Signal processing method and system for dual-polarization signal receiver

Abstract

The embodiment of the invention discloses a signal processing method and device for a dual-polarization signal receiver. The method comprises the following steps: determining priorities of cross polarization interference and IQ imbalance interference on a signal to be processed; and configuring a loop working sequence based on the priority, and performing signal processing based on the configured loop working sequence. According to the priority of cross polarization interference and IQ imbalance interference on received signals, the loop working sequence can be flexibly configured, main interference is preferentially eliminated, higher convergence speed and higher convergence precision are achieved, and the application range of the dual-polarization receiver is widened. The problems that XPIC, the effect of balancing and eliminating IQ imbalance are poor, and the frame efficiency is reduced due to the fact that pilot frequency assistance is adopted in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of signal processing, and particularly relates to a signal processing method and device for a dual-polarization signal receiver. Background Art

[0002] Millimeter-wave communication is a typical communication technology with a high-quality and constant-parameter wireless transmission channel, and is widely used in application scenarios with high rate and large bandwidth. Under the requirement of further improving the communication rate, the polarization multiplexing technology is widely used in high-rate and large-bandwidth millimeter-wave communication because it can simultaneously transmit independent signals in the same frequency band by using two orthogonal polarizations, which can significantly improve the spectrum utilization rate.

[0003] In a large-bandwidth scenario, due to the performance limitations of existing analog-to-digital conversion (A / D) and digital-to-analog conversion (D / A) devices, when receiving broadband signals up to several GHz or even dozens of GHz, only a zero-intermediate-frequency receiver architecture can be adopted to completely collect analog signals. Since the in-phase (I) and quadrature (Q) signals of the receiver in the zero-intermediate-frequency architecture need to be separated by an analog mixer, due to the non-ideality of the hardware circuit (such as gain mismatch and phase deviation), amplitude and phase imbalance will occur between the IQ two signals. Moreover, in practice, the polarization isolation devices in the dual-polarization system cannot achieve complete isolation and non-interference, the two signals are not completely orthogonal, and depolarization effects will occur when electromagnetic waves pass through inhomogeneous media such as raindrops, thereby introducing cross-polarization interference. These interferences are superimposed on the influence of the multipath channel, especially in the case of high-order modulation such as 16 / 64QAM, which will cause a great deterioration of the bit error rate.

[0004] Commonly used XPIC, equalization, and IQ imbalance cancellation often require pilot assistance and are carried out in the frequency domain. This reduces the frame efficiency of high-speed communication. Separating these three steps, the errors in the pre-stage processing will affect the subsequent processing, making these interferences unable to be completely eliminated. Such processing has an impact on the effectiveness and reliability of the communication system. Therefore, the traditional method is not applicable in a large-bandwidth dual-polarization receiver. Summary of the Invention

[0005] The main purpose of the present invention is to provide a signal processing method and system for a dual-polarization signal receiver to solve the deficiencies in the related art.

[0006] To achieve the above object, according to the first aspect of the present invention, there is provided a signal processing method for a dual-polarization signal receiver, including determining the priority of cross-polarization interference and IQ imbalance interference on the signal to be processed; configuring the loop working order based on the priority, and performing signal processing based on the configured loop working order, wherein the loop includes a timing synchronization module, a first set of transversal filters, and a second set of transversal filters, and the signal interference processing is completed by changing the input order of the output signal of the timing synchronization module to the first set of transversal filters and the second set of transversal filters preferentially, and configuring different signal processing methods based on the input order.

[0007] Optionally, changing the input order of the output signal of the timing synchronization module to the first set of transversal filters and the second set of transversal filters preferentially, and configuring different signal processing methods based on the order to complete signal interference processing includes: if the priority indicates that cross-polarization interference is dominant, the horizontal polarization direction signal and the vertical polarization direction signal of the output signal of the timing synchronization module are respectively input into the first set of transversal filters, wherein, after the outputs of the transversal filters in the first set of transversal filter groups are respectively fused with the horizontal polarization direction signal and the vertical polarization direction signal, the coefficients of the first set of transversal filters are updated based on the first fusion result obtained by fusion; the first fusion result and the conjugate of the first fusion result are input into the second set of transversal filters, and after the outputs of the respective transversal filters in the second set of transversal filter groups are fused, a second fusion result is obtained, that is, the horizontal and vertical polarization direction signals after XPIC, equalization, and elimination of IQ imbalance; the coefficients of the transversal filters in the second set of transversal filter groups are updated based on the second fusion result.

[0008] Optionally, if the priority indicates that IQ imbalance interference is dominant, the horizontal polarization direction signal, the conjugate of the horizontal polarization direction signal, the vertical polarization direction signal, and the conjugate of the vertical polarization direction signal of the output signal of the timing synchronization module are respectively input into the second set of transversal filters; after the outputs of the respective transversal filters in the second set of transversal filter groups are fused, a third fusion result is obtained, wherein the coefficients of the respective transversal filters in the second set of transversal filter groups are updated based on the third fusion result; the third fusion result is input into the first set of transversal filters, and after the outputs of the respective transversal filters in the first set of transversal filter groups are fused, a fourth fusion result is obtained, that is, the horizontal and vertical polarization direction signals after XPIC, equalization, and elimination of IQ imbalance; the coefficients of the respective transversal filters in the first set of transversal filter groups are updated based on the fourth fusion result.

[0009] Optionally, the outputs of the transversal filters in the first set of transversal filter banks are respectively fused with the horizontally polarized signal and the vertically polarized signal. Updating the coefficients of the first set of transversal filters based on the first fusion result obtained by the fusion includes: adding the horizontally polarized signal and the signal obtained by processing the vertically polarized signal through one transversal filter; driving the update of the coefficients of the one transversal filter using an adaptive algorithm based on the output of the first addition result obtained by the first addition; adding the horizontally and vertically polarized signals and the signal obtained by processing the horizontally polarized signal through another transversal filter, and driving the update of the coefficients of the one transversal filter using an adaptive algorithm based on the second addition result obtained by the addition.

[0010] Optionally, inputting the first fusion result and the conjugate of the first fusion result into the second set of transversal filters. After fusing the outputs of the respective transversal filters in the second set of transversal filter banks, the second fusion result includes: respectively inputting the first addition result and the conjugate of the first addition result into the first sub-transversal filter and the second sub-transversal filter in the second set of transversal filters, and after adding the outputs of the first sub-transversal filter and the second sub-transversal filter, outputting the horizontally polarized signal after joint interference cancellation, wherein, driving the update of the coefficients of the first sub-transversal filter and the second sub-transversal filter using an adaptive algorithm based on the output of the horizontally polarized signal after joint interference cancellation; respectively inputting the second addition result and the conjugate of the second addition result into the third sub-transversal filter and the fourth sub-transversal filter of the second set of transversal filters, and after adding the outputs of the third sub-transversal filter and the fourth sub-transversal filter, outputting the vertically polarized signal after joint interference cancellation, wherein, driving the update of the coefficients of the first sub-transversal filter and the second sub-transversal filter using an adaptive algorithm based on the output of the vertically polarized signal after joint interference cancellation.

[0011] Optionally, the horizontal polarization direction signal of the output signal of the timing synchronization module, the conjugate of the horizontal polarization direction signal, the vertical polarization direction signal, and the conjugate of the vertical polarization direction signal are respectively input into the second group of transversal filters; after fusing the outputs of the respective transversal filters in the second group of transversal filter banks, the third fusion result obtained includes: inputting the horizontal polarization direction signal and the conjugate of the horizontal polarization direction signal into the fifth sub-transversal filter and the sixth sub-transversal filter; adding the output results of the fifth sub-transversal filter and the sixth sub-transversal filter to obtain a third addition result, wherein the coefficients of the fifth sub-transversal filter and the sixth sub-transversal filter are updated by an adaptive algorithm based on the output third addition result; inputting the vertical polarization direction signal and the conjugate of the vertical direction signal into the sixth transversal filter and the seventh transversal filter; adding the output results of the sixth transversal filter and the seventh transversal filter to obtain a fourth addition result, wherein the coefficients of the sixth transversal filter and the seventh transversal filter are updated by an adaptive algorithm based on the output fourth addition result.

[0012] Optionally, input the third fusion result into the first group of transversal filters. After fusing the outputs of the respective transversal filters in the first group of transversal filter banks, the fourth fusion result obtained includes: inputting the fourth addition result into the eighth transversal filter in the first group of transversal filters, and adding the output of the eighth transversal filter to the third addition result to obtain the horizontal polarization direction signal after joint interference cancellation, wherein the coefficient of the eighth transversal filter is updated by an adaptive algorithm based on the output horizontal polarization direction signal after joint interference cancellation; inputting the third addition result into the ninth transversal filter in the first group of transversal filters, and adding the output of the ninth transversal filter to the fourth addition result to obtain the vertical polarization direction signal after joint interference cancellation, wherein the coefficient of the ninth transversal filter is updated by an adaptive algorithm based on the output vertical polarization direction signal after joint interference cancellation.

[0013] Optionally, when updating the coefficients of the transversal filter by an adaptive algorithm, the method includes: determining the real part of the first-stage error and the imaginary part of the first-stage error based on the output signal in the first stage; determining the first-stage error based on the real part of the first-stage error and the imaginary part of the first-stage error; in the second stage after the eye diagram opens, for 64QAM, determining 4 decision regions, and determining the real part of the second-stage error and the imaginary part of the second-stage error based on the decision regions; determining the second-stage error based on the real part of the second-stage error and the imaginary part of the second-stage error.

[0014] According to a second aspect of the present invention, there is provided a signal processing system for a dual-polarization signal receiver, including a processing module, a timing synchronization module forming a loop, a first set of transversal filters, and a second set of transversal filters; wherein, the processing module determines the priority of the cross-polarization interference and IQ imbalance interference on the signal to be processed, and configures the working order of the loop based on the priority; by changing the input order of the output signal of the timing synchronization module to the first set of transversal filters and the second set of transversal filters preferentially, and configuring different signal processing methods based on the input order to complete signal interference processing.

[0015] Optionally, by changing the order of the output signal of the timing synchronization module preferentially input to the first set of transversal filters and the second set of transversal filters, and configuring different signal processing methods based on the order to complete signal interference processing includes: if the priority indicates that the cross-polarization interference is dominant, the horizontal polarization direction signal and the vertical polarization direction signal of the output signal of the timing synchronization module are respectively input to the first set of transversal filters, wherein, after the outputs of the transversal filters in the first set of transversal filter groups are respectively fused with the horizontal polarization direction signal and the vertical polarization direction signal, the coefficients of the first set of transversal filters are updated based on the first fusion result obtained by the fusion; the first fusion result and the conjugate of the first fusion result are input to the second set of transversal filters, and after the outputs of the respective transversal filters in the second set of transversal filter groups are fused, a second fusion result is obtained, that is, the XPIC, the horizontal and vertical polarization direction signals after equalizing and eliminating IQ imbalance; the coefficients of the transversal filters in the second set of transversal filter groups are updated based on the second fusion result

[0016] According to a third aspect of the present invention, there is provided a computer-readable storage medium storing computer instructions for causing the computer to execute the method according to any one of the first aspects.

[0017] According to a fourth aspect of the present invention, there is provided an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to cause the at least one processor to execute the method according to any one of the implementation manners of the first aspect.

[0018] The signal processing method and device for a dual-polarization signal receiver in this embodiment, where the method includes determining the priority of cross-polarization interference and IQ imbalance interference on the signal to be processed; configuring the working order of the loop based on the priority, and performing signal processing based on the configured working order of the loop. Among them, the loop includes a timing synchronization module, a first set of transversal filters, and a second set of transversal filters. By changing the input order of the output signal of the timing synchronization module to the first set of transversal filters and the second set of transversal filters preferentially, and configuring different signal processing methods based on the input order to complete signal interference processing. By adjusting the signal input and output interfaces according to the priority of cross-polarization interference and IQ imbalance interference on the received signal, the working order of the loop is configured. According to the priority of cross-polarization interference and IQ imbalance interference on the received signal, the working order of the loop can be flexibly configured to preferentially eliminate the main interference, achieving a faster convergence speed and a higher convergence accuracy, and improving the applicable range of the dual-polarization receiver. It overcomes the problems in the related technology that the effects of XPIC, equalization, and elimination of IQ imbalance are not good, and the frame efficiency is reduced by using pilot assistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 is the flowchart of the signal processing method for a dual-polarization signal receiver according to an embodiment of the present invention;

[0021] Figure 2a is the schematic diagram of the loop input and output interface configuration when cross-polarization interference is the main interference in an embodiment of the present invention;

[0022] Figure 2b is the schematic diagram of the loop input and output interface configuration when IQ imbalance interference is the main interference in an embodiment of the present invention;

[0023] Figure 3a is an application schematic diagram of the loop input and output interface configuration when cross-polarization interference is the main interference in an embodiment of the present invention;

[0024] Figure 3b is an application schematic diagram of the loop input and output interface configuration when IQ imbalance interference is the main interference in an embodiment of the present invention;

[0025] Figure 4a is the decision region of the 64QAM modulation method;

[0026] Figure 4b It is a schematic diagram of the constellation before the H-channel processing of the 64QAM modulation method;

[0027] Figure 4c It is a schematic diagram of the constellation after the H-channel processing of the 64QAM modulation method;

[0028] Figure 4d It is the constellation diagram before the V-channel processing of the 64QAM modulation method;

[0029] Figure 4e It is the constellation diagram after the V-channel processing of the 64QAM modulation method;

[0030] Figure 5 Schematic diagram of the comparison between joint processing for interference elimination and non-joint processing. Specific implementation manners

[0031] In order to enable those skilled in the art of the present technology to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to describe the embodiments of the present invention here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0033] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0034] According to an embodiment of the present invention, there is provided a signal processing method and device for a dual-polarization signal receiver, as Figure 1 shown, including the following steps 101 to step 103:

[0035] Step 101: Determine the priorities of the cross-polarization interference and IQ imbalance interference suffered by the signal to be processed.

[0036] In this step, the signal to be processed is input into a loop, which includes a timing synchronization module, a first set of transversal filters, and a second set of transversal filters. The center tap coefficients of the two sets of filters are compared, and the interference priority is determined based on the magnitude relationship.

[0037] Specifically, the first set of filters includes two filters, Filter_h into which the horizontally polarized signal is input and Filter_v into which the vertically polarized signal is input. The second set of filters includes four filters, Filter_X into which the horizontally polarized main signal is input, Filter_Ximag into which the horizontally polarized conjugate signal is input, Filter_Y into which the vertically polarized main signal is input, and Filter_Yimag into which the vertically polarized conjugate signal is input. The two selected filters are the center tap coefficients of Filter_h and Filter_Ximag, that is, the center tap coefficients of the filter through which the horizontally polarized signal passes in the first set of filters and the filter through which the horizontally polarized conjugate signal passes in the second set of filters, respectively used to characterize the intensities of cross-polarization interference and IQ imbalance interference. Compare the magnitudes of their center tap coefficients. If the center tap coefficient of Filter_h into which the horizontally polarized signal is input in the first set of filters is larger, then the cross-polarization interference is the priority interference; otherwise, the IQ imbalance interference is the priority interference.

[0038] Step 102: Configure the working order of the loop based on the priority, and perform signal processing based on the configured working order of the loop. The loop includes a timing synchronization module, a first set of transversal filters, and a second set of transversal filters. The signal interference is processed by changing the input order of the output signal of the timing synchronization module to the first set of transversal filters and the second set of transversal filters preferentially, and configuring different signal processing methods based on the input order.

[0039] In this step, for the signals after symbol timing synchronization in the horizontal polarization direction and the vertical polarization direction, first determine the priority of the received signal being affected by cross-polarization interference and IQ imbalance interference, and configure the working order of the loop according to the interference priority. Refer to Figure 2a shows the configuration of the loop input and output interfaces when cross-polarization interference is the main interference. The signals after symbol timing synchronization in the horizontal polarization direction and the vertical polarization direction pass through the first set and the second set of filters respectively to complete interference cancellation. Figure 2b shows the configuration of the loop input and output interfaces when IQ imbalance interference is the main interference. The signals after symbol timing synchronization in the horizontal polarization direction and the vertical polarization direction pass through the second set of filters and the first set of filters respectively and then are output.

[0040] If cross-polarization interference is the main interference, first input the horizontally polarized signal into a transversal filter, add the output result of the filter to the vertically polarized signal, and update the tap coefficients of the transversal filter by calculating the error based on the addition result; separately pass the addition result itself and its conjugate through two independent transversal filters, add the two filtering results to obtain the vertically polarized signal after XPIC, equalization, and elimination of IQ imbalance. The coefficients of these two transversal filters are updated by calculating the error separately based on the output result; the error calculation of the transversal filter adopts dual-mode update. For the 64QAM modulation mode, first use the MCMA algorithm to improve the decision accuracy, and switch to the MAMA algorithm mode after the eye diagram opens. Apply the same and symmetric processing method to the other signal path to obtain the signals of both the horizontal polarization and the vertical polarization after completing XPIC, equalization, and elimination of IQ imbalance. If IQ imbalance interference is the main interference, modify the signal connection topology, first input the signal and its conjugate into the second group of two filters, and then input the result into the first group of filters to obtain the signal after interference elimination.

[0041] All the above calculations do not require pilot assistance, so the frame efficiency can be improved and the communication effectiveness can be enhanced; the joint processing means that XPIC, equalization, and IQ imbalance are carried out simultaneously and the filter coefficients are updated iteratively at the same time, so the residual error of the previous-stage processing affecting the subsequent processing can be improved, the effects of XPIC, equalization, and elimination of IQ imbalance can be enhanced, the performance of the dual-polarization receiver can be improved, and the communication reliability can be enhanced.

[0042] Since all the processing is carried out in the time domain, there is no need to convert the data to the frequency domain, and no additional DFT and IDFT processing are required, which can greatly reduce the resource consumption from the overall system.

[0043] As an optional implementation manner of this embodiment, the signal interference processing is completed by changing the order in which the output signal of the timing synchronization module is preferentially input to the first set of horizontal filters and the second set of horizontal filters, and configuring different signal processing manners based on the order, including: if the priority indication indicates that the cross-polarization interference is dominant, the horizontal polarization direction signal and the vertical polarization direction signal of the output signal of the timing synchronization module are respectively input to the first set of horizontal filters. Among them, after the outputs of the horizontal filters in the first set of horizontal filter groups are respectively fused with the horizontal polarization direction signal and the vertical polarization direction signal, the coefficients of the first set of horizontal filters are updated based on the first fusion result obtained by the fusion; the first fusion result and the conjugate of the first fusion result are input to the second set of horizontal filters, and after the outputs of the horizontal filters in the second set of horizontal filter groups are fused, a second fusion result is obtained, that is, the horizontal and vertical polarization direction signals after XPIC, equalization, and elimination of IQ imbalance; the coefficients of the horizontal filters in the second set of horizontal filter groups are updated based on the second fusion result.

[0044] As an optional implementation manner of this embodiment, the outputs of the horizontal filters in the first set of horizontal filter groups are respectively fused with the horizontal polarization direction signal and the vertical polarization direction signal, and the coefficients of the first set of horizontal filters are updated based on the first fusion result obtained by the fusion, including: adding the horizontal polarization direction signal and the signal obtained by processing the vertical polarization direction signal through one horizontal filter; driving the update of the coefficients of the one horizontal filter by using an adaptive algorithm based on the first addition result output after the first addition; adding the horizontal and vertical polarization direction signals and the signal obtained by processing the horizontal polarization direction signal through another horizontal filter, and driving the update of the coefficients of the one horizontal filter by using an adaptive algorithm based on the second addition result obtained by the addition.

[0045] As an alternative implementation of this embodiment, the first fusion result and the conjugate of the first fusion result are input into the second set of transversal filters. After fusing the outputs of each transversal filter in the second set of transversal filters, the second fusion result includes: inputting the first addition result and the conjugate of the first addition result into the first sub-transversal filter and the second sub-transversal filter in the second set of transversal filters respectively. After adding the outputs of the first sub-transversal filter and the second sub-transversal filter, the horizontally polarized direction signal after joint interference cancellation is output. Among them, based on the output horizontally polarized direction signal after joint interference cancellation, an adaptive algorithm is used to drive the update of the transversal filter coefficients of the first sub-transversal filter and the second sub-transversal filter; inputting the second addition result and the conjugate of the second addition result into the third sub-transversal filter and the fourth sub-transversal filter of the second set of transversal filters respectively. After adding the outputs of the third sub-transversal filter and the fourth sub-transversal filter, the vertically polarized direction signal after joint interference cancellation is output. Among them, based on the output vertically polarized direction signal after joint interference cancellation, an adaptive algorithm is used to drive the update of the transversal filter coefficients of the first sub-transversal filter and the second sub-transversal filter.

[0046] In this alternative implementation, referring to Figure 3a , if the signal is mainly affected by cross-polarization interference, for the vertically polarized direction signal V_input(k) after symbol timing synchronization, it is input to a transversal filter Filter h , and multiplied by the conjugate of the filter coefficient WV. This transversal filter is of order 1. Add the output of the filter to the horizontally polarized direction signal H_input(k) after symbol timing synchronization to obtain H_process(k). Then H_process(k) is:

[0047] H_process(k) = H_input(k) + V_input(k) * conj(WV)

[0048] Furthermore, the obtained signal H1 is used to calculate the error Error h (k); the error Error h (k) calculated is used to calculate the coefficient WV of the transversal filter Filter h : WV(k + 1) = WV(k) + μ(k) * V_input(k) * conj(Error h (k)); the obtained signal H_process(k) is input to a transversal filter Filter in the second set of transversal filters X, perform a filtering operation with the conjugate of the filter coefficient WX to obtain X_process(k). The order of this transversal filter is 64. When filtering, first perform a 64-point delay operation on the input signal to match the order of the transversal filter. X_process(k) = H_process(k) * conj(WX(k) T ). Specifically, the order of this transversal filter is 64, that is, the filter coefficient WX0 = [WX0(0), WX0(1), WX0(2), …, WX0(63)]. When filtering, first perform a 64-point delay operation on the input signal to obtain [H_process 0-63 ~H_process0] to match the order of the transversal filter. The initial value of the delay is set to 0. When the next step is executed for the 64th time, the delay sequence in the filter is [H_process0, H_process1, H_process2, …, H_process 63 . X_process0 = [H_process0~H_process 0-63 * conj(WX0 T ).

[0049] Further, input the conjugate of the obtained signal H_process(k) to another transversal filter FilterX imag , perform a filtering operation with the conjugate of the filter coefficient WX_imag to obtain X_imagprocess(k). This transversal filter is of order 64. X_imagprocess(k) = conj(H_process(k)) * conj(WX_imag(k) T ). Add the obtained results and output them, that is, obtain the horizontally polarized direction signal H after interference cancellation. H(k) = X_process(k) + X_imagprocess(k) 。 Use the obtained H to calculate the error Error X ; calculate the coefficients WX of the transversal filter Filter X and the coefficients WX_imag of the transversal filter Filter Ximag based on the calculated error. WX(k + 1) = WX(k) + μ(k) * H(k) * conj(Error X (k)), WX_imag(k + 1) = WX_imag(k) + μ(k) * conj(H(k)) * conj(Error X (k)).

[0050] For the vertically polarized direction signal V_input(k) after symbol timing synchronization in the above process, the horizontally polarized direction signal H_input after symbol timing synchronization can be processed in the same way to obtain the vertically polarized direction signal V after interference cancellation.

[0051] As an alternative implementation of this embodiment, if the priority indication is mainly affected by IQ imbalance, the horizontally polarized direction signal of the output signal of the timing synchronization module, the conjugate of the horizontally polarized direction signal, the vertically polarized direction signal, and the conjugate of the vertically polarized direction signal are respectively input into the second group of transversal filters; after fusing the outputs of each transversal filter in the second group of transversal filter banks, a third fusion result is obtained, wherein the coefficients of each transversal filter in the second group of transversal filter banks are updated based on the third fusion result; the third fusion result is input into the first group of transversal filters, and after fusing the outputs of each transversal filter in the first group of transversal filter banks, a fourth fusion result is obtained, that is, the horizontally and vertically polarized direction signals after XPIC, equalization, and cancellation of IQ imbalance; the coefficients of each transversal filter in the first group of transversal filter banks are updated based on the fourth fusion result.

[0052] In this alternative implementation, if the IQ imbalance interference is the main interference, the signal connection topology is modified, and the signal and its conjugate are first input to two filters in the second group, and the result is then input to the first group of filters to obtain the signal after interference cancellation.

[0053] As an alternative implementation of this embodiment, the horizontally polarized direction signal of the output signal of the timing synchronization module, the conjugate of the horizontally polarized direction signal, the vertically polarized direction signal, and the conjugate of the vertically polarized direction signal are respectively input into the second group of transversal filters; after fusing the outputs of each transversal filter in the second group of transversal filter banks, the third fusion result includes: inputting the horizontally polarized direction signal and the conjugate of the horizontally polarized direction signal into the fifth sub-transversal filter and the sixth sub-transversal filter; adding the output results of the fifth sub-transversal filter and the sixth sub-transversal filter to obtain a third addition result, wherein the coefficients of the fifth sub-transversal filter and the sixth sub-transversal filter are updated by an adaptive algorithm based on the output third addition result; inputting the vertically polarized direction signal and the conjugate of the vertical direction signal into the sixth transversal filter and the seventh transversal filter; adding the output results of the sixth transversal filter and the seventh transversal filter to obtain a fourth addition result, wherein the coefficients of the sixth transversal filter and the seventh transversal filter are updated by an adaptive algorithm based on the output fourth addition result.

[0054] Input the third fusion result into the first group of horizontal filters. After fusing the outputs of the horizontal filters in the first group of horizontal filter banks, the obtained fourth fusion result includes: input the fourth addition result into the eighth horizontal filter in the first group of horizontal filters, and add the output of the eighth horizontal filter to the third addition result to obtain the horizontally polarized direction signal after joint interference cancellation, where the coefficient of the eighth horizontal filter is updated by an adaptive algorithm based on the output horizontally polarized direction signal after joint interference cancellation; input the third addition result into the ninth horizontal filter in the first group of horizontal filters, and add the output of the ninth horizontal filter to the fourth addition result to obtain the vertically polarized direction signal after joint interference cancellation, where the coefficient of the ninth horizontal filter is updated by an adaptive algorithm based on the output vertically polarized direction signal after joint interference cancellation.

[0055] Reference Figure 3b , if the IQ imbalance interference is the main interference, for the vertically polarized direction signal and the horizontally polarized direction signal after symbol timing synchronization, they are respectively processed by the second group of filters and the first group of filters. This process is the same as the processing method for the vertically polarized direction signal V_input(k) after symbol timing synchronization described above, and will not be elaborated here.

[0056] All the above calculations do not require pilot assistance, so the frame efficiency can be improved and the communication effectiveness can be enhanced; the joint processing means that XPIC, equalization, and IQ imbalance are carried out simultaneously and the filter coefficients are updated iteratively at the same time, so the residual error of the previous stage processing can be improved to affect the subsequent processing, the effects of XPIC, equalization, and IQ imbalance elimination can be enhanced, the performance of the dual-polarized receiver can be improved, and the communication reliability can be enhanced.

[0057] As an optional implementation manner of this embodiment, when updating the coefficients of the horizontal filter by an adaptive algorithm, the method includes: determining the real part of the first-stage error and the imaginary part of the first-stage error based on the output signal in the first stage; determining the first-stage error based on the real part of the first-stage error and the imaginary part of the first-stage error; in the second stage after the eye diagram opens, for 64QAM, determining 4 judgment domains, and determining the real part of the second-stage error and the imaginary part of the second-stage error based on the judgment domains; determining the second-stage error based on the real part of the second-stage error and the imaginary part of the second-stage error.

[0058] In this optional implementation manner, not only the occupation of the pilot sequence bandwidth in the traditional method is avoided through blind processing, the channel overhead is reduced, but also the mismatch between the channel responses of the valid data at the frame head and the frame tail in the long frame structure of the traditional method is avoided by adaptively and continuously adjusting the parameters, and the time-varying channel can be dynamically tracked to enhance the adaptability of the system.

[0059] During the error calculation process, an error can be used to continuously drive the update of a coefficient. Essentially, it belongs to parallel signal processing and can arbitrarily expand the parallelism. When the clock of the logic device is limited and the symbol rate is too high, it can still work properly to achieve XPIC, equalization, and IQ imbalance cancellation at ultra-high speeds.

[0060] Taking the case where the signal is mainly affected by cross-polarization interference and the signal processing process in the vertical polarization direction after symbol timing synchronization as an example, when calculating the error Error h (k) using the signal H1, in the first stage of the error, the real part of the error is: Error hi (k) = Real(H_process(k)) * (R 2 - Real(H_process(k)) 2 ); the imaginary part of the error is: Error hq (k) = Imag(H_process(k)) * (R 2 - Imag(H_process(k)) 2 ), then the error is Error hq (k) = Imag(H_process(k)) * (R 2 - Imag(H_process(k)) 2 ). After the eye diagram opens, the adaptive algorithm is switched from the first stage to the second stage to complete the entire processing process.

[0061] In the second stage, for 64QAM, four decision regions R m are determined. For the 64QAM modulation method, taking the absolute values of the horizontal and vertical coordinates of the outermost standard constellation points as the standard, the complex plane is divided into four decision regions R m

[0062] Refer to Figure 4a The decision regions shown in the 64QAM modulation method. Figure 4b This is the 64QAM modulation method, with the signal-to-noise ratio E b / N0 being 30 dB, the cross-polarization isolation being 20 dB, the IQ imbalance amplitude distortion being 1 dB, the angle distortion being 2°, the multipath delay being 50 symbols, and the constellation diagram before H-path processing; Figure 4c This is the constellation diagram after H-path processing; Figure 4d This is the constellation diagram before V-path processing; Figure 4e This is the constellation diagram after V-path processing.

[0063] The real part of the error in the second stage is: Error hi (k) = min m [Real(H_process(k)) * (Rm 2 -Real(H_process(k)) 2 )], the imaginary part of the error is: Error hq (k) = min m [Imag(H_process(k)) * (R m 2 -Imag(H_process(k)) 2 )] Then the error is Error h (k) = Error hi (k) + j * Error hq k).

[0064] Reference Figure 5 The comparison between joint processing for interference cancellation and non - joint processing is shown. Set the two sets of filters to first - order, the X and Y axes are the coefficients of the two sets of filters, and the Z axis is the cost function EVM. The orange line is the convergence trajectory of the joint - processing filter coefficients decreasing, and the yellow line is the convergence trajectory of the non - joint - processing filter coefficients decreasing.

[0065] This embodiment perfectly restores the signal, and the 64QAM constellation points are clearly visible; compared with the bit - error rate curve without cancellation processing, the bit - error rate is significantly reduced during the processing. The proposed method can adapt to the influence of low cross - polarization isolation, multipath, and IQ imbalance. When performing joint processing, the coefficients of the two sets of filters start to converge simultaneously and can finally converge to the position with the lowest EVM, improving the performance of the dual - polarization receiver compared with non - joint processing. It avoids the problem of reduced frame efficiency caused by pilot - assisted in traditional methods and can flexibly configure the loop working sequence according to the main interference, achieving a faster convergence speed and higher convergence accuracy. The all - digital architecture is convenient for FPGA implementation and can be completely decoupled from the front - end RF module. The all - blind processing can improve the frame efficiency of high - speed communication and enhance the effectiveness of the communication system. The joint processing can enhance the effects of XPIC, equalization, and IQ imbalance cancellation, improving the performance of the dual - polarization receiver.

[0066] During the processing of this embodiment, the two sets of six filters work simultaneously and the filter coefficients converge simultaneously, which can avoid the influence of residual errors in the previous - stage processing on subsequent processing in traditional methods, quickly achieve the global - optimal optimization effect, and achieve the elimination of polarization interference, multipath effects, IQ imbalance and other interferences, improving the performance of the dual - polarization receiver.

[0067] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer - executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0068] According to an embodiment of the present invention, there is also provided a signal processing system for a dual-polarization signal receiver, including a processing module, and a timing synchronization module, a first group of transversal filters, and a second group of transversal filters that form a loop; wherein, the processing module determines the priority of the signal to be processed being affected by cross-polarization interference and IQ imbalance interference, and configures the working order of the loop based on the priority; by changing the input order of the output signal of the timing synchronization module being preferentially input to the first group of transversal filters and the second group of transversal filters, and configuring different signal processing methods based on the input order to complete signal interference processing.

[0069] The above are only embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A signal processing method for a dual-polarization signal receiver, characterized in that, Including: Determine the priority of cross-polarization interference and IQ imbalance interference on the signal to be processed; Configure the loop working order based on the priority, and perform signal processing based on the configured loop working order. Wherein, the loop includes a timing synchronization module, a first set of transversal filters, and a second set of transversal filters. By changing the input order of the output signal of the timing synchronization module to the first set of transversal filters and the second set of transversal filters preferentially, and configuring different signal processing methods based on the input order to complete signal interference processing.

2. The signal processing method for a dual-polarization signal receiver according to claim 1, wherein, Completing signal interference processing by changing the input order of the output signal of the timing synchronization module to the first set of transversal filters and the second set of transversal filters preferentially, and configuring different signal processing methods based on the order includes: If the priority indicates that cross-polarization interference is dominant, input the horizontal polarization direction signal and the vertical polarization direction signal of the output signal of the timing synchronization module into the first set of transversal filters respectively. Wherein, after the outputs of the transversal filters in the first set of transversal filter groups are fused with the horizontal polarization direction signal and the vertical polarization direction signal respectively, update the coefficients of the first set of transversal filters based on the first fusion result obtained by the fusion; Input the first fusion result and the conjugate of the first fusion result into the second set of transversal filters, and perform fusion on the outputs of the transversal filters in the second set of transversal filter groups to obtain a second fusion result, that is, the horizontal and vertical polarization direction signals after XPIC, equalization, and elimination of IQ imbalance; update the coefficients of the transversal filters in the second set of transversal filter groups based on the second fusion result.

3. The signal processing method for a dual-polarization signal receiver according to claim 1, characterized in that If the priority indicates that IQ imbalance interference is dominant, input the horizontal polarization direction signal, the conjugate of the horizontal polarization direction signal, the vertical polarization direction signal, and the conjugate of the vertical polarization direction signal of the output signal of the timing synchronization module into the second set of transversal filters respectively; After performing fusion on the outputs of the transversal filters in the second set of transversal filter groups, obtain a third fusion result. Wherein, update the coefficients of the transversal filters in the second set of transversal filter groups based on the third fusion result; Input the third fusion result into the first set of transversal filters, and after performing fusion on the outputs of the transversal filters in the first set of transversal filter groups, obtain a fourth fusion result, that is, the horizontal and vertical polarization direction signals after XPIC, equalization, and elimination of IQ imbalance; update the coefficients of the transversal filters in the first set of transversal filter groups based on the fourth fusion result.

4. The signal processing method for a dual-polarization signal receiver according to claim 2, wherein The outputs of the transversal filters in the first set of transversal filter groups are fused with the horizontal polarization direction signal and the vertical polarization direction signal respectively, and updating the coefficients of the first set of transversal filters based on the first fusion result obtained by the fusion includes: Add the horizontal polarization direction signal and the signal obtained by processing the vertical polarization direction signal through one transversal filter; drive the update of the coefficients of the one transversal filter by using an adaptive algorithm based on the first addition result output by the first addition. Add the signals in the horizontal and vertical polarization directions and the signal obtained by processing the horizontal polarization direction signal through another transversal filter, and drive the update of the coefficients of the one transversal filter using an adaptive algorithm based on the second addition result obtained by the addition.

5. The signal processing method for a dual-polarization signal receiver according to claim 4, wherein Input the first fusion result and the conjugate of the first fusion result into the second group of transversal filters. After fusing the outputs of the respective transversal filters in the second group of transversal filter banks, the second fusion result includes: Input the first addition result and the conjugate of the first addition result into the first sub-transversal filter and the second sub-transversal filter in the second group of transversal filters respectively. After adding the outputs of the first sub-transversal filter and the second sub-transversal filter, output the horizontal polarization direction signal after joint interference cancellation. Among them, drive the update of the coefficients of the first sub-transversal filter and the second sub-transversal filter using an adaptive algorithm based on the output horizontal polarization direction signal after joint interference cancellation; Input the second addition result and the conjugate of the second addition result into the third sub-transversal filter and the fourth sub-transversal filter of the second group of transversal filters respectively. After adding the outputs of the third sub-transversal filter and the fourth sub-transversal filter, output the vertical polarization direction signal after joint interference cancellation. Among them, drive the update of the coefficients of the first sub-transversal filter and the second sub-transversal filter using an adaptive algorithm based on the output vertical polarization direction signal after joint interference cancellation.

6. The signal processing method for a dual-polarization signal receiver according to claim 3, characterized in that, Input the horizontal polarization direction signal, the conjugate of the horizontal polarization direction signal, the vertical polarization direction signal, and the conjugate of the vertical polarization direction signal of the output signal of the timing synchronization module into the second group of transversal filters respectively; After fusing the outputs of the respective transversal filters in the second group of transversal filter banks, the obtained third fusion result includes: Input the horizontal polarization direction signal and the conjugate of the horizontal polarization direction signal into the fifth sub-transversal filter and the sixth sub-transversal filter; add the output results of the fifth sub-transversal filter and the sixth sub-transversal filter to obtain the third addition result. Among them, drive the update of the coefficients of the fifth sub-transversal filter and the sixth sub-transversal filter using an adaptive algorithm based on the output third addition result; Input the vertical polarization direction signal and the conjugate of the vertical direction signal into the sixth transversal filter and the seventh transversal filter; add the output results of the sixth transversal filter and the seventh transversal filter to obtain the fourth addition result. Among them, drive the update of the coefficients of the sixth transversal filter and the seventh transversal filter using an adaptive algorithm based on the output fourth addition result.

7. The signal processing method for a dual-polarization signal receiver according to claim 6, characterized in that, Input the third fusion result into the first group of transversal filters. After fusing the outputs of the respective transversal filters in the first group of transversal filter banks, the obtained fourth fusion result includes: Input the fourth addition result into the eighth transversal filter in the first group of transversal filters, and add the output of the eighth transversal filter to the third addition result to obtain the horizontal polarization direction signal after joint interference cancellation. Among them, drive the update of the coefficients of the eighth transversal filter using an adaptive algorithm based on the output horizontal polarization direction signal after joint interference cancellation; Input the third addition result into the ninth transversal filter in the first group of transversal filters, and add the output of the ninth transversal filter to the fourth addition result to obtain the vertically polarized direction signal after joint interference cancellation. Among them, based on the output vertically polarized direction signal after joint interference cancellation, an adaptive algorithm is used to drive the update of the coefficients of the ninth transversal filter.

8. The signal processing method for a dual-polarization signal receiver according to claims 2-7, characterized in that When using an adaptive algorithm to drive the update of the coefficients of the transversal filter, the method includes: In the first stage, determine the real part of the first-stage error and the imaginary part of the first-stage error based on the output signal; determine the first-stage error based on the real part of the first-stage error and the imaginary part of the first-stage error. In the second stage after the eye diagram opens, for 64QAM, determine 4 decision regions, and determine the real part of the second-stage error and the imaginary part of the second-stage error based on the decision regions; determine the second-stage error based on the real part of the second-stage error and the imaginary part of the second-stage error.

9. A signal processing system for a dual-polarization signal receiver, characterized in that It includes a processing module, and a timing synchronization module, a first group of transversal filters, and a second group of transversal filters that form a loop. Among them, the processing module determines the priority of the signal to be processed being affected by cross-polarization interference and IQ imbalance interference, and configures the working order of the loop based on the priority; by changing the input order of the output signal of the timing synchronization module preferentially input to the first group of transversal filters and the second group of transversal filters, and configuring different signal processing methods based on the input order to complete signal interference processing.

10. The signal processing system for a dual-polarization signal receiver according to claim 9, wherein Completing signal interference processing by changing the order of the output signal of the timing synchronization module preferentially input to the first group of transversal filters and the second group of transversal filters, and configuring different signal processing methods based on the order includes: If the priority indicates that the cross-polarization interference is the main one, then input the horizontally polarized direction signal and the vertically polarized direction signal of the output signal of the timing synchronization module into the first group of transversal filters respectively. Among them, after the outputs of the transversal filters in the first group of transversal filter groups are respectively fused with the horizontally polarized direction signal and the vertically polarized direction signal, the coefficients of the first group of transversal filters are updated based on the first fusion result obtained by the fusion. Input the first fusion result and the conjugate of the first fusion result into the second group of transversal filters, and perform fusion on the outputs of the transversal filters in the second group of transversal filter groups to obtain a second fusion result, that is, the horizontally and vertically polarized direction signals after XPIC, equalization, and elimination of IQ imbalance; update the coefficients of the transversal filters in the second group of transversal filter groups based on the second fusion result.

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