阅读说明：本技术 一种快速的多发多收的阵列校正系统及方法 (Rapid multi-transmitting multi-receiving array correction system and method ) 是由 黄勇 杨晓飞 王宏达 许冰 于 2019-10-12 设计创作，主要内容包括：本发明涉及雷达技术领域,具体地说,是一种快速的多发多收的阵列校正系统及方法,解决MIMO阵列系统、尤其是均匀线阵中多天线和多收发通道由于通道间耦合导致的幅度和相位不一致的问题,包括多发多收阵列雷达,雷达信号接收和转发分系统,校正计算和验证单元；多发多收阵列雷达由多通道发射机,发射天线阵列,接收天线阵列,多通道接收机,信号处理机和总线通讯控制器构成,包括M个发射机通道和发射天线通道,N个接收机通道和接收天线通道,其中发射通道个数M接收通道个数N根据用户需要选择,根据不同的发射通道和接收通道数,以及不同的波形体制可以做简单阵列,分时MIMO,正交波形分集MIMO等,本实施例中采用分时MIMO体制。(The invention relates to the technical field of radars, in particular to a quick multi-transmitting and multi-receiving array correction system and a quick multi-transmitting and multi-receiving array correction method, which solve the problem of inconsistent amplitude and phase caused by coupling among channels of a multi-antenna and a multi-transmitting channel in an MIMO array system, especially a uniform linear array, and comprise a multi-transmitting and multi-receiving array radar, a radar signal receiving and forwarding subsystem and a correction calculation and verification unit; the multiple-transmitting multiple-receiving array radar comprises a multi-channel transmitter, a transmitting antenna array, a receiving antenna array, a multi-channel receiver, a signal processor and a bus communication controller, and comprises M transmitter channels, M transmitting antenna channels, N receiver channels and N receiving antenna channels, wherein the number of the transmitting channels, M, of the receiving channels, N, is selected according to user requirements, simple arrays, time-sharing MIMO, orthogonal waveform diversity MIMO and the like can be manufactured according to different numbers of the transmitting channels and the receiving channels and different waveform systems, and a time-sharing MIMO system is adopted in the embodiment.)

1. A rapid array channel correction system with multiple transmitting and multiple receiving functions comprises a multiple transmitting and multiple receiving array radar, a radar signal receiving and forwarding subsystem, a rotation control unit and a correction calculation and verification unit, and is characterized in that: the multi-transmitting and multi-receiving array radar comprises a multi-channel transmitter, a transmitting antenna array, a receiving antenna array, a multi-channel receiver, a signal processor and a bus communication controller; the rotation control unit comprises a rotary table and a high-precision rotary table controller; the multi-transmitting and multi-receiving array radar is fixed on the rotary control unit, the radar signal receiving and forwarding subsystem is fixed at the other end of the darkroom, and the distance between the rotary control unit and the radar signal receiving and forwarding subsystem meets the far field condition; the bus communication controller of the multiple-input multiple-output array radar is connected with the correction calculation and verification unit; the radar signal receiving and forwarding subsystem is composed of a receiving horn antenna, a transmitting horn antenna, a microwave front-end module, a signal processing and communication module, a power supply module, a metal shell and a protective cover.

2. The system of claim 1, wherein the rotation control unit comprises a turntable and a turntable controller, the turntable is a mechanical device with two-dimensional rotation of pitch and azimuth, the turntable has a pitch range of-80 ° to +80 °, a scale accuracy of 0.1 °, an azimuth range of-120 ° to +120 °, and a scale accuracy of 0.1 °; the rotary table controller is used for controlling the rotary table to rotate according to the accuracy requirement, and controlling the rotation range and the rotation step of the azimuth or the pitching through a Graphical User Interface (GUI).

3. A fast multi-transmit-multi-receive array calibration method using the fast multi-transmit-multi-receive array channel calibration system as claimed in claim 2, wherein the steps of implementing amplitude and phase error calibration for M × N virtual channels are as follows:

the method comprises the following steps: acquiring echo signal information;

step two: calculating a correction matrix and an array element interval;

step three: verifying the correction matrix;

the specific process of the first step is as follows:

1a) the zero point on the rotation control unit is aligned with the centers of the transmitting horn antenna and the receiving horn antenna of the radar signal receiving and forwarding subsystem, and the consistency of the pitching and the azimuth of the receiving horn antenna is ensured;

1b) setting a target speed of 5m/s and a rotary table rotation speed of 1 DEG/s on an interface of a correction calculation and verification unit, and respectively transmitting two groups of data to a radar signal receiving and forwarding subsystem and a state controller of a rotation control unit through a CAN bus;

1c) after receiving the instruction, the multiple-transmitting and multiple-receiving array radar and radar signal receiving and forwarding subsystem starts to work, and then a rotary table of the rotary control unit starts to work;

1d) the multi-sending and multi-receiving radar performs constant false alarm detection and target detection on complex planes after Fast Fourier Transform (FFT) of 3 x 4 virtual channels at each angle of preset and selected 9 directions, and transmits 12 complex FFT data corresponding to target points in accordance with set speed and distance to a correction calculation and verification unit through a bus;

the specific flow of the second step is as follows:

2a) the correction calculation and verification unit stores the angle target echo signal fixedly calculated each time in SDRAM, and starts to calculate a correction matrix after the rotation control unit finishes traversing of all 9 angles;

2b) arranging a complex number of 10 frames and 12 channels of 9 angles into a complex plane, wherein each row is a complex number of 12 channels and 10 frames, each 12 complex numbers form a group and are frame data of 12 channels, the total number of 10 frames is 120 complex numbers, and each column is a complex value of the same channel under 9 different angles;

2c) estimating a 12 x 12 correction matrix and the spacing of a total of 12 virtual receiving array elements;

the specific process of the third step is as follows:

3a) the correction calculation and verification unit sends a verification angle instruction to the rotation control unit;

3b) the rotation control unit verifies the angle measurement result every 5 degrees and compares the angle measurement result with the true value;

3c) after traversing all verification angles, if the error of each angle and the true value is within the specified range of 1 degree, the verification is finished, and the correction matrix and the array element interval are estimated correctly;

3d) if the angle does not meet the error requirement, re-correcting, and returning to the step (1); if the correction is not satisfied twice, the part is regarded as a bad part, and the radar is replaced.

4. The method as claimed in claim 3, wherein in the step 2c), a 12 x 12 calibration matrix and a total spacing of 12 virtual receiving array elements are estimated, and the method comprises:

firstly, initializing phases among channels and intervals among array elements, and setting the initial phases and the initial intervals to be 0; secondly, rearranging the complex plane of 2b) into a three-dimensional matrix, wherein the first dimension (row) is 9 different angles, the second dimension (column) is 12 different channels, the third dimension (page) is 10 different frames of data, firstly calculating the phase difference between the different channels for each frame of data, and uncoiling; performing linear interpolation on the actual phase difference and the theoretical difference which are solved among 12 channels of each frame of data again, and performing estimation on the difference as the interval error of each frame of array elements; and establishing an amplitude diagonal matrix again, and processing the data under the angles of 9 channels of 12 channels per frame as follows:

wherein the data_uncal8Is a two-dimensional matrix of 9 x 12, and Am is_matrixAnd finally, a correction matrix of the signal estimation of the frame is obtained from the shaped echo signal and the expected echo signal by using a least square method, and the correction matrix of each frame and the estimation value of the array element spacing are averaged to obtain the expected correction matrix and the array element spacing.

Technical Field

The invention relates to the technical field of radar, in particular to a quick multi-transmitting multi-receiving array correction system and a quick multi-transmitting multi-receiving array correction method, which are used for correcting channel errors in a multi-transmitting multi-receiving (MIMO) multi-antenna array radar and solving the problem of inconsistent amplitude and phase caused by coupling among channels of a multi-antenna and a multi-transmitting channel in an MIMO array system, especially a uniform linear array.

Background

At present, in the technical field of radar array correction at home and abroad, the coupling correction for correcting a transmitting or receiving system is generally a separate correction method. Common calibration methods are an injection reference source method and a blind calibration method.

Leo Gui Sheng et al, in his patent application document, "a method for multiple input multiple output radar system array error self-correction" (publication No. CN101251597A), discloses a method for multiple input multiple output radar system array error self-correction. The method is used for self-correcting the amplitude and phase errors depending on the orientation of the receiving array on the premise that the transmitting array of the multi-input multi-output radar system is corrected. The method comprises the steps of utilizing 2 corrected transmitting array elements of a multi-input multi-output radar system to transmit mutually orthogonal signals, then utilizing the orthogonality of the transmitting signals to separate echo signals of all the transmitting array elements by a matched filtering method, utilizing the echo signals to construct an autocorrelation matrix and a cross-correlation matrix, utilizing a rotation invariant subspace method to estimate a real steering vector and a target angle of an array, and finally utilizing the estimated real steering vector and the target angle of the array to achieve the purpose of correcting the array azimuth-dependent amplitude phase error. The method can only correct the amplitude phase consistency of the receiving channels and compensate and correct the coupling between the receiving channels. The coupling and amplitude phase consistency of the transmitting channel cannot be compensated simultaneously, the system is complex, the signal orthogonality of the transmitting channel has a large influence on the final correction, and the orthogonality of the transmitting signal in the transmitting channel is difficult to ensure.

A blind correction device is disclosed in the document "ABLind Calibration Method for an Adaptive Array antenna in DS-CDMA System Using an MMSEAlgorithm" (VTC 2000-Spring Tokyo.2000 IEEE 51st, Vol 1, page 21) by S.Kobayakawa, M.Tsutsui and Y.tanaka et al. The device adopts a self-adaptive algorithm to carry out iterative operation on a reference signal obtained by direct coupling of a transmitting antenna channel and a sampling signal passing through each radio frequency channel of a transmitting antenna, thereby obtaining a correction weight of each transmitting channel. Blind correction methods are demanding on the environment in which they are used and the signal data that are collected. The method requires that reference signal data obtained by direct coupling of transmitting antenna channels and sampling data passing through each radio frequency channel of the transmitting antenna are strictly synchronous, otherwise, a self-adaptive iterative algorithm is diverged, and the aim of correction cannot be achieved.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a quick receiving and transmitting channel joint correction system and a method for correcting the coupling and amplitude-phase errors of the receiving and transmitting channels by using the system. Therefore, the amplitude-phase response of each transmitting-receiving channel in the MIMO array can be consistent.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a rapid multi-transmitting and multi-receiving array channel correction system comprises a multi-transmitting and multi-receiving array radar, a radar signal receiving and forwarding subsystem, a rotation control unit and a correction calculation and verification unit. The multiple-input multiple-output array radar comprises a multi-channel transmitter, a transmitting antenna array, a receiving antenna array, a multi-channel receiver, a signal processor and a bus communication controller. The rotation control unit includes a turntable and a high-precision turntable controller. The multi-transmitting and multi-receiving array radar is fixed on the rotary control unit, the radar signal receiving and forwarding subsystem is fixed at the other end of the darkroom, and the distance between the rotary control unit and the radar signal receiving and forwarding subsystem meets the far field condition. The bus communication controller of the multiple-transmitting and multiple-receiving array radar is connected with the correction calculation and verification unit. The radar signal receiving and forwarding subsystem consists of a receiving horn antenna, a transmitting horn antenna, a microwave front-end module, a signal processing and communication module, a power supply module, a metal shell and a protective cover. The receiving horn antenna receives signals transmitted by the multi-transmitting and multi-receiving array radar, the signals are converted into intermediate frequency signals through the microwave front-end module, the signal processing and communication module receives control of the correction calculation and verification unit, the intermediate frequency signals are modulated through signal processing and additional Doppler frequency and then sent to the microwave front-end module, and the signals are transmitted out through the transmitting horn antenna after the microwave front-end module performs up-conversion. After the multi-transmitting and multi-receiving radar receives the transmitting signal of the radar signal receiving and forwarding subsystem, the target point is extracted and transmitted to the correction calculation and verification unit through the bus communication controller. And after the correction matrix is calculated by the correction calculation and verification unit, the correction matrix is written into the multi-sending and multi-receiving array radar through the CAN bus. The rotary control unit controls the rotary table to rotate, and whether the radar angle measurement precision meets the requirement is verified, so that whether the correction is successful is determined.

The invention is further improved, the rotation control unit comprises a rotary table and a rotary table controller, the rotary table is a mechanical device with pitching and azimuth two-dimensional rotation, the pitching range of the rotary table is from-80 degrees to +80 degrees, the scale precision is 0.1 degree, the azimuth range is from-120 degrees to +120 degrees, and the scale precision is 0.1 degree; the rotary table controller is used for controlling the rotary table to rotate according to the accuracy requirement and controlling the rotation range and the rotation step of the azimuth or the pitching through a Graphical User Interface (GUI).

The invention also discloses a rapid multi-transmission multi-reception array correction method, which comprises the following steps of using the system to perform rapid amplitude and phase error correction on M transmitting channels and N receiving channels through time-sharing MIMO virtual M x N receiving channels:

obtaining echo signal information

1a) The zero point on the rotation control unit is aligned with the center of the transmitting horn antenna and the receiving horn antenna of the radar signal receiving and forwarding subsystem, so that the consistency of the pitch and the azimuth of the receiving horn antenna is ensured

1b) And setting a target speed Vm/s and a rotary table rotation speed K DEG/s on an interface of the correction calculation and verification unit, and respectively transmitting the two groups of data to a radar signal receiving and forwarding subsystem and a state controller of a rotation control unit through a CAN bus.

1c) And after receiving the command, the multiple-transmitting and multiple-receiving array radar and radar signal receiving and forwarding subsystem starts to work. After which the turntable of the rotation control unit starts to operate.

1d) The multi-sending and multi-receiving radar performs constant false alarm detection and target detection on a complex plane after Fast Fourier Transform (FFT) of M x N virtual channels at each angle of preset and selected 9 directions, and transmits M x N complex FFT data corresponding to a target point with set speed and distance to a correction calculation and verification unit through a bus.

Calculating correction matrix and array element spacing

2a) The calibration calculation and verification unit stores target echo signals of different angles in SDRAM, and starts to calculate a calibration matrix after the rotation control unit completes traversal of all angles.

2b) Arranging the complex numbers of different channels of different frames of each angle into a complex plane, wherein each row is the complex number of different channels and different frames, and each column is the complex number value under different angles.

2c) And estimating (M N) correction matrix and virtual receiving array element spacing.

2d) And writing the estimated correction matrix and array element spacing into the multi-transmitting and multi-receiving radar through a bus.

Verifying a correction matrix

3a) The correction calculation and verification unit sends a verification angle instruction to the rotation control unit.

3b) The rotation control unit verifies the angle measurement result every L degrees and compares the angle measurement result with the true value.

3c) After all verification angles are traversed, if the error of each angle and the true value is in a specified range, the verification is completed, and the correction matrix and the array element spacing are estimated correctly.

3d) And (4) if the angle does not meet the error requirement, re-correcting and returning to the step (1). If the correction is not satisfied twice, the part is regarded as a bad part, and the radar is replaced.

In the above flow of step 2c), a 12 × 12 correction matrix and the total spacing between 12 virtual receiving array elements are estimated, and the method adopted is as follows:

firstly, initializing phases among channels and intervals among array elements, and setting the initial phases and the initial intervals to be 0; secondly, rearranging the complex plane of 2b) into a three-dimensional matrix, wherein the first dimension (row) is 9 different angles, the second dimension (column) is 12 different channels, the third dimension (page) is 10 different frames of data, firstly calculating the phase difference between the different channels for each frame of data, and uncoiling; performing linear interpolation on the actual phase difference and the theoretical difference which are solved among 12 channels of each frame of data again, and performing estimation on the difference as the interval error of each frame of array elements; and establishing an amplitude diagonal matrix again, and processing the data under the angles of 9 channels of 12 channels per frame as follows:

wherein the data_uncal8Is a two-dimensional matrix of 9 x 12, and Am is_matrixAnd finally, a correction matrix of the signal estimation of the frame is obtained from the shaped echo signal and the expected echo signal by using a least square method, and the correction matrix of each frame and the estimation value of the array element spacing are averaged to obtain the expected correction matrix and the array element spacing.

The invention has the beneficial effects that: compared with the prior art, the invention has the following advantages:

(1) the invention corrects the transmitting channels including the transmitting antenna channel and the receiving channels including the receiving antenna channel, and a correction matrix corrects the coupling of the transmitting and receiving channels and the inconsistency of the amplitude and the phase between the channels, overcomes the defect that the transmitting antenna channel or the receiving channel is respectively corrected in the prior art, ensures that the amplitude-phase response of each channel is more consistent, simplifies the complexity of the construction of a test environment and a test system, and saves the test time.

(2) The channel correction method of the invention fully utilizes the transmitting signal of the transmitting channel as the calibration signal, overcomes the defect that the prior method must inject the calibration signal into each channel in a time-sharing way, can ensure the consistency of the characteristic parameters of the calibration signal in a plurality of transmitting and receiving channels, and ensures that the obtained error correction coefficient is more accurate.

(3) The radar signal receiving and forwarding subsystem can adjust the transmitting power and the signal superposition Doppler frequency, so that the radar signal receiving and forwarding subsystem has no strict requirements on the applied environment and the correction signal and has wider application range.

(4) The channel correction method and the verification scheme only need to select fixed angles in the range of the radar azimuth angle, greatly save the calculation time, reduce the use of equipment and overcome the defect that the traditional method is complicated in calculating the correction coefficient of a system.

Drawings

FIG. 1 is a block diagram of the system of the present invention.

FIG. 2 is a block diagram of a radar signal receiving and transmitting subsystem according to the present invention.

FIG. 3 is a block diagram of a calibration calculation and verification unit according to the present invention.

FIG. 4 is a flow chart of the method of the present invention.

Detailed Description

For the purpose of enhancing the understanding of the present invention, the present invention will be described in further detail with reference to the accompanying drawings and examples, which are provided for the purpose of illustration only and are not intended to limit the scope of the present invention.