Near-field calibration method based on near-field antenna offset error estimation

Abstract

The invention relates to the technical field of signal calibration, in particular to a near-field calibration method based on near-field antenna offset error estimation, and the method comprises the steps: carrying out the near-field calibration of a target phased-array antenna, obtaining the phase value of each channel, comparing the phase value with near-field reference data, and obtaining the original calibration value of each channel; wherein the number of the target phased-array antennas is M rows and N columns; dividing the original calibration value of each channel into M sections according to rows, respectively performing phase unwrapping operation on each section to obtain M phase vectors, respectively performing linear fitting on each phase vector, and estimating a slope value corresponding to each row; based on the slope value corresponding to each row, matching a corresponding offset in an offset error slope corresponding table, and calculating to obtain an estimated offset according to each offset; respectively calculating the phase difference of each channel caused by the estimated offset, and compensating the original calibration value based on the phase difference to obtain a compensated calibration value; and correcting the calibration coefficient based on the compensated calibration value.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of signal calibration technology, and in particular to a near-field calibration method based on near-field antenna offset error estimation. Background Art

[0002] Phased array antennas adjust the needle beam pointing and radiation pattern of the array antenna in real time by controlling the phase shift of each channel. The beam formed by it has the advantages of high pointing accuracy, fast scanning speed and adjustable beam shape, and is widely used in radar and communication technology. However, due to factors such as device characteristics and manufacturing and assembly errors, technicians cannot completely ensure that each antenna channel has completely consistent or known amplitude and phase characteristics through circuit design. Therefore, during the radar joint debugging test, the antenna array surface needs to be calibrated for amplitude and phase. The accuracy of the calibration coefficient will greatly affect the radiation characteristics of the radar.

[0003] The far-field calibration method meets the far-field conditions of the antenna, can measure the initial amplitude and phase values ​​of each antenna channel more accurately, and has a high error tolerance. However, due to the limitations of the far-field conditions and site constraints, when the use environment changes greatly, it is impossible to constantly collect changes in the antenna array through the far-field calibration method. Therefore, in daily use, the calibration coefficient can be corrected at all times through the near-field calibration method. The near-field calibration method places a calibration antenna at a fixed point at the front end of the antenna array. The antenna is used to receive the transmit calibration signal of each channel of the antenna array or radiate the calibration signal to the antenna array to achieve the transmit and receive calibration of each channel of the antenna array. The near-field calibration method does not need to meet the far-field conditions, but only needs to measure the relative position of the near-field calibration antenna relative to the antenna array to be measured, so it is more convenient and quicker.

[0004] The near-field calibration antenna is close to the antenna array, and the position offset error has a greater impact on the phase of each antenna channel. Therefore, in actual use, the position accuracy requirements for the near-field calibration antenna are higher, especially for high-frequency band antennas. The distance accuracy requirements for the near-field calibration antenna are more stringent and difficult to guarantee, which will lead to a large error in the near-field calibration coefficient and seriously affect the radar measurement accuracy. Summary of the invention

[0005] In order to solve the above technical problems, an embodiment of the present application proposes a near-field calibration method based on near-field antenna offset error estimation. By measuring the phase information of the near-field calibration data, the offset of the near-field calibration antenna is estimated in real time, and phase compensation is performed on all antenna channels based on the offset. This avoids measurement errors caused by the offset of the near-field calibration antenna during the near-field calibration process for high-frequency band radars, thereby improving the calibration compensation accuracy.

[0006] In order to achieve the above-mentioned purpose, an embodiment of the present application proposes a near-field calibration method based on near-field antenna offset error estimation, the method comprising: using a near-field test antenna to perform near-field calibration on a target phased array antenna, obtaining a phase value of each channel of the target phased array antenna in a current state, and comparing the phase value of each channel with pre-acquired near-field reference data to obtain an original calibration value of each channel; wherein the target phased array antenna has M rows and N columns, with a total of M×N channels; dividing the original calibration value of each channel into M segments by row, performing phase unwrapping operations on each segment respectively, obtaining M phase vectors, and performing linear fitting on each phase vector respectively, estimating the slope value corresponding to each row; based on the slope value corresponding to each row, matching in a pre-constructed offset error slope corresponding table, matching the closest error slope for each row, returning the corresponding offset, and calculating an estimated offset based on each offset; calculating the phase difference caused by the estimated offset for each channel respectively, and compensating the original calibration value based on the calculated phase difference to obtain a compensated calibration value; and correcting the calibration coefficient based on the compensated calibration value.

[0007] In order to achieve the above-mentioned purpose, an embodiment of the present application also proposes a near-field calibration system based on near-field antenna offset error estimation, the system comprising: a near-field test antenna, a table building module, an original calibration module, an unwinding and linear fitting module, a table lookup matching module, a compensation module and a calibration coefficient correction module; the table building module is used to construct an offset error slope correspondence table; the original calibration module is used to perform near-field calibration on the target phased array antenna using the near-field test antenna, obtain the phase value of each channel of the target phased array antenna in the current state, and compare the phase value of each channel with the pre-acquired near-field reference data to obtain the original calibration value of each channel, wherein the target phased array antenna has M rows and N columns, with a total of M×N channels; the unwinding and linear fitting module A block is used to divide the original calibration value of each channel into M segments by row, perform phase unwrapping operation on each segment to obtain M phase vectors, and perform linear fitting on each phase vector to estimate the slope value corresponding to each row; a table lookup matching module is used to match in a pre-built offset error slope corresponding table based on the slope value corresponding to each row, match the closest error slope for each row, return the corresponding offset, and calculate the estimated offset based on each offset; a compensation module is used to calculate the phase difference of each channel caused by the estimated offset, and compensate the original calibration value based on the calculated phase difference to obtain the compensated calibration value; a calibration coefficient correction module is used to correct the calibration coefficient based on the compensated calibration value.

[0008] In order to achieve the above-mentioned purpose, an embodiment of the present application also proposes an electronic device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute a near-field calibration method based on near-field antenna offset error estimation as described above.

[0009] In order to achieve the above objectives, an embodiment of the present application further proposes a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it can implement a near-field calibration method based on near-field antenna offset error estimation as described above.

[0010] The embodiment of the present application proposes a near-field calibration method based on near-field antenna offset error estimation, which adds offset estimation and offset phase compensation processes on the basis of the original near-field calibration process. The offset of the near-field calibration antenna moving along the pitch dimension is small and can be ignored, but the offset of the azimuth dimension is large. When the near-field calibration antenna has an azimuth dimension offset, the phase of the original calibration value of each channel of the near-field calibration antenna will have certain characteristics, and such characteristics are reflected in the slope. Therefore, by dividing the original calibration value of each channel into M segments by row, performing phase unwrapping operations on each segment respectively, obtaining M phase vectors, and performing linear fitting on each phase vector respectively, the slope value corresponding to each row can be estimated, and then based on the slope value corresponding to each row, matching is performed in the pre-constructed offset error slope corresponding table, matching the closest error slope for each row, returning the corresponding offset, and the estimated offset can be calculated. Finally, the phase difference caused by the estimated offset of each channel is calculated respectively, and the original calibration value is compensated based on the calculated phase difference to obtain the compensated calibration value, and the calibration coefficient is corrected based on the compensated calibration value. The measurement error of the high-frequency radar caused by the offset of the near-field calibration antenna during the near-field calibration process is avoided, and the calibration compensation accuracy is improved.

[0011] Optionally, the target phased array antenna has 4 rows and N columns, with a total of 4N channels, and the original calibration value of each channel is divided into M segments by row, and a phase unwrapping operation is performed on each segment to obtain M phase vectors, and linear fitting is performed on each phase vector to estimate the slope value corresponding to each row, including: dividing the original calibration value of each channel into four segments {[1:N], [N+1:2N], [2N+1:3N], [3N+1:4N]} by row, which are respectively recorded as L1, L2, L3 and L4; performing a phase unwrapping operation on each segment of data to obtain a phase vector corresponding to each row, which are respectively recorded as Φ1, Φ2, Φ3 and Φ4, wherein the phase unwrapping operation is specifically to expand L mThe radian phase angle in m = 1, 2, 3, 4. Whenever the jump between consecutive radian phase angles is greater than or equal to π, the phase angle is shifted by increasing integer multiples of ±2π until the jump between consecutive radian phase angles is less than π. Linear fitting is performed on the phase vector corresponding to each row, and the slope value corresponding to each row is estimated, which are recorded as k1, k2, k3 and k4 respectively.

[0012] Optionally, the offset error slope correspondence table is constructed by the following steps: establishing a near-field test geometric model according to the geometric positions of each channel of the target phased array antenna and the relative position coordinates of the near-field test antenna; simulating different degrees of offset of the near-field test antenna in the directional dimension, and establishing an offset error slope correspondence table T based on the near-field test geometric model. m {[d mn ,K mn ]}, m=1,2,3,4, n=1,2,…,N; where T m The offset error slope correspondence table of the mth row, d mn Indicates the nth offset of the mth row, K mn For mn The corresponding error slope.

[0013] Optionally, after linear fitting is performed on each phase vector to estimate the slope value corresponding to each row, before matching is performed in a pre-constructed offset error slope corresponding table based on the slope value corresponding to each row, the method further includes: calculating the slope mean of the slope value corresponding to each row. And calculate the slope variance S of the slope values ​​corresponding to each row 2 , Determine the slope variance S 2 Is it greater than the preset variance threshold? If the slope variance S 2 Greater than variance threshold Then use the original calibration value directly to correct the calibration coefficient; if the slope variance S 2 Less than or equal to the variance threshold Based on the slope values ​​corresponding to each row, a match is made in the pre-built offset error slope correspondence table. The setting of the slope consistency judgment process effectively saves computing resources, does not perform compensation when the offset is small, and takes into account the speed and accuracy of near-field calibration.

[0014] Optionally, based on the slope value corresponding to each row, a match is performed in a pre-built offset error slope correspondence table, the closest error slope is matched for each row, and the corresponding offset is returned, including:

[0015] From the offset error slope corresponding tables T1, T2, T3, and T4, respectively, match the error slope K closest to k1, k2, k3, and k4.1min , K 2min , K 3min , K 4min , and return the corresponding offsets d1, d2, d3, d4;

[0016] The table lookup matching process is implemented by the following formula:

[0017] K 1min =min i {abs(k1-K 1i )};

[0018] K 2min =min j {abs(k2-K 2j )};

[0019] K 3min =min p {abs(k3-K 3p )};

[0020] K 4min =min q {abs(k4-K 4q )};

[0021] Where abs(·) means to find the absolute value, K 1i represents the i-th error slope in T1, K 2j represents the jth error slope in T2, K 3p represents the pth error slope in T3, K 4q represents the qth error slope in T4;

[0022] The estimated offset is calculated based on each offset and is implemented using the following formula:

[0023]

[0024] in, is the calculated estimated offset.

[0025] Optionally, the phase difference of each channel due to the estimated offset is calculated separately, including:

[0026] The center of the target phased array antenna is taken as the coordinate origin, the X coordinate is the vertical direction of the array plane, the Y coordinate is the horizontal direction, and the Z coordinate is the elevation direction. It is assumed that the near-field calibration antenna is directly above the center of the array.

[0027] Assume that the initial position coordinates of the near-field calibration antenna are (X0,0,0) and the position coordinates of the bth channel are (x b ,y b ,z b), the phase difference of each channel due to the estimated offset is calculated by the following formula:

[0028]

[0029] Where b = 1, 2, ..., 4N, λ is the preset adjustment parameter, represents the phase difference of the bth channel due to the estimated offset;

[0030] The original calibration value is compensated based on the calculated phase difference to obtain the compensated calibration value, which is achieved by the following formula:

[0031]

[0032] in, is the original calibration value of the bth channel, is the calibration value after compensation of the bth channel.

[0033] Optionally, the near-field reference data is obtained by synchronously measuring near-field data when performing far-field calibration on the target phased array antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the related technologies, the drawings required for use in the embodiments of the present application or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 is a flowchart of a near-field calibration method based on near-field antenna offset error estimation provided in one embodiment of the present application;

[0036] Figure 2 is a schematic diagram of a near-field calibration scenario provided in an embodiment of the present application;

[0037] Figure 3 It is a schematic diagram of the phase characteristics of each channel of the target phased array antenna when the near-field calibration antenna provided in an embodiment of the present application is offset in the azimuth dimension;

[0038] Figure 4 is a schematic diagram of the corresponding relationship between the azimuth dimension offset and the slope provided in an embodiment of the present application;

[0039] Figure 5 is a schematic diagram of an azimuth offset estimation process provided in one embodiment of the present application;

[0040] Figure 6is a structural schematic diagram of a near-field calibration system based on near-field antenna offset error estimation provided in another embodiment of the present application;

[0041] Figure 7 It is a structural schematic diagram of an electronic device provided in another embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. In the various embodiments of the present application, many technical details are proposed in order to make the reader better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is only for the convenience of description, and the specific implementation mode of the present application should not constitute any limitation. The various embodiments can be combined with each other and referenced to each other under the premise of no contradiction.

[0043] An embodiment of the present application proposes a near-field calibration method based on near-field antenna offset error estimation, which is applied to an electronic device, wherein the electronic device can be a terminal or a server. In this embodiment and the following embodiments, the electronic device is described using the server as an example. The implementation details of the near-field calibration method based on near-field antenna offset error estimation proposed in this embodiment are specifically described below. The following content is only the implementation details provided for ease of understanding and is not necessary for the implementation of this solution.

[0044] The specific process of the near-field calibration method based on near-field antenna offset error estimation proposed in this embodiment can be as follows: Figure 1 As shown, including:

[0045] Step 101, perform near-field calibration on the target phased array antenna using a near-field test antenna, obtain the phase value of each channel of the target phased array antenna in the current state, and compare the phase value of each channel with the pre-acquired near-field reference data to obtain the original calibration value of each channel, wherein the target phased array antenna has M rows and N columns, with a total of M×N channels.

[0046] In the specific implementation, the scenario and basic process of near-field calibration are similar to those of traditional near-field calibration. Figure 2As shown. The server first uses the near-field test antenna to perform near-field calibration on the target phased array antenna to obtain the phase value of each channel of the target phased array antenna in the current state (in fact, the amplitude value and phase value are returned at the same time, but the offset of the near-field calibration antenna along the pitch dimension is very small, so the amplitude value is not compensated). The phase value of each channel is then compared with the pre-acquired near-field reference data to obtain the original calibration value of each channel. The near-field reference data is obtained by synchronously measuring the near-field data when the target phased array antenna is far-field calibrated. It is worth noting that the target phased array antenna has M rows and N columns, with a total of M×N channels.

[0047] Step 102, divide the original calibration value of each channel into M segments by row, perform phase unwrapping operation on each segment to obtain M phase vectors, and perform linear fitting on each phase vector to estimate the slope value corresponding to each row.

[0048] In the specific implementation, the server divides the original calibration value of each channel into M segments by row. Considering that the original calibration value may have phase wrapping, it is necessary to perform phase unwrapping operation on each segment separately to obtain M phase vectors. Then, linear fitting is performed on each phase vector separately to estimate the slope value corresponding to each row.

[0049] In one example, the target phased array antenna has 4 rows and N columns, with a total of 4N channels. The server divides the original calibration values ​​of each channel into four segments {[1:N], [N+1:2N], [2N+1:3N], [3N+1:4N]} by row, which are recorded as L1, L2, L3 and L4 respectively. Then, the phase unwrapping operation is performed on each segment of data to obtain the phase vector corresponding to each row, which are recorded as Φ1, Φ2, Φ3 and Φ4 respectively. Finally, the phase vector corresponding to each row is linearly fitted to calculate the slope value corresponding to each row, which are recorded as k1, k2, k3 and k4 respectively.

[0050] In an example, for any piece of data L m , m=1,2,3,4, the phase unwrapping operation is as follows: expand L m Whenever the jump between consecutive radian phase angles is greater than or equal to π, the phase angle is shifted by increasing the integer multiple of ±2π until the jump between consecutive radian phase angles is less than π, thus obtaining the same phase angle as L m The corresponding unwrapped phase vector Φ m .

[0051] In one example, when the near-field calibration antenna is offset in azimuth, the phase characteristics of each channel of the target phased array antenna are as follows: Figure 3 As shown in the figure, the corresponding relationship between the azimuth offset and the slope can be expressed as Figure 4 As shown, from Figure 3 and Figure 4 It can be seen that the phase characteristics can be well reflected in the slope.

[0052] Step 103, based on the slope value corresponding to each row, matching is performed in a pre-constructed offset error slope corresponding table, the closest error slope is matched for each row, the corresponding offset is returned, and an estimated offset is calculated based on each offset.

[0053] In the specific implementation, after fitting the slope values ​​corresponding to each row, the server can match the pre-built offset error slope corresponding table based on the slope values ​​corresponding to each row, match the closest error slope for each row, return the corresponding offset, and calculate the estimated offset based on each offset. The setting of the slope consistency judgment process effectively saves computing resources, does not compensate when the offset is small, and takes into account both calibration speed and accuracy.

[0054] In an example, Figure 5 As shown, before performing table lookup matching, the server needs to perform slope consistency judgment to determine whether compensation is required. The server calculates the slope mean of the slope values ​​corresponding to each row And calculate the slope variance S of the slope values ​​corresponding to each row 2 , Then determine the slope variance S 2 Is it greater than the preset variance threshold? If the slope variance S 2 Greater than variance threshold The original calibration value is directly used to correct the calibration coefficient without compensation. If the slope variance S 2 Less than or equal to the variance threshold It is necessary to match the slope values ​​corresponding to each row in the pre-built offset error slope corresponding table for compensation.

[0055] In one example, the server needs to pre-build the offset error slope correspondence table. First, according to the geometric positions of each channel of the target phased array antenna and the relative position coordinates of the near-field test antenna, a near-field test geometric model is established. Next, different degrees of offset of the near-field test antenna in the directional dimension are simulated. Based on the near-field test geometric model, an offset error slope correspondence table T is established. m {[d mn ,K mn ]}, m = 1, 2, 3, 4, n = 1, 2, ..., N, where T m The offset error slope correspondence table of the mth row, d mn Indicates the nth offset of the mth row, K mn For mn The corresponding error slope.

[0056] In one example, when the server performs table lookup matching, it looks up the error slope K closest to k1, k2, k3, and k4 from the offset error slope corresponding tables T1, T2, T3, and T4 respectively. 1min , K 2min , K 3min , K 4min , and returns the corresponding offsets d1, d2, d3, and d4.

[0057] In one example, the table lookup matching process is implemented by the following formula:

[0058] K 1min =min i {abs(k1-K 1i )};

[0059] K 2min =min j {abs(k2-K 2j )};

[0060] K 3min =min p {abs(k3-K 3p )};

[0061] K 4min =min q {abs(k4-K 4q )};

[0062] Where abs(·) means to find the absolute value, K 1i represents the i-th error slope in T1, K 2j represents the jth error slope in T2, K 3p represents the pth error slope in T3, K 4q represents the qth error slope in T4.

[0063] In one example, the server calculates the estimated offset based on each offset, which is implemented by the following formula:

[0064]

[0065] in, is the calculated estimated offset.

[0066] Step 104 , respectively calculating the phase difference of each channel caused by the estimated offset, and compensating the original calibration value based on the calculated phase difference to obtain a compensated calibration value.

[0067] In a specific implementation, after calculating the estimated offset, the server needs to calculate the phase difference of each channel caused by the estimated offset, and compensate the original calibration value based on the calculated phase difference to obtain the compensated calibration value.

[0068] In one example, the server uses the center of the target phased array antenna as the origin of the coordinates, the X coordinate is the vertical direction of the array plane, the Y coordinate is the horizontal direction, and the Z coordinate is the elevation direction. It is assumed that the near-field calibration antenna is directly above the center of the array. Assume that the initial position coordinates of the near-field calibration antenna are (X0,0,0), and the position coordinates of the bth channel are (x b ,y b ,z b ), the phase difference of each channel due to the estimated offset is calculated by the following formula:

[0069]

[0070] Where b = 1, 2, ..., 4N, λ is the preset adjustment parameter, It represents the phase difference of the bth channel due to the estimated offset.

[0071] In one example, the server compensates the original calibration value based on the calculated phase difference to obtain a compensated calibration value, which is implemented by the following formula:

[0072]

[0073] in, is the original calibration value of the bth channel, is the calibration value after compensation of the bth channel.

[0074] Step 105, correcting the calibration coefficient based on the compensated calibration value.

[0075] In a specific implementation, after obtaining the compensated calibration value, the server can correct the calibration coefficient based on the compensated calibration value to achieve high-precision near-field calibration.

[0076] The present embodiment proposes a near-field calibration method based on near-field antenna offset error estimation, which adds an offset estimation and offset phase compensation process on the basis of the original near-field calibration process. The offset of the near-field calibration antenna moving along the pitch dimension is small and can be ignored, but the offset of the azimuth dimension is large. When the near-field calibration antenna has an azimuth dimension offset, the phase of the original calibration value of each channel of the near-field calibration antenna will have certain characteristics, and such characteristics are reflected in the slope. Therefore, by dividing the original calibration value of each channel into M segments by row, performing phase unwrapping operations on each segment respectively, obtaining M phase vectors, and performing linear fitting on each phase vector respectively, the slope value corresponding to each row can be estimated, and then based on the slope value corresponding to each row, matching is performed in the pre-constructed offset error slope corresponding table, matching the closest error slope for each row, returning the corresponding offset, and the estimated offset can be calculated. Finally, the phase difference caused by the estimated offset of each channel is calculated respectively, and the original calibration value is compensated based on the calculated phase difference to obtain the compensated calibration value, and the calibration coefficient is corrected based on the compensated calibration value. The measurement error of the high-frequency radar caused by the offset of the near-field calibration antenna during the near-field calibration process is avoided, and the calibration compensation accuracy is improved.

[0077] The step division of the above methods is only for clear description. When implemented, they can be combined into one step or some steps can be split and decomposed into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this application; adding insignificant modifications to the algorithm or process or introducing insignificant designs without changing the core design of the algorithm and process are all within the scope of protection of this application.

[0078] Another embodiment of the present application proposes a near-field calibration system based on near-field antenna offset error estimation. The implementation details of the near-field calibration system based on near-field antenna offset error estimation proposed in this embodiment are specifically described below. The following content is only for the convenience of understanding the implementation details provided, and is not necessary for implementing this example. Figure 6 This is a structural diagram of a near-field calibration system based on near-field antenna offset error estimation proposed in this embodiment, the system comprising: a near-field test antenna 201, a table building module 202, an original calibration module 203, an unwinding and linear fitting module 204, a table lookup matching module 205, a compensation module 206 and a calibration coefficient correction module 207.

[0079] The table building module 202 is used to build an offset error slope correspondence table.

[0080] The original calibration module 203 is used to perform near-field calibration on the target phased array antenna 300 using the near-field test antenna 201, obtain the phase value of each channel of the target phased array antenna 300 in the current state, and compare the phase value of each channel with the pre-acquired near-field reference data to obtain the original calibration value of each channel, wherein the target phased array antenna 300 has M rows and N columns, with a total of M×N channels.

[0081] The unwrapping and linear fitting module 204 is used to divide the original calibration value of each channel into M segments by row, perform phase unwrapping operation on each segment to obtain M phase vectors, and perform linear fitting on each phase vector to estimate the slope value corresponding to each row.

[0082] The table lookup matching module 205 is used to match the pre-built offset error slope corresponding table based on the slope value corresponding to each row, match the closest error slope for each row, return the corresponding offset, and calculate the estimated offset based on each offset.

[0083] The compensation module 206 is used to respectively calculate the phase difference of each channel caused by the estimated offset, and compensate the original calibration value based on the calculated phase difference to obtain a compensated calibration value.

[0084] The calibration coefficient correction module 207 is used to correct the calibration coefficient based on the compensated calibration value.

[0085] It is worth mentioning that all modules involved in this embodiment are logic modules. In practical applications, a logic unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. In addition, in order to highlight the innovative part of this application, this embodiment does not introduce units that are not closely related to solving the technical problems proposed by this application, but this does not mean that there are no other units in this embodiment.

[0086] It is not difficult to find that this embodiment is a system embodiment corresponding to the above method embodiment, and this embodiment can be implemented in conjunction with the above method embodiment. The relevant technical details and technical effects mentioned in the above embodiments are still valid in this embodiment, and in order to reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied in the above embodiments.

[0087] Another embodiment of the present application provides an electronic device, whose specific structure is as follows: Figure 7As shown, it includes: at least one processor 401; and a memory 402 that is communicatively connected to the at least one processor 401; wherein the memory 402 stores instructions that can be executed by the at least one processor 401, and the instructions are executed by the at least one processor 401 so that the at least one processor 401 can execute a near-field calibration method based on near-field antenna offset error estimation as described in the above-mentioned method embodiments.

[0088] Among them, the memory and the processor can be connected in a bus manner, and the bus can include any number of interconnected buses and bridges, and the bus connects various circuits of one or more processors and memories together. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are all well known in the art and will not be further described in this article. The bus interface is responsible for providing an interface between the bus and the transceiver. The transceiver can be one component or multiple components, such as multiple receivers and transmitters, providing a unit for communicating with various other devices on a transmission medium. The data processed by the processor is transmitted on a wireless medium through an antenna, and further, the antenna also receives data and transmits the data to the processor.

[0089] The processor is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory can be used to store data used by the processor when performing operations.

[0090] Another embodiment of the present application proposes a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it can implement a near-field calibration method based on near-field antenna offset error estimation as described in the above method embodiments.

[0091] That is, those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including a number of instructions to enable a device (such as a single-chip microcomputer, chip, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM (Read-Only Memory), RAM (Random Access Memory), disk or optical disk and other media that can store program codes.

[0092] Those skilled in the art will appreciate that the above embodiments are specific embodiments for implementing the present application, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. A near-field calibration method based on near-field antenna offset error estimation, characterized in that: include: The target phased array antenna is calibrated in the near field by using the near field test antenna to obtain the phase value of each channel of the target phased array antenna in the current state, and the phase value of each channel is compared with the pre-acquired near field reference data to obtain the original calibration value of each channel; wherein the target phased array antenna has M rows and N columns, with a total of M×N channels; The original calibration value of each channel is divided into M segments by row, and phase unwrapping operation is performed on each segment to obtain M phase vectors, and linear fitting is performed on each phase vector to estimate the slope value corresponding to each row; Based on the slope value corresponding to each row, a match is performed in the pre-built offset error slope corresponding table, the closest error slope is matched for each row, the corresponding offset is returned, and the estimated offset is calculated based on each offset; The phase difference of each channel caused by the estimated offset is calculated respectively, and the original calibration value is compensated based on the calculated phase difference to obtain a compensated calibration value; The calibration coefficient is corrected based on the compensated calibration value.

2. A near-field calibration method based on near-field antenna offset error estimation according to claim 1, characterized in that: The target phased array antenna has 4 rows and N columns, with a total of 4N channels. The original calibration value of each channel is divided into M segments by row, and phase unwrapping operations are performed on each segment to obtain M phase vectors. Linear fitting is performed on each phase vector to estimate the slope value corresponding to each row, including: The original calibration value of each channel is divided into four sections {[1:N], [N+1:2N], [2N+1:3N], [3N+1:4N]} by row, which are recorded as L1, L2, L3 and L4 respectively; Perform phase unwrapping operation on each segment of data to obtain the phase vector corresponding to each row, which are recorded as Φ1, Φ2, Φ3 and Φ4 respectively. The phase unwrapping operation is specifically to expand L m The radian phase angle in m = 1, 2, 3, 4, whenever the jump between consecutive radian phase angles is greater than or equal to π, the phase angle is shifted by increasing the integer multiple of ±2π until the jump between consecutive radian phase angles is less than v; Linear fitting is performed on the phase vector corresponding to each row, and the slope value corresponding to each row is estimated, which are recorded as k1, k2, k3 and k4 respectively.

3. A near-field calibration method based on near-field antenna offset error estimation according to claim 2, characterized in that: The offset error slope correspondence table is constructed by the following steps: A near-field test geometric model is established according to the geometric positions of each channel of the target phased array antenna and the relative position coordinates of the near-field test antenna; Simulate the different degrees of deviation of the near-field test antenna in the directional dimension, and establish the deviation error slope correspondence table T based on the near-field test geometric model. m {[d mn , K mn ]}, m=1,2,3,4, n=1,2,...,N; Among them, T m The offset error slope correspondence table of the mth row, d mn Indicates the nth offset of the mth row, K mn For mn The corresponding error slope.

4. The near-field calibration method based on near-field antenna offset error estimation according to claim 3, characterized in that: After linear fitting is performed on each phase vector to estimate the slope value corresponding to each row, and before matching is performed in a pre-constructed offset error slope corresponding table based on the slope value corresponding to each row, the method further includes: Calculate the mean slope of the slope values ​​corresponding to each row And calculate the slope variance S of the slope values ​​corresponding to each row 2 , Determine the slope variance S 2 Is it greater than the preset variance threshold? If the slope variance S 2 Greater than the variance threshold Then the original calibration value is directly used to correct the calibration coefficient; If the slope variance S 2 Less than or equal to the variance threshold Based on the slope value corresponding to each row, a match is performed in the pre-constructed offset error slope correspondence table.

5. A near-field calibration method based on near-field antenna offset error estimation according to claim 4, characterized in that: Based on the slope value corresponding to each row, a match is performed in the pre-built offset error slope correspondence table, the closest error slope is matched for each row, and the corresponding offset is returned, including: From the offset error slope corresponding tables T1, T2, T3, and T4, respectively, match the error slope K closest to k1, k2, k3, and k4. 1min , K 2min , K 3min , K 4min , and return the corresponding offsets d1, d2, d3, d4; The table lookup matching process is implemented by the following formula: K 1min =my i {abs(k1-K 1i )}; K 2min =min j {abs(k2-K 2j )}; K 3min =min p {abs(k3-K 3p )}; K 4min =my q {abs(k4-K 4q )}; Where abs(·) means to find the absolute value, K 1i represents the i-th error slope in T1, K 2j represents the jth error slope in T2, K 3p represents the pth error slope in T3, K 4q represents the qth error slope in T4; The estimated offset is calculated based on each offset and is implemented using the following formula: in, is the calculated estimated offset.

6. A near-field calibration method based on near-field antenna offset error estimation according to claim 5, characterized in that: Calculate the phase difference of each channel due to the estimated offset, including: The center of the target phased array antenna is taken as the coordinate origin, the X coordinate is the vertical direction of the array plane, the Y coordinate is the horizontal direction, and the Z coordinate is the elevation direction. It is assumed that the near-field calibration antenna is directly above the center of the array. Assume that the initial position coordinates of the near-field calibration antenna are (X0,0,0) and the position coordinates of the bth channel are (x b ,y b ,z b ), the phase difference of each channel due to the estimated offset is calculated by the following formula: Where b = 1, 2, ..., 4N, λ is the preset adjustment parameter, represents the phase difference of the bth channel due to the estimated offset; The original calibration value is compensated based on the calculated phase difference to obtain the compensated calibration value, which is achieved by the following formula: in, is the original calibration value of the bth channel, is the calibration value after compensation of the bth channel.

7. A near-field calibration method based on near-field antenna offset error estimation according to any one of claims 1 to 6, characterized in that: The near-field reference data is obtained by synchronously measuring the near-field data when performing far-field calibration on the target phased array antenna.

8. A near-field calibration system based on near-field antenna offset error estimation, characterized in that: include: Near-field test antenna, table building module, original calibration module, unwinding and linear fitting module, table lookup matching module, compensation module and calibration coefficient correction module; A table building module is used to build a corresponding table of offset error slope; The original calibration module is used to perform near-field calibration on the target phased array antenna using the near-field test antenna, obtain the phase value of each channel of the target phased array antenna in the current state, and compare the phase value of each channel with the pre-acquired near-field reference data to obtain the original calibration value of each channel, wherein the target phased array antenna has M rows and N columns, with a total of M×N channels; The unwrapping and linear fitting module is used to divide the original calibration value of each channel into M segments by row, perform phase unwrapping operation on each segment to obtain M phase vectors, and perform linear fitting on each phase vector to estimate the slope value corresponding to each row; A table lookup matching module is used to match the slope value corresponding to each row in a pre-built offset error slope corresponding table, match the closest error slope for each row, return the corresponding offset, and calculate the estimated offset based on each offset; A compensation module is used to calculate the phase difference of each channel caused by the estimated offset, and compensate the original calibration value based on the calculated phase difference to obtain a compensated calibration value; The calibration coefficient correction module is used to correct the calibration coefficient based on the compensated calibration value.

9. An electronic device, characterized in that: include: at least one processor; and, a memory communicatively coupled to the at least one processor; In which, the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute a near-field calibration method based on near-field antenna offset error estimation as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, it is possible to implement a near-field calibration method based on near-field antenna offset error estimation as described in any one of claims 1 to 7.

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