplitude information of the target-specific signal (target-specific amplitude signal) by the least squares method from the equation generated in the process of step ST57.

[0103] In step ST59, the target-specific amplitude calculation section 33 stores the second amplitude information of the target-specific signal (target-specific amplitude signal) calculated in the process of step ST58 in the memory 34 in chronological order.

[0104] In step ST60, the sequence extraction unit 15 increments the number "j" on the time series of the target-specific amplitude signals. The incrementing of the number "j" on the time series of the target-specific amplitude signals is expressed as "j=j+1."

[0105] In step ST61, the sequence extraction unit 15 determines whether the number (j) on the time series updated in the process of step ST60 has reached a predetermined number, "M-1." M indicates the number of samples on the time series. If "j=M-1" (Yes), the process proceeds to step ST62; if "j=M-1" is not true (No), the process returns to step ST52.

[0106] In step ST62, the signal processing unit 13B completes the acquisition of the target-specific signals (target signals). The memory 34 stores the target signals.

[0107] Next, a specific calculation process procedure of the target signal separation process step ST5 using AR will be described.

[0108] The characteristic polynomial generated in step ST55 is a polynomial having AR coefficients for the time series "j" as shown in equation (8). s(v)=a1v 1 + a2v 2 +···+a p v p -1 (8)

[0109] The characteristic polynomial described above is a polynomial for finding the eigenvalues ​​of the associated matrix shown in equation (9) from the AR coefficients. The eigenvalues ​​are found by diagonalizing this. These eigenvalues ​​are the roots λ of the characteristic polynomial with p values. m (m is an integer between 1 and p).

number

[0110] In addition, a vertical vector that lists the amplitudes for each target is placed as shown in equation (10). (B1~B p ) j T ···(10)

[0111] p roots λ of the characteristic polynomial m Create a matrix of powers (m is an integer between 1 and p) and consider the equation shown in equation (11).

number

[0112] By solving this equation, the target-specific amplitude B m The roots λ of the characteristic polynomial p can be estimated. m and target-specific amplitude B m The signal with the target separated can be reconstructed from the equation. The least squares method can be used to solve this equation, for example.

[0113] Next, the distance / angle / amplitude processing step ST7 will be described.

[0114] In step ST71, the distance / angle / amplitude evaluation processing unit 36 ​​sets the number "k" of the first target. In this step, the distance / angle / amplitude evaluation processing unit 36 ​​sets the number of the first target to k=0. The distance / angle / amplitude evaluation processing unit 36 ​​corresponds to the separation processing unit 13B-5 and the position estimation unit 13B-6 described above.

[0115] In step ST72, the distance / angle / amplitude evaluation processing unit 36 ​​performs distance evaluation processing by chronologically extracting the second amplitude information of the target-specific signal (target-specific amplitude signal) from the memory 34. Fig. 12 is a diagram showing the results of distance evaluation processing when the number of targets is assumed to be three (targets T21, T22, and T23). Note that the waveforms of each target shown in Fig. 12 are shown as smooth curves, but this is just an example and is not limited to smooth curves.

[0116] In step ST73, the distance / angle / amplitude evaluation processing unit 36 ​​calculates the angle spectrum from the phase information (phase term) of the target-specific signal at the corresponding distance, and performs angle evaluation processing. Fig. 13 is a diagram showing the results of angle evaluation processing when the number of targets is assumed to be three (targets T21, T22, and T23).

[0117] In step ST74, the distance / angle / amplitude evaluation processing unit 36 ​​stores the amplitude, distance, and angle of the target in a memory (not shown). Specifically, the distance / angle / amplitude evaluation processing unit 36 ​​stores the amplitude and distance of the target obtained as a result of the distance evaluation processing in step ST72, and the angle of the target obtained as a result of the angle evaluation processing in step ST73 in the memory.

[0118] In step ST75, the distance / angle / amplitude evaluation processing unit 36 ​​increments the target number "k." The incrementing of the target number "k" is expressed as "k=k+1."

[0119] In step ST76, the distance / angle / amplitude evaluation processing unit 36 ​​determines whether the target number "k" updated in step ST75 has reached a predetermined number "P-1", where P indicates the number of targets. If "k=P-1" (Yes), the process proceeds to step ST77, and if "k=P-1" is not true (No), the process returns to step ST72.

[0120] In step ST77, the distance / angle / amplitude evaluation processing unit 36 ​​completes the acquisition of profiles for all targets.

[0121] In this way, in the target signal separation processing step ST5 using AR, the radar device 300 generates a characteristic polynomial from the AR coefficients, finds roots to calculate phase information of the target-specific signals, calculates second amplitude information of the target-specific signals by performing a least-squares calculation using the phase information of the target-specific signals and the measurement data, performs distance evaluation processing on the second amplitude information of the target-specific signals (target-specific amplitude signals) in a time series, and calculates an angular spectrum from the phase information of the target-specific signals and performs angle evaluation processing, thereby calculating the amplitude, distance, and angle of the target. Therefore, the radar device 300 can angularly separate targets close in the distance direction even with a small aperture, and can distance-separate targets even with a narrow bandwidth (improving distance accuracy). Note that the memories 32 and 34 may not be included. In this configuration, the characteristic polynomial calculation unit 31 transmits the phase information of the target-specific signals to the target-specific amplitude calculation unit 33 in chronological order. Furthermore, the target-specific amplitude calculation unit 33 transmits the second amplitude information of the target-specific signal (target-specific amplitude signal) and the phase information of the target-specific signal (phase term) to the distance / angle / amplitude evaluation processing unit .

[0122] (About object detection method) Next, an object detection method for the radar device 100 that improves target separation performance in the distance direction even in a narrow band will be described. Fig. 14 is a flowchart showing the steps of the object detection method that improves target separation performance in the distance direction even in a narrow band.

[0123] In step ST101, the signal transmitting / receiving unit 11 receives signals reflected by one or more targets using a plurality of antennas arranged at different positions, either actually or virtually (signal transmitting / receiving step).

[0124] In step ST102, the separation processing units 13A-5 and 13B-5 separate the angles of the targets based on the results of calculations performed using the signals received by the multiple antennas and the coefficients of the autoregressive model (separation processing step).

[0125] According to this configuration, the object detection method can separate the multiple received signals into target signals reflected from each target by the separation processing step. Therefore, the object detection method can angularly separate targets that are close in the distance direction even with a small aperture, and can distance-separate targets even with a narrow band (improving distance accuracy).

[0126] (About the program) The program for improving the target separation performance in the distance direction even in a narrow band mainly comprises the following steps, and is executed by the computer 500 (hardware).

[0127] Step 1 (signal transmitting / receiving step): A step of receiving signals reflected by one or more targets by a plurality of antennas arranged at different positions, either actually or virtually. Step 2 (separation processing step): A step of separating the angles of the target based on the results of calculations performed using the signals received by the multiple antennas and the coefficients of the autoregressive model.

[0128] Here, the configuration and operation of the computer 500 will be described with reference to Fig. 15. Fig. 15 is a diagram showing the configuration of the computer 500. As shown in Fig. 15, the computer 500 is configured by connecting a processor 501, a memory 502, a storage 503, an input / output I / F 504, and a communication I / F 505 on a bus A. The functions and / or methods described in this disclosure are realized by the cooperation of these components.

[0129] The memory 502 is configured by a RAM (Random Access Memory). The RAM is configured by a volatile memory or a non-volatile memory.

[0130] The storage 503 is configured with a ROM (Read Only Memory). The ROM is configured with a non-volatile memory, and is realized by, for example, an HDD (Hard Disc Drive), an SSD (Solid State Drive), or a flash memory. The storage 503 stores various programs, such as the programs realized in the above-described steps 1 and 2.

[0131] A signal processing circuit 600 is connected to the input / output I / F 504. One or more transmitting antennas 601 and one or more receiving antennas 602 are connected to the signal processing circuit 600. Here, a variety of configurations of the transmitting antennas and receiving antennas are possible. The signal processing circuit 600, the transmitting antenna 601, and the receiving antenna 602 correspond to the signal transmitting / receiving unit 11 described above.

[0132] The processor 501 controls the overall operation of the computer 500. The processor 501 is an arithmetic unit that loads an operating system and various programs that implement various functions from a storage 503 into a memory 502 and executes instructions contained in the loaded programs.

[0133] Specifically, when processor 501 receives a user operation, it reads a program (for example, a program according to the present invention) stored in storage 503, loads the read program into memory 502, and executes the program. Furthermore, by processor 501 executing the processing program, various functions such as signal processing unit 13A and data processing unit 14 are realized.

[0134] Here, we will explain the configuration of the processor 501. The processor 501 is realized by, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), various other arithmetic devices, or a combination of these.

[0135] Furthermore, to realize the functions and / or methods described in the present disclosure, some or all of the functions of the processor 501, memory 502, storage 503, etc. may be configured by a computer (hereinafter referred to as a processing circuit) 700, which is dedicated hardware. FIG. 16 is a diagram showing the configuration of the processing circuit 700. The processing circuit 700 is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. A signal processing circuit 600 is connected to the processing circuit 700. One or more transmitting antennas 601 and one or more receiving antennas 602 are connected to the signal processing circuit 600.

[0136] Furthermore, although the processor 501 has been described as a single component, the present invention is not limited to this and may be configured as a set of multiple physically separate processors. In this specification, a program described as being executed by the processor 501 or instructions included in the program may be executed by a single processor 501, or may be distributed and executed by multiple processors. Furthermore, a program executed by the processor 501 or instructions included in the program may be executed by multiple virtual processors.

[0137] The communication I / F 505 is an interface that complies with a predetermined communication standard (for example, CAN (Controller Area Network)), and communicates with an external higher-level device (for example, an ECU) via wire or wirelessly.

[0138] In this way, the program according to this embodiment is executed by the computer 500, 700, and by using the signal processing circuit 600, the transmitting antenna 601, and the receiving antenna 602, signals reflected by one or more targets are received by multiple antennas arranged at different locations, either actually or virtually, in step 1 (signal transmitting and receiving step), and processing is performed to separate the angles of the targets based on the results of calculations performed using the respective received signals received by the multiple antennas and the coefficients of the autoregressive model in step 2 (separation processing step). Thus, by executing the program according to this embodiment on the computer 500, 700, and using the signal processing circuit 600, the transmitting antenna 601, and the receiving antenna 602, targets close in the distance direction can be separated in terms of angle even with a small aperture, and distance separation of targets can be performed even with a narrow band (improving distance accuracy).

[0139] Although some of the embodiments of the present application have been described in detail above with reference to the drawings, these are merely examples, and the present invention can be implemented in other forms that have undergone various modifications and improvements based on the knowledge of those skilled in the art, including the aspects described in the disclosure of the present invention. [Explanation of symbols]

[0140] 11 Signal transmitter / receiver 13A, 13B Signal processing section 13A-1,13B-1 Acquisition Department 13A-2,13B-2 Extraction part 13A-3 Calculation part 13A-4 Extension 13A-5, 13B-5 Separation processing section 13A-6,13B-6 Position estimation part 13B-3 1st calculation part 13B-4 2nd calculation part 14 Data processing section 15,22 Sequence extraction section 16 AR coefficient calculation section 17 Memory section 18 AR coefficient storage section 19 Signal extension section 20 FFT calculation section 21 Peak detector 23, 32, 34 Memory 31 Characteristic polynomial calculation section 33 Target-specific amplitude calculation section 36 Distance, angle, and amplitude evaluation processing section 100,300 radar equipment

Claims

1. a signal transmitting / receiving unit that receives signals reflected by one or more targets using a plurality of antennas that are actually or virtually located at different positions; an acquisition unit that acquires first amplitude information with respect to a distance from the plurality of antennas for each of the received signals; an extracting unit that extracts, from the first amplitude information for each of the received signals acquired by the acquiring unit, the first amplitude information corresponding to a plurality of predetermined distances from the plurality of antennas as information of an antenna channel signal; a calculation unit that represents first amplitude information obtained from the plurality of antennas by an autoregressive model of a predetermined order based on the information of the antenna channel signals extracted by the extraction unit, and calculates coefficients of the autoregressive model using a generalized inverse matrix or an autocorrelation function; a separation processing unit that separates the angles of the targets based on a calculation result performed using each of the received signals received by the plurality of antennas and the coefficients of the autoregressive model calculated by the calculation unit. an extension unit that estimates and extends the information of the antenna channel signal in an antenna direction based on the information of the antenna channel signal and a coefficient of the autoregressive model; The radar device according to claim 1 , wherein the separation processing unit performs a Fourier transform on information of the extended antenna channel signal extended by the extension unit, thereby separating the first amplitude information for each target.

3. a second calculation unit that calculates phase information and second amplitude information corresponding to the target signals reflected from the one or more targets based on the coefficients of the autoregressive model; 2. The radar device according to claim 1, further comprising: a position estimation unit that reconstructs a target signal by the separation processing unit based on the phase information and the second amplitude information of the target signal calculated by the second calculation unit, and estimates positions of the one or more targets based on the reconstructed target signal.

4. a signal transmitting and receiving step of receiving signals reflected by one or more targets by a plurality of antennas disposed at different positions, either actually or virtually; an acquisition step of acquiring first amplitude information with respect to a distance from the plurality of antennas for each of the received signals; an extraction step of extracting, as information on antenna channel signals, the first amplitude information corresponding to a plurality of predetermined distances from the plurality of antennas from the first amplitude information for each of the received signals acquired in the acquisition step; a calculation step of expressing first amplitude information obtained from the plurality of antennas by an autoregressive model of a predetermined order based on the information of the antenna channel signals extracted in the extraction step, and calculating coefficients of the autoregressive model using a generalized inverse matrix or an autocorrelation function; a separation processing step of separating the angles of the target based on a calculation result performed using each of the received signals received by the plurality of antennas and the coefficients of the autoregressive model calculated in the calculation step.

5. On the computer, a signal transmitting and receiving step of receiving signals reflected by one or more targets by a plurality of antennas disposed at different positions, either actually or virtually; an acquisition step of acquiring first amplitude information with respect to a distance from the plurality of antennas for each of the received signals; an extraction step of extracting, as information on antenna channel signals, the first amplitude information corresponding to a plurality of predetermined distances from the plurality of antennas from the first amplitude information for each of the received signals acquired in the acquisition step; a calculation step of expressing first amplitude information obtained from the plurality of antennas by an autoregressive model of a predetermined order based on the information of the antenna channel signals extracted in the extraction step, and calculating coefficients of the autoregressive model using a generalized inverse matrix or an autocorrelation function; a separation processing step of separating the angles of the target based on the calculation results performed using the signals received by the plurality of antennas and the coefficients of the autoregressive model calculated in the calculation step.

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