Amplitude and phase correction method for receiving channel of multi-antenna GNSS receiver

Abstract

The invention discloses a multi-antenna GNSS (Global Navigation Satellite System) receiver receiving channel amplitude-phase correction method, which comprises the following steps of: firstly, defining an array signal model, taking a first channel of a multi-antenna GNSS receiver as a reference channel, introducing received signal data into the array signal model to obtain model data, and correcting the amplitude-phase of the receiving channels of the multi-antenna GNSS receiver according to the array signal model and frequency characteristics of signals received by each channel; judging amplitude-phase response fluctuation of each channel; when the fluctuation of the amplitude-frequency response in the bandwidth is not greater than a set fluctuation threshold value, finishing correction of a channel amplitude error and a channel phase error by adopting a dot frequency amplitude-phase error correction method; and when the fluctuation of the amplitude-frequency response in the bandwidth is greater than a set fluctuation threshold value, completing correction of a channel amplitude error and a channel phase error by adopting a channel equalization technology correction method. According to the amplitude-frequency response fluctuation, correction of the channel amplitude-phase error is completed by adopting a dot frequency amplitude-phase error correction method or a channel equalization technology correction method, and the correction is rapid and high in precision.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation technology, and in particular to an amplitude and phase correction method for a receiving channel of a multi-antenna GNSS receiver. Background Art

[0002] The Global Satellite Navigation System (GNSS) is an air-based radio navigation and positioning system that can provide users with all-weather three-dimensional coordinates, speed and time information at any location on the Earth's surface or in near-Earth space. It includes one or more satellite constellations and their augmentation systems required to support specific tasks. The four major satellite navigation system suppliers announced by the International Committee on Global Navigation Satellite Systems include the United States' Global Positioning System GPS, Russia's GLONASS, the European Union's Galileo Satellite Navigation System (GALILEO) and China's BeiDou Satellite Navigation System (BDS).

[0003] A GNSS receiver (Global Navigation Satellite System Receiver) is an electronic device designed to receive, decode, process and utilize radio signals transmitted by the Global Navigation Satellite System (GNSS). Its core function is to accurately determine and output information such as geographic location, speed, and time by analyzing received satellite signals. A compatible GNSS receiver can simultaneously receive and process satellite signals from different systems (GPS, GLONASS, GALILEO, BDS) to achieve more stable, reliable and accurate positioning services.

[0004] Amplitude and phase correction is usually used to eliminate distortion and phase offset introduced during signal transmission. During the modulation and demodulation process, the signal may experience a variety of channel conditions, such as fading, multipath propagation, etc., which will cause the amplitude and phase of the signal to change. Through amplitude and phase correction, the original amplitude and phase of the signal can be restored as much as possible, thereby improving the performance and reliability of the communication system, improving signal quality, improving system performance and meeting specific signal processing requirements. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for amplitude and phase correction of a receiving channel of a multi-antenna GNSS receiver. According to the magnitude of the amplitude-frequency response fluctuation, a point frequency amplitude and phase error correction method or a channel equalization technology correction method is used to complete the correction of the channel amplitude and phase error. The calibration is fast and accurate.

[0006] The technical solution of the present invention is:

[0007] A method for amplitude and phase correction of a receiving channel of a multi-antenna GNSS receiver specifically comprises the following steps:

[0008] (1) Define the array signal model, take the first channel of the multi-antenna GNSS receiver as the reference channel, bring the received signal data into the array signal model, obtain the model data, and determine the amplitude and phase response fluctuations of each channel based on the array signal model and the frequency characteristics of the signals received by each channel;

[0009] (2) When the fluctuation of the amplitude-frequency response within the bandwidth is not greater than the set fluctuation threshold, the point-frequency amplitude-phase error correction method is used to complete the correction of the channel amplitude error and channel phase error;

[0010] (3) When the fluctuation of the amplitude-frequency response within the bandwidth is greater than the set fluctuation threshold, the channel equalization technology correction method is used to complete the correction of the channel amplitude error and channel phase error.

[0011] The array signal model is shown in the following formula (1):

[0012]

[0013] In formula (1), represents the model data; N(t) represents the additive Gaussian white noise received by the entire antenna array; AS(t) represents the received target signal; Γ represents the amplitude error vector, diag represents the diagonal matrix, ρ k represents the amplitude error of the kth channel signal, represents the phase error of the kth channel signal; X(t) represents the signal received by the entire antenna array of the multi-antenna GNSS receiver at time t, and the expression is shown in the following formula (2):

[0014] X(t)=AS(t)+N(t) (2);

[0015] X(t) is specifically shown in formula (3):

[0016]

[0017]

[0018] In formula (3), h ij represents the gain of the i-th array element to the j-th signal; τ ij Represents the time delay of the j-th signal reaching the i-th array element relative to the reference array element; i = 1, 2, ..., M; j = 1, 2, ..., P; ω0 is the carrier frequency, and j is an imaginary unit.

[0019] The setting fluctuation threshold includes setting amplitude error and setting phase error. The setting amplitude error is 10 of the signal amplitude. -5, set the phase error to 10 of the signal -2 .

[0020] The specific steps of using the point frequency amplitude phase error correction method to complete the channel amplitude error and channel phase error correction are:

[0021] S21. Define the number of channels of the multi-antenna GNSS receiver as N. The frequency domain complex transfer function of the kth channel is formula (4):

[0022] H k (ω)=|H k (ω)|exp[jH k (ω)] (4);

[0023] In formula (4), |H k (ω)| represents the amplitude response of the kth channel at frequency ω, that is, the change in the amplitude of the signal after passing through the kth channel; jH k (ω) represents the phase response of the kth channel at frequency ω, that is, the phase offset of the signal after passing through the kth channel; exp[jH k (ω)] is the complex representation of the phase response; the vector of the input signal received by the multi-antenna GNSS receiver is X = [X1, X2, …, X k ,…,X N ], after passing through the receiving channel, the output vector is Y=GX, and the channel transmission matrix G=diag[H1(ω),H2(ω),…,H k (ω),…,H N (ω)],H k (ω) is the frequency response of the kth channel. The first channel is used as the reference channel. The remaining channels are corrected based on the reference channel and the correction matrix C is used. The correction matrix C is shown in the following formula (5):

[0024]

[0025] After the frequency domain complex transfer function is corrected by the correction matrix, the inconsistency of amplitude and phase between channels is compensated to the reference channel;

[0026] S22. The signal source generates an electrical frequency signal whose frequency is within the working frequency band of the receiver. The signal is injected into each channel of the array element, and then the data output by each channel is sampled simultaneously. N points are sampled and a fast Fourier transform is performed. The maximum value in the output data is taken as the frequency domain representation of the signal, and then the maximum value of the frequency domain points of each channel is searched respectively. The complex number obtained by comparing the maximum value of the reference channel with the maximum value of the kth channel is the correction coefficient of the kth channel.

[0027] The specific steps of using the channel equalization technology correction method to complete the correction of channel amplitude error and channel phase error are:

[0028] S31. Define the number of channels of the multi-antenna GNSS receiver as N, select the channel with the flattest channel frequency response and the smallest distortion in the working frequency band as the reference channel, and compare the remaining channels with the reference channel to obtain a consistent frequency transfer function with good filtering characteristics;

[0029] Define the frequency response of the ith channel as C i (ω), the expected frequency response of the equalizer is E i (ω);

[0030] The frequency response of each channel after equalization is H i (ω) See the following formula (6):

[0031] H i (ω)=C i (ω)E i (ω),i=1,2,…,N (6);

[0032] Frequency response of each channel H i (ω) is equal to the frequency response H of the reference channel ref (ω), that is, H1(ω)=H2(ω)=…=H N (ω)=H ref (ω);

[0033] Therefore, the frequency response of the desired equalizer corresponding to the i-th channel is shown in the following equation (7):

[0034]

[0035] Adding a desired equalizer to all channels of the receiver makes the frequency characteristics of all channels close to the ideal state;

[0036] S32, the expected equalizer is fitted by using an FIR filter of length L, and the frequency characteristic F of the FIR filter i (ω) satisfies the following formula (8):

[0037]

[0038] In formula (8), a(ω)=[1,e -jωT ,…,e -jω(L-1)T ] T , is the phase shift vector; h i =[h i (0),h i (1),…,h i (L-1)] T, is the weight vector of the FIR filter; T is the unit time delay of the FIR filter; e -jω is the phase shift term, representing the complex phase delay of the FIR filter at frequency ω, j is the imaginary unit, ω is the angular frequency, and lT is the time delay;

[0039] S33, suppose the frequency response of the desired equalizer is E i (ω) is calculated from M discrete frequency points. After discretization, the frequency response of the expected equalizer is E i (m) See the following formula (9):

[0040]

[0041] Similarly, the frequency response of the FIR filter is discretized by equation (10):

[0042]

[0043] in, m=0,1,…,M-1;

[0044] E can be obtained by using the above formula (9): i (m), and then the least squares fitting method is used to make F i (m) Approximation to E i (m);

[0045] Since there are M errors at M discrete frequency points, the error e i Written in vector form, see the following formula (11):

[0046] e i =E i -Ah i (11);

[0047] In formula (11), e i =[e i (0),e i (1),…,e i (M-1)] T ,E i =[E i (0),E i (1),…,E i (M-1)] T ,

[0048] In formula (11), the M×L dimensional matrix A is a complex matrix of frequency factors, and the l+1th element in the m+1th row (A) m+1,l+1 The expression of is shown in the following formula (12):

[0049]

[0050] Therefore, the weight vector h of the FIR filter under the least squares method is i Satisfies the following formula (13):

[0051]

[0052] In formula (13), W = diag[W0, W1, ..., W M-1 ] is the frequency weighting matrix;

[0053] The frequency factor complex matrix A is a full-rank matrix composed of L linearly independent column vectors, which can be transformed into formula (14):

[0054] Ah i =E i (14);

[0055] Then, orthogonalize equation (14) and multiply both sides by A H , we get the L-order positive definite equation system, as shown in the following equation (15):

[0056] A H Ah i =A H E i (15);

[0057] In formula (15), A H A is a symmetric matrix, and then the Cholesky decomposition is performed to obtain the upper triangular matrix G and the lower triangular matrix G T , followed by two triangular back substitutions to obtain h i The solution is shown in the following equations (16) and (17):

[0058] GG T h i =A H E i (16);

[0059] h i =G -T G T A H E i (17);

[0060] Get the weight vector h of the FIR filter i After that, we get the expected filter frequency response E of each channel. i (ω), and the correction of the amplitude and phase of each channel signal is completed by back substitution.

[0061] Advantages of the present invention:

[0062] The present invention realizes efficient amplitude and phase correction of signals in multiple channels of a receiver by adopting point frequency amplitude and phase error correction technology and channel equalization correction technology, and the calibration is fast and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a flow chart of the present invention.

[0064] Figure 2 It is the principle diagram of the amplitude and phase error correction system.

[0065] Figure 3 It is a logic principle diagram of the FPGA of the present invention. DETAILED DESCRIPTION

[0066] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] See Figure 1 A method for amplitude and phase correction of a receiving channel of a multi-antenna GNSS receiver is provided, which specifically comprises the following steps:

[0068] (1) Define the array signal model, take the first channel of the multi-antenna GNSS receiver as the reference channel, bring the received signal data into the array signal model, obtain the model data, and determine the amplitude and phase response fluctuations of each channel based on the array signal model and the frequency characteristics of the signals received by each channel;

[0069] The array signal model is shown in the following formula (1):

[0070]

[0071] In formula (1), represents the model data; N(t) represents the additive Gaussian white noise received by the entire antenna array; AS(t) represents the received target signal; Γ represents the amplitude error vector, diag represents the diagonal matrix, ρ k represents the amplitude error of the kth channel signal, represents the phase error of the kth channel signal; X(t) represents the signal received by the entire antenna array of the multi-antenna GNSS receiver at time t, and the expression is shown in the following formula (2):

[0072] X(t)=AS(t)+N(t) (2);

[0073] X(t) is specifically shown in formula (3):

[0074]

[0075] In formula (3), h ij represents the gain of the i-th array element to the j-th signal; τ ij represents the time delay of the jth signal reaching the ith array element relative to the reference array element; i = 1, 2, ..., M; j = 1, 2, ..., P; ω0 is the carrier frequency, j is the imaginary unit;

[0076] (2) When the fluctuation of the amplitude-frequency response within the bandwidth is not greater than the set fluctuation threshold, the point frequency amplitude-phase error correction method is used to complete the correction of the channel amplitude error and the channel phase error; wherein the set fluctuation threshold includes the set amplitude error and the set phase error, and the set amplitude error is 10 of the signal amplitude. -5 , set the phase error to 10 of the signal -2 ;

[0077] The specific steps of using the point frequency amplitude phase error correction method to complete the channel amplitude error and channel phase error correction are as follows:

[0078] S21. Define the number of channels of the multi-antenna GNSS receiver as N. The frequency domain complex transfer function of the kth channel is formula (4):

[0079] H k (ω)=|H k (ω)|exp[jH k (ω)] (4);

[0080] In formula (4), |H k (ω)| represents the amplitude response of the kth channel at frequency ω, that is, the change in the amplitude of the signal after passing through the kth channel; jH k (ω) represents the phase response of the kth channel at frequency ω, that is, the phase offset of the signal after passing through the kth channel; exp[jH k (ω)] is the complex representation of the phase response; the vector of the input signal received by the multi-antenna GNSS receiver is X = [X1, X2, …, X k ,…,X N ], after passing through the receiving channel, the output vector is Y=GX, and the channel transmission matrix G=diag[H1(ω),H2(ω),…,H k (ω),…,H N (ω)],H k (ω) is the frequency response of the kth channel. The first channel is used as the reference channel. The remaining channels are corrected based on the reference channel and the correction matrix C is used. The correction matrix C is shown in the following formula (5):

[0081]

[0082] After the frequency domain complex transfer function is corrected by the correction matrix, the inconsistency of amplitude and phase between channels is compensated to the reference channel;

[0083] S22, the signal source generates an electric frequency signal whose frequency is within the working frequency band of the receiver. The signal is injected into each channel of the array element, and then the data output by each channel is sampled simultaneously, N points are sampled, and a fast Fourier transform is performed. Then, the maximum value in the output data is taken as the frequency domain representation of the signal, and then the maximum value of the frequency domain points of each channel is searched respectively. The complex number obtained by comparing the maximum value of the reference channel with the maximum value of the kth channel is the correction coefficient of the kth channel;

[0084] (3) When the fluctuation of the amplitude-frequency response within the bandwidth is greater than the set fluctuation threshold, the channel equalization technology correction method is used to complete the correction of the channel amplitude error and channel phase error;

[0085] The specific steps of using the channel equalization technology correction method to complete the correction of channel amplitude error and channel phase error are:

[0086] S31. Define the number of channels of the multi-antenna GNSS receiver as N, select the channel with the flattest channel frequency response and the smallest distortion in the working frequency band as the reference channel, and compare the remaining channels with the reference channel to obtain a consistent frequency transfer function with good filtering characteristics;

[0087] Define the frequency response of the ith channel as C i (ω), the expected frequency response of the equalizer is E i (ω);

[0088] The frequency response of each channel after equalization is H i (ω) See the following formula (6):

[0089] H i (ω)=C i (ω)E i (ω),i=1,2,…,N (6);

[0090] Frequency response of each channel H i (ω) is equal to the frequency response H of the reference channel ref (ω), that is, H1(ω)=H2(ω)=…=H N (ω)=H ref (ω);

[0091] Therefore, the frequency response of the desired equalizer corresponding to the i-th channel is shown in the following equation (7):

[0092]

[0093] Adding a desired equalizer to all channels of the receiver makes the frequency characteristics of all channels close to the ideal state;

[0094] S32, the expected equalizer is fitted by using an FIR filter of length L, and the frequency characteristic F of the FIR filter i (ω) satisfies the following formula (8):

[0095]

[0096] In formula (8), a(ω)=[1,e -jωT ,…,e -jω(L-1)T ] T , is the phase shift vector; h i =[h i (0),h i (1),…,h i (L-1)] T , is the weight vector of the FIR filter; T is the unit time delay of the FIR filter; e -jωlT is the phase shift term, representing the complex phase delay of the FIR filter at frequency ω, j is the imaginary unit, ω is the angular frequency, and lT is the time delay;

[0097] S33, suppose the frequency response of the desired equalizer is E i (ω) is calculated from M discrete frequency points. After discretization, the frequency response of the expected equalizer is E i (m) See the following formula (9):

[0098]

[0099] Similarly, the frequency response of the FIR filter is discretized by equation (10):

[0100]

[0101] in, m=0,1,…,M-1;

[0102] E can be obtained by using the above formula (9): i (m), and then the least squares fitting method is used to make F i (m) Approximation to E i (m);

[0103] Since there are M errors at M discrete frequency points, the error e i Written in vector form, see the following formula (11):

[0104] e i =E i -Ah i(11);

[0105] In formula (11), e i =[e i (0),e i (1),…,e i (M-1)] T ,E i =[E i (0),E i (1),…,E i (M-1)] T ,

[0106] In formula (11), the M×L dimensional matrix A is a complex matrix of frequency factors, and the l+1th element in the m+1th row (A) m+1,l+1 The expression of is shown in the following formula (12):

[0107]

[0108] Therefore, the weight vector h of the FIR filter under the least squares method is i Satisfies the following formula (13):

[0109]

[0110] In formula (13), W = diag[W0, W1, ..., W M-1 ] is the frequency weighting matrix;

[0111] The frequency factor complex matrix A is a full-rank matrix composed of L linearly independent column vectors, which can be transformed into formula (14):

[0112] Ah i =E i (14);

[0113] Then, orthogonalize equation (14) and multiply both sides by A H , we get the L-order positive definite equation system, as shown in the following equation (15):

[0114] A H Ah i =A H E i (15);

[0115] In formula (15), A H A is a symmetric matrix, and then the Cholesky decomposition is performed to obtain the upper triangular matrix G and the lower triangular matrix G T , followed by two triangular back substitutions to obtain h i The solution is shown in the following equations (16) and (17):

[0116] GGT h i =A H E i (16);

[0117] h i =G -T G T A H E i (17);

[0118] Get the weight vector h of the FIR filter i After that, we get the expected filter frequency response E of each channel. i (ω), back substitution completes the correction of the amplitude and phase of each channel signal;

[0119] (4) According to the channel amplitude and phase correction method, complete the hardware design and implementation of the amplitude and phase error correction system;

[0120] See Figure 2 The intermediate frequency analog signal is first converted into a digital signal by the A / D conversion chip AD6644 (AD1-AD8), and then transmitted to the FPGA chip for orthogonal difference, digital down conversion (DDC), and FIR filtering, and finally a baseband I / Q orthogonal complex signal is obtained; wherein, the amplitude and phase error correction function is completed by the FPGA and DSP. The FPGA (field programmable gate array) pre-processes the data and controls the timing of the amplitude and phase correction system. The DSP chip uses the uncorrected channel data provided by the FPGA and the amplitude and phase error correction algorithm to obtain the amplitude and phase correction coefficients, and writes these coefficients into the FPGA and the storage chip FLASH respectively. The FLASH chip is used to store the amplitude and phase correction coefficients of each channel. CLK refers to the clock signal. J1 is a connector socket on the signal processing board, which is mainly used to provide power input. J3, J4 and J5 are communication interfaces on the signal processing board, which are used to transmit the orthogonal complex signal output by the signal processing board to the back-end signal processing system, and are also used to transmit the communication control protocol signals between the amplitude and phase error correction system and other subsystems.

[0121] See Figure 3, the processing process of FPGA is as follows: the data preprocessing module is responsible for orthogonally down-converting the intermediate frequency digital data after AD conversion to obtain the corresponding I / Q raw data, and weighting these complex signals according to the received control command. When correction is required, the weight coefficient is set to 1; when working normally, the weight coefficient is set to the correction complex coefficient of each channel. The serial communication module of the signal processing board uses the SPI protocol to receive and parse the serial commands of the signal processing board, and return the channel correction coefficient. At the same time, it schedules the work of other modules according to the received commands. The DSP bus communication module transmits the raw data of the I / Q data of each channel to the DSP for the calculation of the amplitude and phase correction weight coefficient, and transmits the correction coefficient calculated by the DSP to the data preprocessing module. The LVDS parallel-to-serial conversion module is responsible for converting the I / Q two-way parallel data (corrected I / Q data) after amplitude and phase error correction into serial data, and then transmits it to the signal processing board in the form of LVDS through the high-speed backplane. On the signal processing board, MUSIC high-resolution direction finding and adaptive beamforming functions are finally realized.

[0122] The processing process of the DSP chip is as follows: the DSP receives the correction command and channel data, and calculates the correction coefficient. Subsequently, the correction coefficient of each channel is written into the FLASH, and then written from the FLASH into the RAM inside the FPGA, and finally a handshake signal is sent to the FPGA to confirm the completion; after entering the correction state, the FPGA synchronously writes the I / Q data of each channel into the FIFO inside the FPGA. After the data is written, the FPGA sends an interrupt to the DSP to notify the completion of the data transmission. After receiving the interrupt, the DSP first reads other control commands, such as the frequency code and whether the weight coefficient needs to be written into the FLASH. Then, with the first channel as the reference channel, the data in the FIFO is subjected to a fast Fourier transform (FFT), and the amplitude and phase correction coefficient of each channel is obtained by comparing the ratio of the peak value of the FFT of each channel with the peak value of the standard channel. Finally, the amplitude and phase correction coefficient of each channel is written into the corresponding position of the RAM inside the FPGA, and the DSP sends a response signal to the FPGA through the flag signal, and at the same time exits the correction state and enters the state of waiting for the FPGA correction interrupt command.

[0123] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for amplitude and phase correction of a receiving channel of a multi-antenna GNSS receiver, characterized in that: The specific steps include: (1) Define the array signal model, take the first channel of the multi-antenna GNSS receiver as the reference channel, bring the received signal data into the array signal model, obtain the model data, and determine the amplitude and phase response fluctuations of each channel based on the array signal model and the frequency characteristics of the signals received by each channel; (2) When the fluctuation of the amplitude-frequency response within the bandwidth is not greater than the set fluctuation threshold, the point-frequency amplitude-phase error correction method is used to complete the correction of the channel amplitude error and channel phase error; (3) When the fluctuation of the amplitude-frequency response within the bandwidth is greater than the set fluctuation threshold, the channel equalization technology correction method is used to complete the correction of the channel amplitude error and channel phase error.

2. The method for amplitude and phase correction of a receiving channel of a multi-antenna GNSS receiver according to claim 1, characterized in that: The array signal model is shown in the following formula (1): In formula (1), represents the model data; N(t) represents the additive Gaussian white noise received by the entire antenna array; AS(t) represents the received target signal; Γ represents the amplitude error vector, diag represents the diagonal matrix, ρ k represents the amplitude error of the kth channel signal, represents the phase error of the kth channel signal; X(t) represents the signal received by the entire antenna array of the multi-antenna GNSS receiver at time t, and the expression is shown in the following formula (2): X(t)=AS(t)+N(t) (2); X(t) is specifically shown in formula (3): In formula (3), h ij represents the gain of the i-th array element to the j-th signal; τ ij Represents the time delay of the j-th signal reaching the i-th array element relative to the reference array element; i = 1, 2, ..., M; j = 1, 2, ..., P; ω0 is the carrier frequency, and j is an imaginary unit.

3. The method for amplitude and phase correction of a receiving channel of a multi-antenna GNSS receiver according to claim 1, characterized in that: The setting fluctuation threshold includes setting amplitude error and setting phase error. The setting amplitude error is 10 of the signal amplitude. -5 , set the phase error to 10 of the signal -2 .

4. The method for amplitude and phase correction of a receiving channel of a multi-antenna GNSS receiver according to claim 1, characterized in that: The specific steps of using the point frequency amplitude phase error correction method to complete the channel amplitude error and channel phase error correction are: S21. Define the number of channels of the multi-antenna GNSS receiver as N. The frequency domain complex transfer function of the kth channel is formula (4): H k (ω)=|H k (ω)|exp[jH k (ω)] (4); In formula (4), |H k (ω)| represents the amplitude response of the kth channel at frequency ω, that is, the change in the amplitude of the signal after passing through the kth channel; jH k (ω) represents the phase response of the kth channel at frequency ω, that is, the phase offset of the signal after passing through the kth channel; exp[jH k (ω)] is the complex representation of the phase response; The vector of the input signal received by the multi-antenna GNSS receiver is X = [X1, X2, ..., X k ,…,X N ], after passing through the receiving channel, the output vector is Y=GX, and the channel transmission matrix G=diag[H1(ω),H2(ω),…,H k (ω),…,H N (ω)],H k (ω) is the frequency response of the kth channel. The first channel is used as the reference channel. The remaining channels are corrected based on the reference channel and the correction matrix C is used. The correction matrix C is shown in the following formula (5): After the frequency domain complex transfer function is corrected by the correction matrix, the inconsistency of amplitude and phase between channels is compensated to the reference channel; S22. The signal source generates an electrical frequency signal whose frequency is within the working frequency band of the receiver. The signal is injected into each channel of the array element, and then the data output by each channel is sampled simultaneously. N points are sampled and a fast Fourier transform is performed. The maximum value in the output data is taken as the frequency domain representation of the signal, and then the maximum value of the frequency domain points of each channel is searched respectively. The complex number obtained by comparing the maximum value of the reference channel with the maximum value of the kth channel is the correction coefficient of the kth channel.

5. The method for amplitude and phase correction of a receiving channel of a multi-antenna GNSS receiver according to claim 1, characterized in that: The specific steps of using the channel equalization technology correction method to complete the correction of channel amplitude error and channel phase error are: S31. Define the number of channels of the multi-antenna GNSS receiver as N, select the channel with the flattest channel frequency response and the smallest distortion in the working frequency band as the reference channel, and compare the remaining channels with the reference channel to obtain a consistent frequency transfer function with good filtering characteristics; Define the frequency response of the ith channel as C i (ω), the expected frequency response of the equalizer is E i (ω); The frequency response of each channel after equalization is H i (ω) See the following formula (6): H i (ω)=C i (ω)E i (ω),i=1,2,…,N (6); Frequency response of each channel H i (ω) is equal to the frequency response H of the reference channel ref (ω), that is, H1(ω)=H2(ω)=…=H N (ω)=H ref (ω); Therefore, the frequency response of the desired equalizer corresponding to the i-th channel is shown in the following equation (7): Adding a desired equalizer to all channels of the receiver makes the frequency characteristics of all channels close to the ideal state; S32, the expected equalizer is fitted by using an FIR filter of length L, and the frequency characteristic F of the FIR filter i (ω) satisfies the following formula (8): In formula (8), a(ω)=[1,e -jωT ,…,e -jω(L-1)T ] T , is the phase shift vector; h i =[h i (0),h i (1),…,h i (L-1)] T , is the weight vector of the FIR filter; T is the unit time delay of the FIR filter; e -jωlT is the phase shift term, representing the complex phase delay of the FIR filter at frequency ω, j is the imaginary unit, ω is the angular frequency, and lT is the time delay; S33, suppose the frequency response of the desired equalizer is E i (ω) is calculated from M discrete frequency points. After discretization, the frequency response of the expected equalizer is E i (m) See the following formula (9): Similarly, the frequency response of the FIR filter is discretized by equation (10): in, E can be obtained by using the above formula (9): i (m), and then the least squares fitting method is used to make F i (m) Approximation to E i (m); Since there are M errors at M discrete frequency points, the error e i Written in vector form, see the following formula (11): And i =And i -Oh i (11); In formula (11), e i =[e i (0),e i (1),…,e i (M-1)] T ,E i = [E i (0), E i (1),…,E i (M-1)] T , In formula (11), the M×L dimensional matrix A is a complex matrix of frequency factors, and the l+1th element in the m+1th row (A) m+1,l+1 The expression of is shown in the following formula (12): Therefore, the weight vector h of the FIR filter under the least squares method is i Satisfies the following formula (13): In formula (13), W = diag[W0, W1, ..., W M-1 ] is the frequency weighting matrix; The frequency factor complex matrix A is a full-rank matrix composed of L linearly independent column vectors, which can be transformed into formula (14): Oh i =And i (14); Then, orthogonalize equation (14) and multiply both sides by A H , we get the L-order positive definite equation system, as shown in the following equation (15): TO H Oh i =A H AND i (15); In formula (15), A H A is a symmetric matrix, and then the Cholesky decomposition is performed to obtain the upper triangular matrix G and the lower triangular matrix G T , followed by two triangular back substitutions to obtain h i The solution is shown in the following equations (16) and (17): GG T h i =A H E i (16); h i =G -T G T A H E i (17); Get the weight vector h of the FIR filter i After that, we get the expected filter frequency response E of each channel. i (ω), and the correction of the amplitude and phase of each channel signal is completed by back substitution.

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