Channel correction method and device, electronic equipment and readable storage medium

Abstract

The embodiment of the invention provides a channel correction method and device, electronic equipment and a readable storage medium, and belongs to the technical field of communication. The channel correction method comprises the following steps: performing time delay adjustment on a first radio frequency signal of a first channel of a remote radio unit (RRU) according to a first time delay adjustment value to obtain a second radio frequency signal; filtering the second radio frequency signal through a correction filter to obtain a third radio frequency signal; wherein the first time delay adjustment value and the correction filter are determined based on a frequency domain correction coefficient of a first channel of the RRU, and the frequency domain correction coefficient is used for correcting an amplitude error and a phase error of the first channel.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communication technologies, and in particular, to a channel calibration method, apparatus, electronic device, and readable storage medium. Background Art

[0002] Time-division Duplex (TDD) is one of the full-duplex communication technologies used in mobile communication systems. For a TDD system, a major advantage is that it can be considered that the radio air interface channels for the uplink and downlink are reciprocal. Thus, the channel response of the corresponding downlink channel can be obtained through the Sounding Reference Signal (SRS), and further non-codebook precoding can be performed on the Physical Downlink Shared Channel (PDSCH), greatly improving its performance.

[0003] However, in actual products, affected by multiple factors such as hardware, for the baseband, the obtained channel response is affected not only by the radio air interface channel but also by hardware or external interference, resulting in certain deviations in the amplitude and phase of each antenna. Moreover, since the antenna transceiver is not the same circuit, the amplitude-phase errors of transmission and reception of each antenna are different. At this time, when precoding is performed through the SRS, the precoding gain cannot be obtained, resulting in poor transmission performance. Summary of the Invention

[0004] The embodiments of the present application provide a channel calibration method, apparatus, electronic device, and medium to solve the problem that when precoding is performed through the SRS, the precoding gain cannot be obtained, resulting in poor transmission performance.

[0005] To achieve the above object, the embodiments of the present application adopt the following technical solutions:

[0006] In a first aspect of the embodiments of the present application, a channel calibration method is provided, including: adjusting the time delay of a first radio frequency signal of a first channel of a Remote Radio Unit (RRU) according to a first time delay adjustment value to obtain a second radio frequency signal; filtering the second radio frequency signal through a calibration filter to obtain a second radio frequency signal, where the first time delay adjustment value is determined based on a frequency domain calibration coefficient of the first channel of the RRU, and the frequency domain calibration coefficient is used to calibrate the amplitude and phase errors of the first channel.

[0007] The channel calibration method provided by the embodiments of the present application determines a calibration filter and a first delay adjustment value based on the frequency-domain calibration coefficient of the first channel of the RRU, adjusts the signal delay by the first delay adjustment value, and then filters the delay-adjusted signal through time-domain filtering convolution, realizing the adjustment of the amplitude, phase, and delay of the signal in the time domain based on the frequency-domain calibration coefficient, avoiding the problem that the existing time-domain calibration scheme can only rely on the delay adjustment granularity supported by the hardware, and thus improving the transmission performance of the channel.

[0008] Combined with the first aspect, in a possible implementation manner, before adjusting the delay of the first radio frequency signal of the first channel of the RRU according to the first delay adjustment value, the channel calibration method provided by the embodiments of the present application further includes: obtaining the frequency-domain calibration coefficient of the first channel of the RRU; performing an inverse fast Fourier transform (IFFT) process on the frequency-domain calibration coefficient to obtain a corresponding time-domain sampling sequence, where the time-domain sampling sequence includes X sampling points, and X is a positive integer; determining the first delay adjustment value and the calibration filter based on the first sampling point among the X sampling points, and the first sampling point is the sampling point corresponding to the largest amplitude among the X sampling points.

[0009] Combined with the first aspect and the above possible implementation manner, in another possible implementation manner, the determining the first delay adjustment value based on the first sampling point among the X sampling points includes: determining the first delay adjustment value according to a preset filter length and the index of the first sampling point in the time-domain sampling sequence, where the preset filter length is the filter length of the preset calibration filter.

[0010] Combined with the first aspect and the above possible implementation manner, in another possible implementation manner, the determining the calibration filter based on the first sampling point among the X sampling points includes: determining first filter coefficients according to the first L sample value points and the last M sample value points of the first sampling point, and generating the calibration filter based on the first filter coefficients, where L is a positive integer less than or equal to X / 2, and M is a positive integer less than or equal to X / 2.

[0011] Combined with the first aspect and the above possible implementation manners, in another possible implementation manner, the frequency-domain correction coefficient includes at least one sample point; before performing IFFT processing on the frequency-domain correction coefficient, the method further includes: copying and flipping the first N sample points of the frequency-domain correction coefficient to obtain a first sample point sequence, and copying and flipping the last N sample points of the frequency-domain correction coefficient to obtain a second sample point sequence, where N is a positive integer; splicing the first sample point sequence, the second sample point sequence, and the at least one sample point to obtain a spliced frequency-domain correction coefficient; the performing IFFT processing on the frequency-domain correction coefficient includes: performing IFFT processing on the spliced frequency-domain correction coefficient.

[0012] Combined with the first aspect and the above possible implementation manners, in another possible implementation manner, the splicing the first sample point sequence, the second sample point sequence, and the at least one sample point to obtain a spliced frequency-domain correction coefficient includes: splicing the first sample point sequence to the starting position of the at least one sample point, and splicing the second sample point sequence to the ending position of the at least one sample point to obtain a spliced frequency-domain correction coefficient.

[0013] Combined with the first aspect and the above possible implementation manners, in another possible implementation manner, the filtering the second radio frequency signal through a correction filter to obtain a third radio frequency signal includes: inputting the second radio frequency signal into the correction filter for time-domain convolution processing, and outputting the third radio frequency signal.

[0014] In a second aspect of the embodiments of the present application, there is provided a channel correction device, where the device includes: a processing module; the processing module is configured to adjust the time delay of a first radio frequency signal of a first channel of a remote radio unit (RRU) according to a first time delay adjustment value to obtain a second radio frequency signal; the processing module is further configured to filter the second radio frequency signal through a correction filter to obtain a third radio frequency signal; where the first time delay adjustment value and the correction filter are determined based on a frequency-domain correction coefficient of the first channel of the RRU, and the frequency-domain correction coefficient is used to correct the amplitude and phase errors of the first channel.

[0015] The channel correction device provided in the embodiments of the present application determines a correction filter for each channel and a first time delay adjustment value for each channel based on the frequency-domain correction coefficients of each channel of the RRU, and adjusts the time delay and amplitude-phase errors of each channel based on the correction filter for each channel and the first time delay adjustment value for each channel. Therefore, it is possible to continuously adjust the phase and amplitude of the frequency-domain signal in a time-domain filtering convolution manner, avoiding the problem that the existing time-domain correction scheme can only rely on the time delay adjustment granularity supported by the hardware, and further improving the transmission performance of the channel.

[0016] In combination with the second aspect, in a possible implementation, the device further includes: an acquisition module; the acquisition module is configured to obtain the frequency-domain correction coefficient of the first channel of the RRU before performing time-delay adjustment on the first radio frequency signal of the first channel of the RRU according to the first time-delay adjustment value; the processing module is further configured to perform inverse fast Fourier transform (IFFT) processing on the frequency-domain correction coefficient obtained by the acquisition module to obtain a corresponding time-domain sampling sequence, the time-domain sampling sequence includes X sampling points, where X is a positive integer; the processing module is further configured to determine the first time-delay adjustment value and the correction filter based on the first sampling point among the X sampling points, and the first sampling point is the sampling point corresponding to the largest amplitude among the X sampling points.

[0017] In combination with the second aspect and the above possible implementation, in another possible implementation, the processing module is specifically configured to determine the first time-delay adjustment value according to a preset filter length and the index of the first sampling point in the time-domain sampling sequence, and the preset filter length is the filter length of the preset correction filter.

[0018] In combination with the second aspect and the above possible implementation, in another possible implementation, the processing module is specifically configured to determine the first filter coefficient according to the first L sample points and the last M sample points of the first sampling point, and generate the correction filter based on the first filter coefficient, where L is a positive integer less than or equal to X / 2, and M is a positive integer less than or equal to X / 2.

[0019] In combination with the second aspect and the above possible implementation, in another possible implementation, the frequency-domain correction coefficient includes at least one sample point;

[0020] Before performing IFFT processing on the frequency-domain correction coefficient, the processing module is further configured to copy and flip the first N sample points of the frequency-domain correction coefficient to obtain a first sample point sequence, and copy and flip the last N sample points of the frequency-domain correction coefficient to obtain a second sample point sequence, where N is a positive integer; the processing module is further configured to splice the first sample point sequence, the second sample point sequence and the at least one sample point to obtain a spliced frequency-domain correction coefficient; the processing module is specifically configured to perform IFFT processing on the spliced frequency-domain correction coefficient.

[0021] In combination with the second aspect and the above possible implementation, in another possible implementation, the processing module is specifically configured to splice the first sample point sequence to the starting position of the at least one sample point, and splice the second sample point sequence to the ending position of the at least one sample point to obtain a spliced frequency-domain correction coefficient.

[0022] Combined with the second aspect and the above possible implementation manners, in another possible implementation manner, the processing module is specifically configured to input the second radio frequency signal into the calibration filter for time domain convolution processing, and output the third radio frequency signal.

[0023] In a third aspect of the embodiments of the present application, an electronic device is provided, including a processor and a memory. The memory stores a program or instruction that can run on the processor. When the program or instruction is executed by the processor, the steps of the channel calibration method as described in the first aspect and the possible implementation manners of the first aspect are implemented.

[0024] In a fourth aspect of the embodiments of the present application, a readable storage medium is provided. A program or instruction is stored on the readable storage medium. When the program or instruction is executed by a processor, the steps of the channel calibration method as described in the first aspect and the possible implementation manners of the first aspect are implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a schematic flowchart of the channel calibration method provided by the embodiments of the present application;

[0027] Figure 2 It is a schematic diagram of the time domain sampling sequence after IFFT provided by the embodiments of the present application;

[0028] Figure 3 It is a schematic diagram of extending the frequency domain calibration coefficient provided by the embodiments of the present application;

[0029] Figure 4A It is a simulation diagram of the path loss value of the signal of the RRU channel provided by the embodiments of the present application;

[0030] Figure 4B It is a simulation diagram of the error vector magnitude of the signal of the RRU channel provided by the embodiments of the present application;

[0031] Figure 5 It is a schematic structural diagram of a channel calibration device provided by the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0033] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually of the same category, and the number of objects is not limited. For example, the first object can be one or more.

[0034] In addition, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0035] The terms "at least one (item)", "at least one of", etc. in the specification and claims of the present application refer to any one, any two or more combinations of the objects it contains. For example, at least one (item) of a, b, and c can represent: "a", "b", "c", "a and b", "a and c", "b and c", and "a, b, and c", where a, b, and c can be single or multiple. Similarly, "at least two (items)" means two or more, and its meaning is similar to that of "at least one (item)".

[0036] Next, some concepts and / or terms involved in the channel correction method provided in the embodiments of the present application will be explained.

[0037] 1. Multiple-Input Multiple-Output (MIMO) system

[0038] MIMO, also known as a multiple-input multiple-output system, refers to a structure that uses multiple antennas at both the transmitting end and the receiving end. This technology can double the capacity and spectrum utilization rate of a communication system without increasing the bandwidth, and is a key technology that must be adopted in the new generation of mobile communication systems.

[0039] 2. Channel

[0040] The channel refers to the RRU channel or the antenna channel of the antenna connected to the RRU. The RRU channel includes single-channel and multi-channel. The single-channel means that the ports of the RRU are connected to a total of one antenna, and the multi-channel means that multiple ports of the RRU are connected to multiple antennas. According to the signal transmission and reception types of the channel, the channel can be divided into a receiving channel and a transmitting channel.

[0041] 3. Sounding Reference Signal (SRS)

[0042] SRS is used to estimate the frequency-domain information of the uplink channel for frequency-selective scheduling and to estimate the uplink channel for downlink beamforming.

[0043] The following combines the accompanying drawings and details the channel calibration method provided by the embodiments of the present application through specific embodiments and their application scenarios.

[0044] For a TDD (Time-division Duplex) system, a major advantage is that it can be considered that the air interface channels of the uplink and downlink are reciprocal, that is Thus, the channel response of the corresponding downlink channel can be obtained through SRS (Sounding Reference Signal), and further non-codebook precoding is performed on the downlink PDSCH (Physical Downlink Shared Channel), greatly improving its performance.

[0045] However, in actual products, affected by multiple factors such as hardware, for the baseband, the obtained channel response is affected by hardware (or interference) in addition to the air interface channel, and there are certain deviations in the amplitude and phase of each antenna (reason). And since the antenna transmission and reception are not the same circuit, the amplitude and phase errors of transmission and reception of each antenna are different, that is, the channel response obtained by the baseband is:

[0046]

[0047]

[0048] Among them, is the air interface channel, E RX , E TX are the amplitude and phase deviations caused by each antenna, so there is H UL ≠(H DL ) T . At this time, when precoding is performed through SRS, the precoding gain cannot be obtained, and antenna calibration is required to calculate the antenna calibration coefficient so that:

[0049]

[0050] Meanwhile, in many scenarios, such as the scenario where radio frequency combining of antennas is required, channel calibration can only be performed on each channel in the time domain. At this time, how to calibrate the time offset and frequency selection characteristics of each channel becomes a problem.

[0051] The existing technical solution is to perform channel calibration through the linear fitting method. The existing method of performing channel calibration through the linear fitting method can only adjust the integer multiple of the time delay or only adjust the adjustment granularity supported by the hardware when adjusting the group time delay. Due to the limited adjustment granularity, the adjustment effect is limited, and the related technology ignores the frequency selection characteristics of the channel, resulting in a decrease in performance.

[0052] The channel calibration method provided by the embodiments of the present application determines a calibration filter and a first time delay adjustment value based on the frequency domain calibration coefficient of the first channel of the RRU. First, the time delay of the signal is adjusted by the first time delay adjustment value, and the phase and amplitude of the frequency domain signal are continuously adjusted by means of time domain filtering convolution for the signal after time delay adjustment, achieving the effect of adjusting the time delay and amplitude / phase, avoiding the problem that the existing time domain calibration scheme can only rely on the time delay adjustment granularity supported by the hardware, and calibrating the frequency selection characteristics of the device compared with the existing scheme through this calibration filter, thereby improving the calibration effect and further improving the transmission performance of the channel.

[0053] Figure 1 The flowchart of a channel calibration method provided by the embodiments of the present application is as Figure 1 shown. The channel calibration method may include the following steps S201 and S202:

[0054] Step S201: The channel calibration device adjusts the time delay of the first radio frequency signal of the first channel of the remote radio unit (RRU) according to the first time delay adjustment value to obtain a second radio frequency signal.

[0055] Wherein, the first time delay adjustment value is determined based on the frequency domain calibration coefficient of the first channel of the RRU.

[0056] Optionally, in the embodiments of the present application, the channel calibration device may perform an IFFT transform on the frequency domain calibration coefficient to convert it to the time domain, and determine the first time delay adjustment value based on the amplitude peak value of the sampling points in the time domain.

[0057] Optionally, in the embodiments of the present application, the first channel may be the signal transmission channel of the RRU of the first cell, or the first channel may be the signal reception channel of the RRU of the first cell.

[0058] Optionally, in the embodiments of the present application, the first channel may include multiple channels.

[0059] Exemplarily, there are two RRUs in cell 1, and the two RRUs form a DMIMO network. The two RRUs are RRU1 and RRU2 respectively. Both RRU1 and RRU2 have two antenna channels, and each antenna channel is used for receiving or transmitting radio frequency signals. Then, the above first channel may include the two antenna channels of RRU1 and the two antenna channels of RRU2.

[0060] Optionally, in the embodiment of the present application, the above first radio frequency signal may be a radio frequency signal transmitted through the first channel.

[0061] Optionally, in the embodiment of the present application, the above second radio frequency signal may be a radio frequency signal obtained by performing time delay adjustment on the first radio frequency signal and having a time delay less than a threshold.

[0062] Step S202: The channel correction device filters the second radio frequency signal through a correction filter to obtain a third radio frequency signal.

[0063] Among them, the above correction filter is determined based on the frequency domain correction coefficient of the first channel of the RRU.

[0064] Optionally, in the embodiment of the present application, the channel correction device may perform IFFT transformation on the above frequency domain correction coefficient to convert it to the time domain, and calculate the filter coefficient based on the amplitude / phase characteristics of the sampling points in the time domain, so as to obtain a correction filter.

[0065] Optionally, in the embodiment of the present application, the above correction filter is used to correct the amplitude error and phase error of the above first channel.

[0066] Optionally, in the embodiment of the present application, the channel correction device inputs the above second radio frequency signal into the correction filter for time domain convolution processing and outputs a third radio frequency signal.

[0067] Exemplarily, after inputting a radio frequency signal into the correction filter, perform time domain convolution operation (i.e., multiply and accumulate) on the coefficient of the correction filter and the radio frequency signal, and then output the processed radio frequency signal. In this way, by means of time domain filtering convolution, the amplitude and phase of the signal can be adjusted, so as to obtain a radio frequency signal whose amplitude / phase characteristics meet the requirements.

[0068] Exemplarily, taking the first time delay adjustment value as τ and the correction filter as f, first perform an integer multiple time delay adjustment of τ points on the signal to be corrected in the RRU channel to obtain an adjusted signal x′, and then correct the adjusted signal x′ using the calculated filter. The expression is as follows:

[0069]

[0070] Among them, x is the signal to be corrected, is the corrected signal, τ is the integer multiple time delay adjustment, f is the correction filter, and ⊙ represents the convolution operation.

[0071] It should be noted that in a multi-channel RRU, the inconsistent frequency responses caused by the phase and gain differences, aging, amplitude / phase characteristic distortion, etc. of a series of devices will all cause time-varying errors in the channels. In this way, there will be a large difference between the real channel and the ideal channel, affecting the overall performance of the system. Therefore, it is necessary to implement the channel correction function. In the embodiments of the present application, through channel correction, the channel delay and its amplitude / phase characteristics are tracked and compensated, so that its amplitude / phase characteristics tend to be consistent with those of the reference channel, reducing the channel error and meeting the accuracy requirements of the system.

[0072] The channel correction method provided by the embodiments of the present application determines the correction filter and the first time delay adjustment value of each channel based on the frequency domain correction coefficients of each channel of the RRU, and adjusts the time delay and amplitude-phase error of each channel based on the correction filter and the first time delay adjustment value of each channel. Thus, the phase and amplitude of the frequency domain signal can be continuously adjusted in the way of time domain filtering convolution, avoiding the problem that the existing time domain correction scheme can only rely on the time delay adjustment granularity supported by the hardware, and further improving the transmission performance of the channel.

[0073] Optionally, in the embodiments of the present application, before the above step S201, the channel correction method provided by the embodiments of the present application further includes the following steps S203 to S205:

[0074] Step S203: The channel correction device obtains the frequency domain correction coefficient of the first channel of the RRU.

[0075] Step S204: The channel correction device performs an inverse fast Fourier transform IFFT process on the above frequency domain correction coefficient to obtain the corresponding time domain sampling sequence.

[0076] Wherein, the above time domain sampling sequence includes X sampling points, and X is a positive integer.

[0077] Step S205: The channel correction device determines the first time delay adjustment value and the correction filter based on the first sampling point among the above X sampling points.

[0078] Wherein, the above first sampling point is the sampling point corresponding to the largest amplitude among the above X sampling points.

[0079] Optionally, in the embodiments of the present application, the channel correction device can obtain the frequency domain correction coefficient by sending a frequency domain correction sequence based on the LS algorithm or the Argos algorithm.

[0080] Exemplarily, assume that there are two RRU's for DMIMO networking, denoted as RRU1 and RRU2 respectively, and each RRU has two antenna channels. The calculation process of the frequency-domain correction coefficient is as follows: After RRU A sends a pilot signal and RRU B receives the pilot signal and performs channel estimation to obtain the channel response of the channel from RRU A to RRU B, RRU B sends a pilot signal, and after RRU A receives the pilot signal and performs channel estimation to obtain the channel response of the channel from RRU B to RRU A, then based on the channel response of the channel from RRU A to RRU B and the channel response of the channel from RRU B to RRU A, the correction value of the antenna of RRU A (i.e., the frequency-domain correction coefficient) and the correction value of the antenna of RRU B are calculated.

[0081] It should be noted that the specific process of obtaining the frequency-domain correction coefficient by sending a frequency-domain correction sequence can be referred to the description of the related technology, and the embodiments of the present application will not elaborate on this.

[0082] Optionally, in the embodiments of the present application, the channel correction device performs IFFT processing on the above frequency-domain correction coefficient to obtain a time-domain correction sequence corresponding to the frequency-domain correction coefficient. The expression for performing IFFT processing on the frequency-domain correction coefficient is as follows:

[0083]

[0084] where I is the result after IFFT, N IFFT represents the number of points of IFFT, and μ is the frequency-domain correction coefficient.

[0085] Optionally, in the embodiments of the present application, the above X sampling points correspond to X amplitudes.

[0086] Exemplarily, after performing IFFT on the frequency-domain correction coefficient, N-point complex numbers are obtained, and the modulus value of these complex numbers is the amplitude characteristic of the original signal at this delay value.

[0087] It should be noted that when performing IFFT processing, the input signal is the frequency-domain correction coefficient, and the output is the correction coefficient at each delay value.

[0088] Optionally, in the embodiments of the present application, the channel correction device can search for the amplitude peak of the X sampling points, determine the sampling point with the largest amplitude among the X sampling points (i.e., the first sampling point), and obtain the subscript (i.e., index) of this sampling point in the time-domain sampling sequence.

[0089] It can be understood that the subscript or index of the sampling point in the time-domain sampling sequence can represent the position of this sampling point in the entire sequence.

[0090] Optionally, in the embodiments of the present application, the channel correction device may calculate filter coefficients based on the amplitude and phase information of the above-mentioned first sampling point to obtain a correction filter.

[0091] Optionally, in the embodiments of the present application, the channel correction device may calculate a first time delay adjustment value based on the index of the above-mentioned first sampling point.

[0092] Optionally, in the embodiments of the present application, the process of determining the first time delay adjustment value based on the first sampling point among the above-mentioned X sampling points in step S204 may include the following step S204a:

[0093] Step S204a: The channel correction device determines the above-mentioned first time delay adjustment value according to the preset filter length and the index of the first sampling point in the above-mentioned time domain sampling sequence.

[0094] Wherein, the above-mentioned preset filter length is the filter length of the preset correction filter.

[0095] Optionally, in the embodiments of the present application, the above-mentioned preset filter length may be an empirical value, which is related to the correction performance and acceptable complexity, and can be obtained through simulation.

[0096] Exemplarily, the above-mentioned preset filter length may be 10.

[0097] Optionally, in the embodiments of the present application, the above-mentioned first time delay adjustment value may be an integer.

[0098] Optionally, in the embodiments of the present application, after obtaining the time domain correction sequence, the channel correction device searches for the sampling point with the largest amplitude among the X sampling points of the time domain correction sequence, and calculates the above-mentioned first time delay adjustment value according to the index of the sampling point and the preset filter length.

[0099] Exemplarily, after obtaining the time domain sampling sequence I, search for the peak value of I, where the subscript corresponding to the largest peak is IDX. Further, when IDX is less than half of the number of points of the IFFT, the difference between IDX and half of the preset filter length is used as the first time delay adjustment value; or, when IDX is greater than half of the number of points of the IFFT, the difference between IDX, the number of points of the IFFT, and half of the preset filter length is used as the first time delay adjustment value, and the calculation formula is as follows:

[0100]

[0101] Wherein, N IFFT is the number of points of the IFFT, N fliterLen is the filter length, and τ is the first time delay adjustment value.

[0102] Optionally, in the embodiments of the present application, the process of determining the correction filter based on the first sampling point among the above X sampling points in step S204 may include the following step S204b:

[0103] Step S204b: The channel correction device determines the first filter coefficient according to the first L sample value points and the last M sample value points of the above first sampling point, and generates the above correction filter based on the first filter coefficient.

[0104] Wherein, L is a positive integer less than or equal to X / 2, and M is a positive integer less than or equal to X / 2.

[0105] Optionally, in the embodiments of the present application, the number of the above L sample value points and M sample value points is determined according to a preset filter length. Optionally, L and M are less than or equal to the preset filter length.

[0106] Exemplarily, the preset filter length N fliterLen is 10, then the L sample value points and the M sample value points in total include 10 sampling points. For example, the L sample value points and the M sample value points may respectively include 5 sample value points, or the L sample value points may include 7 sample value points and the M sample value points may include 3 sample value points, or the L sample value points may include 3 sample value points and the M sample value points may include 7 sample value points.

[0107] It should be noted that the number of the L sample value points and the M sample value points listed in the above embodiments is only a possible example, and the number of sample value points can be specifically set according to actual needs, and the embodiments of the present application do not limit this.

[0108] Exemplarily, Figure 2 is a schematic diagram of the time-domain sampling sequence after IFFT provided by the embodiments of the present application. Figure 2 The horizontal axis of Figure 2 shows the index of the sampling point, Figure 2 shows 150 sampling points, and the corresponding index range is 0-150. The vertical axis represents the amplitude corresponding to the sampling point. As

[0109] It should be noted that Figure 2 the sampling points in the solid line box are the selected first L sample value points and the last M sample value points.

[0110] Exemplarily, after obtaining the time-domain sampling sequence I, according to the searched amplitude peak, a total of N on both sides of the peak are taken fliterLenThe data is used as the filter coefficient of the correction filter, and the calculation formula is as follows:

[0111]

[0112] Where I is the IFFT result, IDX is the subscript corresponding to the maximum peak of |I|, and N fliterLen is the filter length, f is the correction filter, Indicates rounding down. Indicates rounding up.

[0113] Optionally, in an embodiment of the present application, the frequency domain correction coefficient includes at least one sampling point; before the above step S204, the channel correction method provided in the embodiment of the present application further includes the following steps S206 and S207:

[0114] Step S206: the channel correction device copies and flips the first N sample points of the frequency domain correction coefficient to obtain a first sample point sequence, and copies and flips the last N sample points of the frequency domain correction coefficient to obtain a second sample point sequence.

[0115] Wherein, N is a positive integer.

[0116] Step S207: the channel correction device splices the first sample point sequence, the second sample point sequence and at least one sample point to obtain a spliced ​​frequency domain correction coefficient.

[0117] In combination with the above step S206 and step S207, the process of performing IFFT processing on the frequency domain correction coefficient in the above step S204 may include the following steps S204a:

[0118] Step S204a: the channel correction device performs IFFT processing on the above-mentioned spliced ​​frequency domain correction coefficients.

[0119] Figure 3 A schematic diagram of extending the frequency domain correction coefficient provided in an embodiment of the present application, such as Figure 3 As shown, the length of the frequency domain correction sequence (i.e., the frequency domain correction coefficient) is N after the first N sample points are copied and flipped. ext The sample point sequence of is spliced ​​before the first sample point of the original frequency domain correction sequence, and the length of the frequency domain correction sequence (i.e., the frequency domain correction coefficient) is obtained by copying and flipping the last N sample points. ext The sampling point sequence is spliced ​​after the last sampling point of the original frequency domain correction sequence to obtain a spliced ​​frequency domain correction sequence, thereby realizing the extension of the frequency domain correction coefficient.

[0120] For example, in combination with the above Figure 3 , the frequency domain correction coefficient is extended, and the calculation formula is as follows:

[0121]

[0122]

[0123] Among them, is the first sample value point sequence, is the second sample value point sequence, μ(1:N ext ) represents intercepting the first sample value point to the N ext th sample value points of the signal, N ext is the extension length (i.e., the length of the first N sample value points), and flip(.) represents flipping the signal, that is, the first point of the signal becomes the last point, and the last point becomes the first point.

[0124] Among them, μ(N μ -N ext +1:N μ ) represents intercepting the (N μ -N ext +1)th to the N μ th sample value points of the signal, that is, the last N ext sample value points of μ, and flip(.) represents flipping the signal.

[0125]

[0126] Among them, is the frequency domain correction sequence before extension, that is, the frequency domain correction coefficient.

[0127] It should be noted that N ext does not exceed N μ , and the longer the better.

[0128] In the embodiments of the present application, by extending the frequency domain correction coefficient, the Gibbs effect caused by truncation can be reduced, so that signal discontinuity or sudden step can be avoided.

[0129] Exemplarily, taking the frequency domain correction sequence including 100 sample value points as an example, when extending the frequency domain correction sequence, the first 30 sample value points of the frequency domain correction sequence are copied, and the order of these 30 sample value points is flipped to obtain the sample value points to be spliced (i.e., the first sample value point sequence), and, the last 30 sample value points of the frequency domain correction sequence are copied, and the order of the last 30 sample value points is flipped to obtain the sample value points to be spliced (i.e., the second sample value point sequence), then the first sample value point sequence is spliced before the first sample value point of the original frequency domain correction sequence, and the second sample value point sequence is spliced after the last sample value point of the original frequency domain correction sequence to obtain the spliced frequency domain correction sequence, thereby realizing the extension of the frequency domain correction coefficient.

[0130] It should be noted that the flipping of the above sample value point sequence refers to flipping the order of the sample value points in the sample value point sequence, so that after flipping, the first sample value point of the 30 sample value points becomes the last sample value point, and the last sample value point of the 30 sample value points becomes the first sample value point.

[0131] In the embodiment of the present application, by intercepting the first 30 sample value point sequences and the last 30 sample value point sequences of the frequency domain correction sequence, and splicing the intercepted sequences with the frequency domain correction sequence after flipping, the extension of the frequency domain correction sequence is realized, so that the Gibbs effect caused by truncation can be reduced, and the time domain sampling points obtained after the frequency domain correction sequence is converted from the frequency domain to the time domain are not easily distorted.

[0132] Figure 4A It is a schematic diagram of the path loss value of the signal of the RRU channel provided by the embodiment of the present application. Figure 4B It is a schematic diagram of the error vector magnitude provided by the embodiment of the present application. Figure 4A and Figure 4B show the performance impact on the downlink physical control channel PDSCH after calibration using the calibration filter provided by the embodiment of the present application and the linear fitting scheme. Among them, the filter generated by the present application is set to 10th order. The remaining parameters are set as shown in the following table:

[0133] Channel TDL-A Modulation method 256QAM Number of streams 4 Number of OFDM symbols 14 Number of transmitting antennas 8 Number of receiving antennas 4

[0134] As Figure 4A and Figure 4B shown, after calibrating the radio frequency signal of the antenna through the 10th order calibration filter provided by the embodiment of the present application, both the path loss value (i.e., BLER) and the error vector magnitude (i.e., EVM) are significantly reduced and close to the ideal reciprocal situation. After calibrating the RRU channel through the first delay adjustment value and the calibration filter of the embodiment of the present application, compared with the first order filter scheme of linear fitting, there is a performance gain of 1.5 dB. Therefore, the channel calibration method provided by the embodiment of the present application has a higher gain compared with the linear fitting method in the related art.

[0135] The above mainly introduces the solution provided by the embodiments of the present application from the perspective of the channel correction device. It can be understood that in order to implement the above functions, the channel correction device includes the corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should easily realize that, combining the algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in the way of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0136] The embodiments of the present application can divide the functional modules of the channel correction device according to the above method examples. For example, each functional module can be divided corresponding to each function, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware or in the form of a software functional module. It should be noted that the division of modules in the embodiments of the present application is illustrative, only a logical function division, and there can be other division methods in actual implementation.

[0137] In the case of dividing each functional module corresponding to each function, Figure 5 shows a possible composition schematic diagram of the channel correction device involved in the above embodiments. As Figure 5 shown, the channel correction device 500 may include: a processing module 501; wherein, the above processing module 501 is used to adjust the time delay of the first radio frequency signal of the first channel of the remote radio unit (RRU) according to the first time delay adjustment value to obtain a second radio frequency signal; the above processing module 501 is further used to filter the second radio frequency signal through a correction filter to obtain a third radio frequency signal; wherein, the above first time delay adjustment value is determined based on the frequency domain correction coefficient of the first channel of the RRU of the above correction filter, and the frequency domain correction coefficient is used to correct the amplitude and phase errors of the first channel.

[0138] Optionally, in the embodiments of the present application, the above device further includes: an acquisition module; the acquisition module is used to acquire the frequency domain correction coefficient of the first channel of the RRU before adjusting the time delay of the first radio frequency signal of the first channel of the RRU according to the first time delay adjustment value; the above processing module is further used to perform inverse fast Fourier transform (IFFT) processing on the frequency domain correction coefficient acquired by the acquisition module to obtain a corresponding time domain sampling sequence, the time domain sampling sequence includes X sampling points, and X is a positive integer; the above processing module is further used to determine the first time delay adjustment value and the correction filter based on the first sampling point among the X sampling points, and the first sampling point is the sampling point corresponding to the largest amplitude among the X sampling points.

[0139] Optionally, in the embodiments of the present application, the processing module is specifically configured to determine a first delay adjustment value according to a preset filter length and an index of the first sampling point in the time-domain sampling sequence, where the preset filter length is the filter length of the preset calibration filter.

[0140] Optionally, in the embodiments of the present application, the processing module is specifically configured to determine first filter coefficients according to the first L sample value points and the last M sample value points of the first sampling point, and generate a calibration filter based on the first filter coefficients, where M is a positive integer less than or equal to X / 2, and L is a positive integer less than or equal to X / 2.

[0141] Optionally, in the embodiments of the present application, the frequency-domain calibration coefficient includes at least one sample value point;

[0142] Before performing IFFT processing on the frequency-domain calibration coefficient, the processing module is further configured to copy and flip the first N sample value points of the frequency-domain calibration coefficient to obtain a first sample value point sequence, and copy and flip the last N sample value points of the frequency-domain calibration coefficient to obtain a second sample value point sequence, where N is a positive integer; the processing module is further configured to splice the first sample value point sequence, the second sample value point sequence, and at least one sample value point to obtain a spliced frequency-domain calibration coefficient; the processing module is specifically configured to perform IFFT processing on the spliced frequency-domain calibration coefficient.

[0143] Optionally, in the embodiments of the present application, the processing module is specifically configured to splice the first sample value point sequence to the starting position of the at least one sample value point, and splice the second sample value point sequence to the ending position of the at least one sample value point to obtain a spliced frequency-domain calibration coefficient.

[0144] Optionally, in the embodiments of the present application, the processing module is specifically configured to input the second radio frequency signal into the calibration filter for time-domain convolution processing, and output the third radio frequency signal.

[0145] The channel calibration device provided by the embodiments of the present application determines calibration filters and first delay adjustment values of each channel based on the frequency-domain calibration coefficients of each channel of the RRU, and adjusts the delay and amplitude-phase error of each channel based on the calibration filters and the first delay adjustment values of each channel. Therefore, the phase and amplitude of the frequency-domain signal can be continuously adjusted by means of time-domain filtering convolution, avoiding the problem that the existing time-domain calibration scheme can only rely on the delay adjustment granularity supported by the hardware, and further improving the transmission performance of the channel.

[0146] It should be noted that all relevant content of each step involved in the above method embodiments can be cited in the function descriptions of the corresponding functional modules, and will not be elaborated here.

[0147] An embodiment of the present application provides an electronic device, which is characterized by including a processor and a memory. The memory stores a program or instruction that can run on the processor. When the program or instruction is executed by the processor, the steps of the channel correction method in the above embodiments are implemented.

[0148] It should be noted that the specific working processes of each functional module in the electronic device provided in the embodiments of the present application can refer to the specific descriptions of the corresponding processes in the method embodiments, and will not be elaborated in detail here. The electronic device provided in the embodiments of the present application is used to execute the above channel correction method, and thus can achieve the same effect as the above channel correction method.

[0149] An embodiment of the present application provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the channel correction method as described above are implemented.

[0150] Through the description of the above embodiments, those skilled in the art can clearly understand that for the convenience and brevity of description, only the above division of each functional module is used as an example. In actual applications, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

[0151] In several embodiments provided by the present application, it should be understood that the disclosed device and method can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the module or unit is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0152] The unit described as a separated component may or may not be physically separated. The component displayed as a unit may be a physical unit or multiple physical units, that is, it can be located in one place, or can be distributed to multiple different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0153] In addition, in each embodiment of the present application, each functional unit may be integrated into a processing unit, may exist separately as individual physical units, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of a software functional unit.

[0154] An embodiment of the present application provides a readable storage medium, characterized in that a program or instructions are stored on the readable storage medium, and when the program or instructions are executed by a processor, the steps of the channel correction method as described in the above embodiment are implemented.

[0155] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a readable storage medium. Based on such an understanding, the technical solution of the embodiment of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, may be embodied in the form of a software product. The software product is stored in a storage medium and includes several instructions for causing a device (which may be a single-chip microcomputer, a 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: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc.

[0156] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present application, and all of them should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A channel correction method, characterized in that, the method includes: performing delay adjustment on a first radio frequency signal of a first channel of a remote radio unit (RRU) according to a first delay adjustment value to obtain a second radio frequency signal; performing filtering processing on the second radio frequency signal through a correction filter to obtain a third radio frequency signal; wherein, the first delay adjustment value is determined based on a frequency domain correction coefficient of the first channel of the RRU, and the frequency domain correction coefficient is used to correct amplitude error and phase error of the first channel.

2. The method according to claim 1, characterized in that, before performing delay adjustment on the first radio frequency signal of the first channel of the RRU according to the first delay adjustment value, the method further includes: acquiring a frequency domain correction coefficient of the first channel of the RRU; performing inverse fast Fourier transform (IFFT) processing on the frequency domain correction coefficient to obtain a corresponding time domain sampling sequence, the time domain sampling sequence includes X sampling points, and X is a positive integer; determining the first delay adjustment value and the correction filter based on a first sampling point among the X sampling points, and the first sampling point is the sampling point with the largest amplitude among the X sampling points.

3. The method according to claim 2, characterized in that, determining the first delay adjustment value based on the first sampling point among the X sampling points includes: determining the first delay adjustment value according to a preset filter length and an index of the first sampling point in the time domain sampling sequence, and the preset filter length is the filter length of the preset correction filter.

4. The method according to claim 2, characterized in that, determining the correction filter based on the first sampling point among the X sampling points includes: determining first filter coefficients according to the first L sample value points and the subsequent M sample value points of the first sampling point, and generating the correction filter based on the first filter coefficients, where L is a positive integer less than or equal to X / 2, and M is a positive integer less than or equal to X / 2.

5. The method according to claim 2, characterized in that, the frequency domain correction coefficient includes at least one sample value point; before performing IFFT processing on the frequency domain correction coefficient, the method further includes: copying and flipping the first N sample value points of the frequency domain correction coefficient to obtain a first sample value point sequence, and copying and flipping the subsequent N sample value points of the frequency domain correction coefficient to obtain a second sample value point sequence, where N is a positive integer; concatenating the first sample value point sequence, the second sample value point sequence and the at least one sample value point to obtain a concatenated frequency domain correction coefficient; performing IFFT processing on the frequency domain correction coefficient includes: performing IFFT processing on the concatenated frequency domain correction coefficient.

6. The method according to claim 5, characterized in that, concatenating the first sample value point sequence, the second sample value point sequence and the at least one sample value point to obtain a concatenated frequency domain correction coefficient includes: Concatenate the first sample value point sequence to the starting position of the at least one sample value point, and concatenate the second sample value point sequence to the ending position of the at least one sample value point to obtain the concatenated frequency domain correction coefficient.

7. The method according to claim 1, wherein, the filtering the second radio frequency signal through a correction filter to obtain a third radio frequency signal includes: inputting the second radio frequency signal into the correction filter for time domain convolution processing, and outputting the third radio frequency signal.

8. A channel correction device, wherein, the device includes: a processing module; the processing module is configured to adjust the time delay of the first radio frequency signal of the first channel of the remote radio unit (RRU) according to a first time delay adjustment value to obtain a second radio frequency signal; the processing module is further configured to filter the second radio frequency signal through a correction filter to obtain a third radio frequency signal; wherein, the first time delay adjustment value is determined based on the frequency domain correction coefficient of the first channel of the RRU by the correction filter, and the frequency domain correction coefficient is used to correct the amplitude and phase errors of the first channel.

9. An electronic device, wherein, it includes a processor and a memory, the memory stores a program or instruction that can run on the processor, and when the program or instruction is executed by the processor, the steps of the channel correction method according to any one of claims 1 to 7 are implemented.

10. A readable storage medium, wherein, the readable storage medium stores a program or instruction, and when the program or instruction is executed by a processor, the steps of the channel correction method according to any one of claims 1 to 7 are implemented.

Images