WO2020132893A1 - Pim cancellation method and device - Google Patents

Abstract

The present application discloses a passive inter modulation (PIM) cancellation device and method, relating to the field of radio frequency and used to perform PIM cancellation in a multiple transmission and multiple receiving channel scenario. The PIM cancellation device comprises: a first acquisition unit used to acquire digital intermediate-frequency signals of M transmission channels; a second acquisition unit used to acquire received signals of N receiving channels, wherein the received signal comprises a PIM signal, and the PIM signal is generated by means of the digital intermediate-frequency signals of the M transmission channels; an analog unit connected to the first acquisition unit and used to acquire N PIM cancellation signals according to the digital intermediate-frequency signals of the M transmission channels; a cancellation unit connected to the second acquisition unit and the analog unit and used to acquire N cancellation result signals according to the received signal and the N PIM cancellation signals; and an adjustment unit connected to the cancellation unit and the analog unit and used to adjust a filter coefficient of a first filtering and a coefficient of nonlinear processing according to the N cancellation result signals, such that the filter coefficient of the first filtering and the coefficient of the nonlinear processing converge.

Description

PIM cancellation method and device Technical field

This application relates to the field of radio frequency, and in particular to a PIM cancellation method and device.

Background technique

In a multi-carrier base station communication system of frequency division duplex (FDD) format, in a multi-carrier, large transmission bandwidth scenario, the antenna feeder system will generate passive intermodulation due to bad parts, loose screws, vibration, etc. (passive intermodulation, PIM) signal, when the PIM signal falls into the frequency band of the received signal, it will coincide with the spectrum of the received signal, affecting the sensitivity of the receiving channel, and thus affecting the upstream throughput rate.

As shown in FIG. 1, it is a schematic diagram of the principle of single input single antenna PIM signal cancellation in the prior art. In the transmit channel, the baseband signal in the digital domain passes through the rate of rise and frequency shift 101 to obtain a digital intermediate frequency signal, which is multi-carrier combined. In the channel-level link, it passes through a digital-to-analog converter (DAC) 102. It enters the analog transmission channel 103, and then is filtered by the transmission filter 104 and then transmitted to the space through the antenna 105. In the receiving channel, the received signal is filtered by the receiving filter 106 after receiving through the antenna 105, and enters the analog domain receiving channel 107, after analog-to-digital conversion (ADC) 108, and then through frequency shift and down rate 109, to obtain Received signal in the digital domain.

If the PIM fault point exists in the intermediate radio frequency conduction link (that is, between the transmission filter 104/reception filter 106 and the antenna 105), the PIM canceller 100 obtains the digital intermediate frequency signal from the transmission channel and generates a PIM cancellation signal, After receiving the PIM-containing received signal from ADC 108 in the receiving channel, and subtracting the PIM-containing received signal from the PIM canceled signal, the PIM-free received signal can be obtained to realize the PIM canceled.

However, with the development of communication technology, the number of transmitting channels and receiving channels has gradually increased, and multiple input multiple output (multiple input multiple output (MIMO)) antenna systems have become mainstream. As shown in Figure 2, in the scenario of multiple transmit and multiple receive channels, there are multiple antenna radiated PIM signals, that is, PIM failure points not only exist in the middle RF conductive link, but may also exist in the space electromagnetic field of the antenna radiation range. The nonlinear intermodulation generated at the PIM fault point will be received by all antennas, affecting the sensitivity of all receiving channels.

At this time, the multi-antenna radiated PIM signal cannot be cancelled by the single input single antenna PIM cancellation principle shown in FIG. 1.

Summary of the invention

Embodiments of the present application provide a PIM cancellation method and device, which are used to implement PIM cancellation in a scenario of multiple transmission and multiple reception channels.

To achieve the above purpose, the embodiments of the present application adopt the following technical solutions:

In a first aspect, a passive intermodulation PIM cancellation device is provided, including: a first acquisition unit for acquiring digital intermediate frequency signals of M transmission channels, where M is an integer greater than 1; a second acquisition unit, It is used to acquire the received signals of N receiving channels, wherein the received signals include PIM signals, which are generated by the digital intermediate frequency signals of M transmitting channels, and N is an integer greater than 1; the analog unit is connected to the first acquiring unit, It is used to obtain N PIM cancellation signals according to the digital intermediate frequency signals of M transmission channels, wherein the N PIM cancellation signals are used to cancel the PIM signal in the received signal, and the analog unit includes a first linear module and a nonlinear module connected in series , The first linear module is used to perform first filtering and first linear superposition on the digital intermediate frequency signals of M transmission channels to obtain P first linear superposition results, and the nonlinear module is used to perform the P first linear superposition results Perform nonlinear processing separately to obtain the results of P nonlinear processing. The results of P nonlinear processing are used to generate or serve as N PIM cancellation signals, P is a positive integer; the cancellation unit, and the second acquisition unit and simulation The unit is connected to obtain N cancellation result signals according to the received signal and N PIM cancellation signals; the adjustment unit is connected to the cancellation unit and the analog unit to adjust the first filter according to the N cancellation result signals Filter coefficients and non-linear processing coefficients, so that the first filter coefficients and non-linear processing coefficients converge. The PIM cancellation device obtains digital intermediate frequency signals of M transmission channels, where M is an integer greater than 1. According to the digital intermediate frequency signals of the M transmission channels, N PIM cancellation signals are obtained, and N is an integer greater than 1. In the process of obtaining N PIM cancellation signals based on the digital intermediate frequency signals of the M digital intermediate frequency channels, the digital intermediate frequency signals of the M transmission channels are successively filtered, linearly superimposed, and nonlinearly processed. Obtain received signals containing PIM signals from N receiving channels. The N received signals and the N PIM cancellation signals are respectively differentiated to obtain N cancellation result signals. The cancellation result signal represents the error between the received signal and the PIM cancellation signal. By continuously adjusting the filter coefficients of the filter and the coefficients of nonlinear processing, the mean square of the error is gradually reduced. With the increase of time, the filtered filter coefficients and nonlinear processing coefficients tend to be stable, the mean square of the error tends to be minimum, the filtered filter coefficients and nonlinear processing coefficients converge, and the cancellation result signal at this time is no PIM received signals or received signals containing a small amount of PIM signals. Therefore, the PIM cancellation device realizes PIM cancellation in the scenario of multiple transmission and multiple reception channels.

In a possible implementation manner, the first acquiring unit is specifically configured to: acquire the baseband signals of the M transmission channels; perform the rate-up and frequency shift on the baseband signals to obtain the digital intermediate frequency signals of the M transmission channels. This embodiment provides a way to obtain digital intermediate frequency signals of M transmission channels.

In a possible implementation manner, the first acquiring unit is specifically configured to: acquire the radio frequency signal between the transmit filter and the antenna in the M transmit channels; perform analog-to-digital conversion, frequency shift, and rate reduction on the radio frequency signal to obtain M Digital IF signal for each transmission channel. This embodiment provides another way of acquiring digital intermediate frequency signals of M transmission channels.

In a possible implementation manner, the first acquiring unit is specifically configured to: acquire the radio frequency signal between the power amplifier and the transmit filter in the M transmission channels; perform analog-to-digital conversion, frequency shift, and rate reduction on the radio frequency signal to obtain M Digital IF signal for each transmission channel. This embodiment provides another way of acquiring digital intermediate frequency signals of M transmission channels.

In a possible implementation manner, the first acquiring unit is specifically configured to: acquire the radio frequency signal radiated into the space through the antenna; perform analog-to-digital conversion, frequency shift, and rate reduction on the radio frequency signal to obtain the digital intermediate frequency of the M transmission channels signal. This embodiment provides another way of acquiring digital intermediate frequency signals of M transmission channels.

In a possible implementation manner, the first linear module includes P first linear submodules; wherein each linear submodule in the P first linear submodules is specifically used for digital intermediate frequency of M transmission channels The signals are first filtered to obtain M first filtered results, and the first linear superposition is performed on the M first filtered results to obtain a first linear superposed result; wherein each first linear submodule includes A first linear adder and M first filters, each of the M first filters is used to perform a first filtering on the digital intermediate frequency signal of a transmission channel to obtain a first filtering result, the first The linear adder is used to perform a first linear superposition on the M first filtered results to obtain a first linear superimposed result. Because the digital IF signals of the M transmission channels are transmitted to the space through the antenna and then aggregated at the PIM fault point, this process can be regarded as a linear superposition process of the digital IF signals of the M transmission channels in the space. Therefore, the first linear module can be used to simulate the linear superposition process of the digital intermediate frequency signals of the M transmission channels in space.

In a possible implementation manner, the non-linear module includes P non-linear sub-modules, and each non-linear sub-module is used to perform non-linear processing on one of the P first linear superposition results to obtain a non-linear processing the result of. Because the digital intermediate frequency signals of the M transmission channels are transmitted to the space through the antenna and aggregated at the PIM fault point, a multi-antenna radiated PIM signal is formed, and the multi-antenna radiated PIM signal is received by the N receiving channels through different paths. Multi-antenna radiated PIM signals include nonlinear components. Therefore, the non-linear module is used to simulate the process of linearly superimposing the digital intermediate frequency signals of M transmission channels in space and exciting the PIM signal.

In a possible implementation manner, the simulation unit further includes a second linear module connected in series after the nonlinear module. The second linear module is used to perform a second filter on the results of the P nonlinear processes to obtain N PIM cancellations. Signal; wherein, the second linear module includes N second linear sub-modules, and each of the second linear sub-modules of the N second linear sub-modules is specifically used to perform a second filtering on the results of P nonlinear processing to obtain Results of P second filters; where each second linear sub-module includes P second filters, each of the P second filters is used for the results of P nonlinear processing One performs second filtering to obtain a second filtering result; the adjusting unit is also used to adjust the filtering coefficient of the second filtering according to the N cancellation result signals, so that the filtering coefficient of the second filtering converges. The second linear module can compensate the unevenness of the group delay introduced by the receiving channel and the receiving filter, and has the effect of improving the correction performance for broadband scenes.

In a possible implementation manner, P is greater than 1, and the second linear submodule further includes a second linear adder, and the second linear adder is used to perform a second linear addition on the results of the P second filtering to obtain a PIM Cancel the signal. When the number of the second filters is more than one, the second linear adder may linearly superimpose the results of the second filtering on the P second filters in the same second linear sub-module to obtain a PIM cancellation signal.

In a possible implementation manner, the second filter is a finite impulse response FIR filter or an infinite impulse response IIR filter. This embodiment provides a possible implementation form of the second filter.

In a possible implementation manner, the first filter is a FIR filter or an IIR filter. This embodiment provides a possible implementation form of the first filter. It can be used to simulate the memory characteristics of the space radiation process and the physical processes such as standing wave and reflection.

In a second aspect, a passive intermodulation PIM cancellation method is provided, which includes: acquiring digital intermediate frequency signals of M transmission channels, where M is an integer greater than 1, and acquiring received signals of N receiving channels, wherein, receiving The signal includes a PIM signal, which is generated by the digital intermediate frequency signals of M transmission channels, and N is an integer greater than 1; according to the digital intermediate frequency signals of M transmission channels, N PIM cancellation signals are obtained, among which, N PIM cancellation signals It is used to cancel the PIM signal in the received signal, and obtain N PIM cancellation signals according to the digital intermediate frequency signals of M transmission channels. The method includes: performing first filtering and first linear superposition on the digital intermediate frequency signals of M transmission channels to obtain P The result of the first linear superposition is to perform nonlinear processing on the results of the P first linear superpositions respectively to obtain the results of P nonlinear processing, and the results of the P nonlinear processing are used to generate or serve as N PIM cancellation signals, P is a positive integer; according to the received signal and N PIM cancellation signals to obtain N cancellation result signals; according to the N cancellation result signals, the filter coefficients of the first filter and the coefficients of the non-linear processing are adjusted to filter the first filter Coefficients and coefficients of nonlinear processing converge.

According to a third aspect, there is provided a computer-readable storage medium storing one or more programs, the one or more programs including instructions, which when executed by a computer causes the computer to execute as described in the second aspect PIM cancellation method.

According to a fourth aspect, there is provided a computer program product containing instructions, which when executed on a computer, causes the computer to execute the PIM cancellation method as described in the second aspect.

According to a fifth aspect, there is provided a PIM cancellation device, including: a processor and a memory, where the memory is used to store a program, and the processor calls the program stored in the memory to execute the PIM cancellation method described in the second aspect.

For the technical effects of the second aspect to the fifth aspect, reference may be made to the content of the first aspect and various possible implementation manners of the first aspect.

BRIEF DESCRIPTION

FIG. 1 is a schematic diagram of a single input single antenna PIM cancellation principle in the prior art;

2 is a schematic diagram of a multi-antenna radiating PIM scenario provided by an embodiment of this application;

FIG. 3 is a schematic diagram of a multi-antenna conduction PIM scenario provided by an embodiment of this application;

4 is a schematic diagram of a multi-antenna conduction and multi-antenna radiating PIM scenario provided by an embodiment of this application;

5 is a schematic diagram 1 of a method for acquiring a digital intermediate frequency signal provided by an embodiment of the present application;

6 is a schematic diagram 2 of a method for acquiring a digital intermediate frequency signal provided by an embodiment of the present application;

7 is a schematic diagram 3 of a method for acquiring a digital intermediate frequency signal provided by an embodiment of the present application;

8 is a schematic diagram 4 of a method for acquiring a digital intermediate frequency signal provided by an embodiment of the present application;

9 is a schematic diagram 5 of a method for acquiring a digital intermediate frequency signal provided by an embodiment of the present application;

10 is a schematic structural diagram of a PIM cancellation device according to an embodiment of this application;

11 is a schematic flowchart of a PIM cancellation method provided by an embodiment of the present application;

12 is a schematic structural diagram 1 of a simulation unit provided by an embodiment of the present application;

13 is a second schematic structural diagram of a simulation unit provided by an embodiment of the present application.

detailed description

The PIM cancellation device and method provided in the embodiments of the present application can be applied to different communication systems, for example, can be applied to a multi-carrier base station communication system of FDD format. According to the different communication protocols adopted by the communication system, for example, the first 4th generation (4G) communication protocol, 5th generation (5G) communication protocol, etc. The PIM cancellation device can refer to base station, evolved node B (evolved node B, eNB), gNB, etc. limited.

The PIM cancellation device and method provided in the embodiments of the present application can be used in a scenario of multiple transmission and multiple reception channels to obtain digital intermediate frequency signals of M transmission channels, where M is an integer greater than 1. According to the digital intermediate frequency signals of the M transmission channels, N PIM cancellation signals are obtained, and N is an integer greater than 1. In the process of obtaining N PIM cancellation signals based on the digital intermediate frequency signals of the M digital intermediate frequency channels, the digital intermediate frequency signals of the M transmission channels are successively filtered, linearly superimposed, and nonlinearly processed. Obtain received signals containing PIM signals from N receiving channels. The N received signals and the N PIM cancellation signals are respectively differentiated to obtain N cancellation result signals. The cancellation result signal represents the error between the received signal and the PIM cancellation signal. By continuously adjusting the filter coefficients of the filter and the coefficients of nonlinear processing, the mean square of the error is gradually reduced. With the increase of time, the filtered filter coefficients and nonlinear processing coefficients tend to be stable, the mean square of the error tends to be minimum, the filtered filter coefficients and nonlinear processing coefficients converge, and the cancellation result signal at this time is no PIM received signals or received signals containing a small amount of PIM signals.

The PIM cancellation device and method provided in the embodiments of the present application can be applied not only to the multi-antenna radiating PIM scenario shown in FIG. 2 and the multi-antenna conductive PIM scenario shown in FIG. 3, but also to the 4 shows a multi-antenna conduction multi-antenna radiation compound PIM scenario.

The multi-antenna radiated PIM scene refers to: PIM signals are generated in the surrounding space field inside or outside the antenna array, and are subjected to multiplexing, PIM signal excitation, and PIM signal conduction in the form of electromagnetic waves.

In a multi-antenna system, the digital intermediate frequency signal of the transmission channel is transmitted into the space field through the antenna. If there is a PIM fault somewhere in the space field, the multi-antenna radiated PIM signal is excited.

The multi-antenna conduction PIM scenario refers to: the PIM signal is generated in the transmission conduction path before the antenna air interface or somewhere in the reception conduction path after the antenna air interface. Unlike the multi-antenna radiating PIM scenario, the multi-antenna conductive PIM signal generation And transmission depends on the actual transmission path, therefore, the multi-antenna conductive PIM signal is mostly present in the transmission filter, the reception filter and the welding joints of the interconnection joints are corroded somewhere.

According to the actual physical characteristics, the multi-antenna conductive PIM signal is usually only related to the digital intermediate frequency signal of a single transmission channel. At this time, the linear superposition using the traditional PIM canceller can achieve cancellation. However, considering that in a multi-antenna system, the isolation in each transmission channel is poor, the multi-antenna conductive PIM signals will leak to each other between the transmission channels, forming a multi-antenna conductive PIM signal. At this time, the performance of the traditional PIM canceller will be greatly affected.

The multi-antenna conduction multi-antenna radiating PIM scenario is a superposition of the multi-antenna radiating PIM scenario and the multi-antenna conducting PIM scenario, which will not be repeated here.

First, the PIM cancellation principle in the scenario of a single-transmission and single-reception channel in a medium-frequency radio link will be described.

Based on the theory of radio frequency communication, in the scenario of single transmission and single reception channel, the baseband signal of a single frequency band undergoes frequency shift, and the digital intermediate frequency signal of a transmission channel is:

Among them, e is the exponential function, ω is the carrier frequency, n is the time variable, and x is the baseband signal corresponding to a certain radio frequency band.

If the function NL(|x(n)|) is defined as the non-linear component of the PIM signal generated by the digital intermediate frequency signal, then any order nonlinear expression of the PIM signal generated by the digital intermediate frequency signal is:

Among them, the operator |·| is the modulus value, and n is the time variable.

There are various expressions of the NL(|x(n)|) function, for example, multivariate polynomial, piecewise polyline, piecewise spline, etc. Exemplarily, taking the multivariate polynomial as an example, the nonlinear expression of the NL(|x(n)|) function is:

Among them, ch is the coefficient of each nonlinear component in the PIM signal, P is the maximum nonlinear order, 0≤p≤P.

Since the radio frequency system is a memory system, the memory characteristic is added to Equation 3, and the memory nonlinear expression of the NL(|x(n)|) function is obtained as:

Among them, M is the linear order of the memory system, which represents the maximum delay value of the baseband signal |x| after taking the modulus, which reflects the memory characteristics of the baseband signal |x| after taking the modulus, 0≤m≤M, 0 ≤p≤P.

Substituting Equation 4 into Equation 2, the expression of the PIM signal corresponding to the digital intermediate frequency signal Tx can be obtained as:

Among them, K is the linear order of the memory system, which represents the maximum delay value of the baseband signal x, reflecting the memory characteristics of the baseband signal x, 0≤k≤K, 0≤m≤M, 0≤p≤P.

Subtract the received signal rx containing the PIM signal from the PIM signal y of Equation 6 to obtain the cancellation result signal:

Among them, rx is the received signal containing the PIM signal, and rx _l is the received signal containing the PIM signal of the lth receiving channel. e _l is the cancellation result signal of the lth receiving channel, which represents the error between the received signal and the PIM cancellation signal in a statistical sense, and means that the received signal containing the PIM signal is canceled by the PIM signal in a physical sense. The received signal without PIM, 0≤k≤K, 0≤m≤M, 0≤p≤P.

The coefficient ch involved in formula 6 can usually be solved using the least mean squares (LMS) algorithm. The expression for solving the coefficient ch in formula 6 using the LMS algorithm is:

ch _l,k,m,p = ch _l,k,m,p +μ·e _l ·| x _m | ^p ·conj(x _k ) Equation 7

Among them, μ is the step factor of the iterative process when calculating the coefficient ch, and conj() is the conjugate operator.

In the above single-transmission and single-reception channel scenario, because the PIM signal is only generated in the RF transmission link, there is no leakage or radiation between the transmission channels. Therefore, the PIM signal is usually excited by a single independent transmission channel. There is no mutual influence and coupling. However, in the scenario of multiple transmit and multiple receive channels, the PIM signal may be generated at the antenna air interface or somewhere near the antenna or far-field space, that is, a multi-antenna radiated PIM signal is formed. This PIM signal is jointly excited by the digital intermediate frequency signals of multiple transmission channels in the form of a spatial electromagnetic field, and will affect the reception signals of multiple reception channels at the same time. The above-mentioned single-transmission single-reception channel PIM cancellation principle is no longer applicable. The reason is that the combination relationship of the multi-transmission channels is unknown, and the PIM signal in the scenario of multi-transmission and multi-reception channels cannot be obtained using Equation 2 or 3, so PIM cancellation cannot be achieved.

The following describes how to obtain the combined relationship of multiple transmit channels and how to obtain the corresponding multi-antenna radiated PIM signal in the scenario of multiple transmit and multiple receive channels.

Assuming that the function expression of the nonlinear component of the multi-antenna radiated PIM signal is NL(u_0,u_1...,u_Z), then:

Where u_z is the pre-combination signal of the baseband signal x of the z-th transmission channel, ch _{m, z} are the coefficients of the mathematical model of the combination relationship of the z-th transmission channel, and M is the number of coefficients in the z-th transmission channel , 0≤z≤Z, 0≤m≤M, n is a time variable.

For simplicity of description, take two transmit channels as an example:

Where u_0 is the pre-combination signal of the baseband signal x of the 0th transmission channel, and u_1 is the pre-combination signal of the baseband signal x of the first transmission channel.

Assuming that the combination of the two transmission channels is linear addition, the arbitrary order non-linear expression of the multi-antenna radiated PIM signal in the multi-transmit and multi-receive channels according to Equation 2 is:

y=(u_0+u_1)·NL(|u_0+u_1|) Formula 11

As can be seen from u_0+u_1, the PIM signal expression has changed from the original digital IF signal x of one transmission channel to a mixed signal u_0+u_1 of two transmission channel digital IF signals, that is, the digital IF of the two transmission channels The signals are linearly superimposed. In addition, as can be seen from NL(|u_0+u_1|), the digital intermediate frequency signals of the two transmission channels undergo a linear superposition to produce a nonlinear component.

Further, in order to compensate for the group delay characteristics introduced by the receiving channel and the receiving filter, a linear processing can be performed on the nonlinear signal of each transmitting channel once again based on Equation 11, the expression is:

Where y _z is an arbitrary-order nonlinear expression of the multi-antenna radiated PIM signal in the z-th transmission channel, ch _m,z is the m-th coefficient of the channel response mathematical model of the z-th transmission channel, and M is the The number of coefficients, 0≤m≤M.

The following describes how to design the PIM cancellation device and method provided in the embodiments of the present application according to the above theoretical model.

As shown in FIGS. 5-9, an embodiment of the present application provides a PIM cancellation device 500. The input of the PIM cancellation device 500 includes digital intermediate frequency signals (Tx_1~Tx_M) of M transmission channels and N reception channels. Received signals (Rx_1~Rx_N), where M is an integer greater than 1, and N is an integer greater than 1. As described above, the PIM cancellation device 500 obtains N PIM cancellation signals based on the digital intermediate frequency signals of M transmission channels, and differentiates N received signals and N PIM cancellation signals to obtain N cancellation result signals (err_1 ~err_N), as the output of the PIM cancellation device 500, is further used for processing such as frequency shift and rate reduction. Among them, FIGS. 5-9 respectively show several possible implementation manners of acquiring digital intermediate frequency signals (Tx_1˜Tx_M) of M transmission channels, which will be described in detail below.

As shown in FIG. 10, the PIM cancellation device 500 includes: a first acquisition unit 501, a second acquisition unit 502, a simulation unit 503, a cancellation unit 504, and an adjustment unit 505. The simulation unit 503 is connected to the first acquisition unit 501; the cancellation unit 504 is connected to the second acquisition unit 502 and the simulation unit 503; the adjustment unit 505 is connected to the cancellation unit 504 and the simulation unit 503.

The above units are used to execute the PIM cancellation method shown in FIG. 11. The above units will be described below in conjunction with the PIM cancellation method shown in FIG. 11.

As shown in FIG. 11, the PIM cancellation method includes S1101-S1105:

S1101: Acquire digital intermediate frequency signals of M transmission channels.

Specifically, the first acquiring unit 501 acquires digital intermediate frequency signals (Tx_1~Tx_M) of the M transmission channels. Where, M is an integer greater than 1.

In a possible implementation manner, as shown in FIG. 5, the first acquiring unit 501 can acquire the baseband signals of the M transmission channels; the baseband signals of the M transmission channels are ramped up and frequency-shifted to obtain M transmission channels Digital intermediate frequency signal.

In the transmit channel, the baseband signal is generated through memory (for example, double data rate (DDR) memory, random access memory (RAM), etc.) or baseband unit (building baseband unit, BBU), The baseband signal gets the digital intermediate frequency signal through the ascent rate and frequency shift, multi-carrier combining, enters the analog transmission channel through the DAC, and is transmitted to the space through the antenna after filtering by the transmission filter, forming a multi-antenna radiation PIM signal in the space, Therefore, the baseband signal is related to the PIM signal. It should be noted that when the digital intermediate frequency signal is obtained from the baseband signal, the baseband signal is converted into a digital intermediate frequency signal through the rate of rise and frequency shift.

In a possible implementation manner, as shown in FIG. 6, the first acquisition unit 501 may directly acquire digital intermediate frequency signals of M transmission channels.

In a possible implementation manner, as shown in FIG. 7, the first acquiring unit 501 may acquire the radio frequency signal between the transmit filter and the antenna in the M transmit channels, and the radio frequency signal may pass between the transmit filter and the antenna The analog coupling channel 701 is obtained; analog-to-digital conversion, frequency shift and rate reduction are performed on the radio frequency signal to obtain digital intermediate frequency signals of M transmission channels.

In a possible implementation manner, as shown in FIG. 8, the first acquiring unit 501 may acquire the radio frequency signal between the power amplifier and the transmit filter in the M transmit channels, and the radio frequency signal may pass between the power amplifier and the transmit filter The analog coupling channel 801 is obtained; analog-to-digital conversion, frequency shift and rate reduction are performed on the radio frequency signal to obtain digital intermediate frequency signals of M transmission channels.

In a possible implementation manner, as shown in FIG. 9, the first acquisition unit 501 may acquire the radio frequency signal radiated into the space through the antenna, and the radio frequency signal may be obtained by referring to the antenna 901; perform analog-to-digital conversion on the radio frequency signal, Shifting frequency and decreasing rate to obtain digital intermediate frequency signals of M transmitting channels.

After the multi-antenna radiating PIM signal is excited, all receiving antennas will receive it, so the multi-antenna radiating PIM signal can be received directly through the reference antenna. The number of reference antennas is the same as the actual number of antennas communicating.

S1102. Acquire received signals of N receiving channels.

Specifically, the second acquiring unit 502 acquires the received signals (Rx_1˜Rx_N) of the N receiving channels.

Among them, the received signal includes a PIM signal, which is generated by the digital intermediate frequency signals of the M transmission channels described above. The PIM signal may include at least one of a multi-antenna radiating PIM signal and a multi-antenna conductive PIM signal.

S1103. Obtain N PIM cancellation signals according to the digital intermediate frequency signals of M transmission channels.

Specifically, the analog unit 503 obtains N PIM cancellation signals (y_1~y_N) according to the digital intermediate frequency signals (Tx_1~Tx_M) of the M transmission channels.

Among them, the N PIM cancellation signals are used to cancel the PIM signals in the received signals (Rx_1~Rx_N) of the N receiving channels.

Specifically, as shown in FIGS. 12 and 13, the simulation unit 503 includes a first linear module L1 and a nonlinear module L2 connected in series.

The input of the first linear module L1 is the digital intermediate frequency signals (Tx_1～Tx_M) of the M transmission channels, and the first linear module L1 is used for the first filtering and the first filtering of the digital intermediate frequency signals (Tx_1～Tx_M) of the M transmission channels. Linear superposition, to obtain P first linear superposition results (u_1 ~ u_P), P is a positive integer.

Further, the first linear module L1 includes P first linear submodules L10. Each linear sub-module L10 of the P first linear sub-modules L10 is specifically used to perform first filtering on the digital intermediate frequency signals (Tx_1~Tx_M) of the M transmission channels respectively to obtain the results of the M first filtering, and The first linear superposition is performed on the M first filtered results to obtain one of the P first linear superposed results.

It should be noted that P can be determined according to system requirements (such as performance requirements, etc.), and this application is not limited. Exemplarily, P may be the number of PIM sources that excite the PIM signal, and each first linear submodule L10 corresponds to one PIM source.

Further, each first linear sub-module L10 includes a first linear adder L102 and M first filters L101, and each of the M first filters L101 is used for a transmission channel The digital intermediate frequency signal is subjected to first filtering to obtain one of the M first filtered results. The first linear adder L102 is used to perform the first linear superposition on the M first filtered results to obtain P first linear superimposed results. One of the results.

Combining with formula 11, because the digital intermediate frequency signals of M transmission channels are transmitted to the space through the antenna and then aggregated at the PIM fault point, this process can be regarded as a linear superposition process of the digital intermediate frequency signals of the M transmission channels in the space. Therefore, the first linear module L1 is used to simulate the linear superposition process of the digital intermediate frequency signals of the M transmission channels in space.

The first linear module L1 may be a linear adaptive finite impulse response (FIR) filter or infinite impulse response (IIR) filter with at least one tap, which may be used in the simulation space Memory characteristics during radiation and physical processes such as standing waves and reflections.

The nonlinear module L2 is used to perform nonlinear processing on the P first linear superimposed results (u_1~u_P), respectively, to obtain P nonlinear processing results. As shown in FIG. 12, the results of P nonlinear processing can be used as N PIM cancellation signals (y_1 ~ y_N), in which case P=N; or, as shown in FIG. 13, the results of P nonlinear processing (v_1 ~v_P) is used to generate the N PIM cancellation signals, in which case P≤N.

Further, the non-linear module L2 includes P non-linear sub-modules L20, and each non-linear sub-module is used to perform non-linear processing on one of the P first linear superposition results to obtain P non-linear processing results one of.

Because the digital intermediate frequency signals of the M transmission channels are transmitted to the space through the antenna and aggregated at the PIM fault point, a multi-antenna radiated PIM signal is formed, and the multi-antenna radiated PIM signal is received by the N receiving channels through different paths. As shown in Equation 2 or 3, the multi-antenna radiated PIM signal includes nonlinear components. Therefore, the nonlinear module L2 is used to simulate the process of linearly superimposing the digital intermediate frequency signals of the M transmission channels in space and exciting the PIM signal.

As shown in FIG. 13, the simulation unit 503 may further include a second linear module L3 connected in series after the nonlinear module L2.

The second linear module L3 is used to perform a second filtering on the results of the P nonlinear processing (v_1~v_P) output by the nonlinear module L2 to obtain N PIM cancellation signals (y_1~y_N).

Further, the second linear module L3 includes N second linear submodules L30, and each second linear submodule L30 of the N second linear submodules L30 is specifically used for one of the results of P nonlinear processing Perform the second filtering to obtain one of the P second filtering results.

Still further, each second linear sub-module L30 includes P second filters L301, and each second filter L301 of P second filters L301 is used for one of the results of P nonlinear processing Perform the second filtering to obtain one of the P second filtering results.

In addition, if P is greater than 1, the second linear submodule L30 further includes a second linear adder L302. The second linear adder L302 is used to perform a second linear addition on the results of the P second filtering to obtain N PIM pairs Cancel one of the signals.

If P is equal to 1, the second linear submodule L30 may not include the second linear adder L302, or include the second linear adder L302, but the second linear adder L302 does not perform the second linear superposition on the result of the second filtering , Direct transparent transmission will get one of the N PIM cancellation signals.

Combining with formula 12, the second linear module L3 can compensate the unevenness of the group delay introduced by the receiving channel and the receiving filter, which has the effect of improving the correction performance for broadband scenes.

The second linear module L3 may be a linear adaptive FIR filter or IIR filter with at least one tap.

It should be noted that in FIG. 12, P and N are equal, and M may be equal to or unequal to P/N. In FIG. 13, M, P, and N may be equal or unequal.

S1104. N cancellation result signals are obtained according to the received signal and the N PIM cancellation signals.

Specifically, the cancellation unit 1104 obtains N cancellation result signals according to the received signals of the N reception channels acquired by the second acquisition unit 1102 and the N PIM cancellation signals obtained by the simulation unit 1103.

In a possible implementation manner, the cancellation unit 1104 respectively differentiates the received signals of the N receiving channels and the N PIM cancellation signals to obtain N cancellation result signals. The N cancellation result signals respectively correspond to N receiving channels.

S1105: Adjust the filter coefficient of the first filter and the coefficient of nonlinear processing according to the N cancellation result signals, so that the filter coefficient of the first filter and the coefficient of nonlinear processing converge.

Specifically, the adjusting unit 1105 adjusts the filter coefficient of the first filter and the coefficient of nonlinear processing according to the N cancellation result signals obtained by the canceling unit 1104, so that the filter coefficient of the first filter and the coefficient of nonlinear processing converge.

When the analog unit 503 further includes a second linear module L3 connected in series after the nonlinear module L2, the adjustment unit 1105 may also adjust the filter coefficient of the second filter according to the N cancellation result signals obtained by the cancellation unit 1104, so that the second The filter coefficients of the filter converge.

The adjustment unit 1105 may use an adaptive filtering algorithm to calculate the coefficients of each module in the cancellation unit 1104, and store the coefficients in the coefficient memory for adjusting the coefficients of the corresponding modules. Adaptive filtering algorithms include least mean squares (LMS), recursive least squares (RLS) and other methods. Taking the LMS method as an example, through continuous iterative adjustment of the coefficients of each module, the mean square error of the received signal and the PIM cancellation signal continues to decrease until the mean square error cannot be reduced. The coefficients of each module enter the convergence state. The entire system reaches an adaptive optimal state.

The following describes how to calculate the coefficients of each module in the cancellation unit 1104.

The cost function of adaptive filtering (ie, the mean square error between the received signal and the PIM cancellation signal) is:

J(n)=e(n)·e ^* (n) Equation 13

Among them, e(n) is the cancellation result signal (that is, the error between the received signal and the PIM cancellation signal), and ^* represents conjugation.

Where y(n) is the received signal,

PIM cancellation signal.

Taking Figure 12 as an example, the

for:

Where x(n) is the digital intermediate frequency signal, Ch ₁ is the filter coefficient of the first filter in the first linear module L1, w is the coefficient of the nonlinear processing of the nonlinear module L2, NL is the nonlinear function, and p is the nonlinear The index of the base number of the function. i and j are time indexes used to represent the memory depth of the first linear module L1 and the nonlinear module L2.

The filter coefficient Ch of the first filter in the first linear module L1 can be expressed as:

Where μ is the iteration step size of the LMS algorithm,

Denotes derivation.

Using the cost function J(n) to separately derive the filter coefficients of the first filter in the first linear module L1 and the coefficients of the non-linear processing in the non-linear module L2, and substitute into Equation 16, the corresponding coefficient formula can be obtained.

For example, use the cost function J(n) to derivate the coefficients of the nonlinear processing in the nonlinear module L2:

Then the nonlinear processing coefficients in the nonlinear module L2 are:

Use the cost function J(n) to differentiate the filter coefficients of the first filter in the first linear module L1:

Then the filter coefficient of the first filter in the first linear module L1 is:

Taking Figure 13 as an example, the

for:

Where x(n) is the digital intermediate frequency signal, Ch ₁ is the filter coefficient of the first filter in the first linear module L1, w is the coefficient of the nonlinear processing in the nonlinear module L2, and Ch ₃ is the second filter in the second linear module L2 The filter coefficient of the second filter, NL is the nonlinear function, and p is the index of the base number of the nonlinear function. i, j, k are time indexes, used to represent the memory depth of the first linear module L1, the nonlinear module L2, and the second linear module L3.

The filter coefficient Ch of the first filter in the first linear module L1 or the filter coefficient Ch of the second filter in the second linear module L3 can be expressed as:

Where μ is the iteration step size of the LMS algorithm,

Denotes derivation.

Use the cost function J(n) to obtain the partial derivative of the filter coefficient of the first filter in the first linear module L1, the coefficient of the nonlinear processing in the nonlinear module L2, and the filter coefficient of the second filter in the second linear module L3, and Substituting into formula 22, the formula of the corresponding coefficient can be obtained.

For example, using the cost function J(n) to derivate the filter coefficient of the second filter in the second linear module L3:

Then the filter coefficient of the second filter in the second linear module L3 is:

Use the cost function J(n) to differentiate the coefficients of the nonlinear processing in the nonlinear module L2:

Then the nonlinear processing coefficients in the nonlinear module L2 are:

Use the cost function J(n) to differentiate the filter coefficients of the first filter in the first linear module L1:

Then the filter coefficient of the first filter in the first linear module L1 is:

The PIM cancellation device and method provided in the embodiments of the present application obtain digital intermediate frequency signals of M transmission channels, where M is an integer greater than 1. According to the digital intermediate frequency signals of the M transmission channels, N PIM cancellation signals are obtained, and N is an integer greater than 1. In the process of obtaining N PIM cancellation signals based on the digital intermediate frequency signals of the M digital intermediate frequency channels, the digital intermediate frequency signals of the M transmission channels are successively filtered, linearly superimposed, and nonlinearly processed. Obtain received signals containing PIM signals from N receiving channels. The N received signals and the N PIM cancellation signals are respectively differentiated to obtain N cancellation result signals. The cancellation result signal represents the error between the received signal and the PIM cancellation signal. By continuously adjusting the filter coefficients of the filter and the coefficients of nonlinear processing, the mean square of the error is gradually reduced. With the increase of time, the filtered filter coefficients and nonlinear processing coefficients tend to be stable, the mean square of the error tends to be minimum, the filtered filter coefficients and nonlinear processing coefficients converge, and the cancellation result signal at this time is no PIM received signals or received signals containing a small amount of PIM signals. Therefore, PIM cancellation is achieved in the scenario of multiple transmit and multiple receive channels.

An embodiment of the present application further provides a PIM cancellation device, including: a processor and a memory, where the memory is used to store a program, and the processor calls the program stored in the memory, so that the PIM cancellation device performs the correlation in FIG. 11 method.

Embodiments of the present application also provide a computer storage medium that stores one or more programs, on which a computer program is stored. When the computer program is executed by a processor, the PIM cancellation device executes the related method in FIG. 11.

An embodiment of the present application further provides a computer program product containing instructions, which, when the computer program product runs on the PIM cancellation device, causes the PIM cancellation device to execute the related method in FIG. 11.

An embodiment of the present application provides a chip system. The chip system includes a processor for a PIM cancellation device to execute the related method in FIG. 11. For example, obtain digital intermediate frequency signals of M transmitting channels, where M is an integer greater than 1; obtain received signals of N receiving channels, wherein the received signals include PIM signals, and the PIM signals are generated by digital intermediate frequency signals of M transmitting channels , N is an integer greater than 1; N PIM cancellation signals are obtained according to the digital intermediate frequency signals of the M transmission channels, where the N PIM cancellation signals are used to eliminate the PIM signal in the received signal, according to the numbers of the M transmission channels The N PIM cancellation signals obtained by the intermediate frequency signal include: performing the first filtering and the first linear superposition on the digital intermediate frequency signals of the M transmission channels to obtain the results of the P first linear superposition, and the results of the P first linear superposition respectively Perform nonlinear processing to obtain the results of P nonlinear processing. The results of P nonlinear processing are used to generate or serve as N PIM cancellation signals, P is a positive integer; according to the received signal and N PIM cancellation signals, N is obtained Cancellation result signals; adjust the filter coefficients of the first filter and the coefficients of nonlinear processing according to the N cancellation result signals, so that the filter coefficients of the first filter and the coefficients of nonlinear processing converge.

In a possible design, the chip system further includes a memory for storing necessary program instructions and data of the terminal device. The chip system may include a chip, an integrated circuit, or may include a chip and other discrete devices, which is not specifically limited in the embodiments of the present application.

Among them, the PIM cancellation device, computer storage medium, computer program product or chip system provided in this application are used to perform the PIM cancellation method described above, therefore, for the beneficial effects that can be achieved, please refer to the above The beneficial effects in the embodiment of the embodiment will not be repeated here.

Those of ordinary skill in the art may realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of computer software and electronic hardware. How these functions are implemented depends on the specific application of the technical solution and design constraints. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

Specific electronic hardware may include dedicated or general-purpose chips, field programmable gate arrays (field programmable gate arrays), discrete devices, application specific integrated circuits (application specific integrated circuits (ASIC), such as analog integrated circuits (IC), Digital integrated circuits, analog/digital hybrid integrated circuits, etc. This application does not limit the specific implementation form.

In the several embodiments provided in this application, it should be understood that the disclosed system, device, and method may be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the unit is only a logical function division, and in actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit.

In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a dedicated computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be from a website site, computer, server or data center Transmission to another website, computer, server or data center via wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device including one or more servers and data centers that can be integrated with the medium. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (SSD)) or the like.

The above is only the specific implementation of this application, but the scope of protection of this application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in this application. It should be covered by the scope of protection of this application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (23)

1. A passive intermodulation PIM cancellation device is characterized by comprising:

   The first acquiring unit is used to acquire digital intermediate frequency signals of M transmission channels, where M is an integer greater than 1;

   A second acquiring unit, configured to acquire received signals of N receiving channels, wherein the received signals include PIM signals, the PIM signals are generated from digital intermediate frequency signals of the M transmitting channels, and N is an integer greater than 1;

   An analog unit, connected to the first acquisition unit, is used to obtain N PIM cancellation signals according to the digital intermediate frequency signals of the M transmission channels, wherein the N PIM cancellation signals are used to cancel the reception The PIM signal in the signal, the analog unit includes a first linear module and a nonlinear module connected in series, the first linear module is used for performing first filtering and first linear superposition on the digital intermediate frequency signals of the M transmission channels To obtain P first linear superposition results, the nonlinear module is used to perform nonlinear processing on the P first linear superposition results, respectively, to obtain P nonlinear processing results, the P nonlinear The processed result is used to generate or serve as the N PIM cancellation signals, P is a positive integer;

   A cancellation unit, connected to the second acquisition unit and the simulation unit, for obtaining N cancellation result signals according to the received signal and the N PIM cancellation signals;

   An adjustment unit, connected to the cancellation unit and the simulation unit, is used to adjust the filter coefficient of the first filter and the coefficient of the nonlinear processing according to the N cancellation result signals, so that the first The filter coefficients of a filter and the coefficients of the nonlinear processing converge.
2. The apparatus according to claim 1, wherein the first acquiring unit is specifically configured to:

   Acquiring the baseband signals of the M transmission channels;

   The baseband signal is ramped up and frequency shifted to obtain the digital intermediate frequency signals of the M transmission channels.
3. The apparatus according to claim 1, wherein the first acquiring unit is specifically configured to:

   Acquiring radio frequency signals between the transmission filter and the antenna in the M transmission channels;

   Perform analog-to-digital conversion, frequency shift and rate reduction on the radio frequency signal to obtain the digital intermediate frequency signals of the M transmission channels.
4. The apparatus according to claim 1, wherein the first acquiring unit is specifically configured to:

   Acquiring radio frequency signals between the power amplifier and the transmission filter in the M transmission channels;

   Perform analog-to-digital conversion, frequency shift and rate reduction on the radio frequency signal to obtain the digital intermediate frequency signals of the M transmission channels.
5. The apparatus according to claim 1, wherein the first acquiring unit is specifically configured to:

   Obtain the radio frequency signal radiated into the space through the antenna;

   Perform analog-to-digital conversion, frequency shift and rate reduction on the radio frequency signal to obtain the digital intermediate frequency signals of the M transmission channels.
6. The device according to any one of claims 1-5, wherein the first linear module includes P first linear submodules; wherein,

   Each linear sub-module of the P first linear sub-modules is specifically used for performing first filtering on the digital intermediate frequency signals of the M transmission channels respectively to obtain M first filtering results, and The first linear superposition of the results of the M first filters results in a first linear superposition; where,

   Each of the first linear sub-modules includes a first linear adder and M first filters, and each of the M first filters is used to perform a first step on the digital intermediate frequency signal of a transmission channel One filtering results in a first filtering result, and the first linear adder is used to perform a first linear superposition on the M first filtering results to obtain the one first linear superposition result.
7. The apparatus according to any one of claims 1-6, wherein the nonlinear module includes P nonlinear sub-modules, and each of the nonlinear sub-modules is used to superimpose the P first linear One of the results is subjected to nonlinear processing to obtain a nonlinear processing result.
8. The device according to any one of claims 1-7, wherein the simulation unit further includes a second linear module connected in series after the nonlinear module,

   The second linear module is used to perform a second filtering on the results of the P nonlinear processes to obtain the N PIM cancellation signals; wherein,

   The second linear module includes N second linear sub-modules, and each second linear sub-module in the N second linear sub-modules is specifically configured to perform second filtering on the results of the P nonlinear processing , Get P second filtering results; where,

   Each of the second linear sub-modules includes P second filters, and each of the P second filters is used to perform a second process on one of the P nonlinear processing results Filtering to get a second filtering result;

   The adjusting unit is further configured to adjust the filter coefficient of the second filter according to the N cancellation result signals, so that the filter coefficient of the second filter converges.
9. The apparatus according to claim 8, wherein the P is greater than 1, and the second linear submodule further includes a second linear adder, and the second linear adder is used for the P second The filtered results are superimposed linearly to obtain a PIM cancellation signal.
10. The apparatus according to claim 8 or 9, wherein the second filter is a finite impulse response FIR filter or an infinite impulse response IIR filter.
11. The device according to claim 6, wherein the first filter is a FIR filter or an IIR filter.
12. A passive intermodulation PIM cancellation method, characterized in that it includes:

    Obtain digital intermediate frequency signals of M transmission channels, where M is an integer greater than 1;

    Acquiring received signals of N receiving channels, wherein the received signals include PIM signals, the PIM signals are generated from the digital intermediate frequency signals of the M transmitting channels, and N is an integer greater than 1;

    N PIM cancellation signals are obtained according to the digital intermediate frequency signals of the M transmission channels, wherein the N PIM cancellation signals are used to cancel the PIM signal in the received signal, and the M transmission channels are used according to Obtaining N PIM cancellation signals by the digital intermediate frequency signal of the digital signal includes: performing first filtering and first linear superposition on the digital intermediate frequency signals of the M transmission channels to obtain P first linear superposition results, and The results of a linear superposition are subjected to nonlinear processing to obtain P nonlinear processing results, and the P nonlinear processing results are used to generate or serve as the N PIM cancellation signals, and P is a positive integer;

    Obtaining N cancellation result signals according to the received signal and the N PIM cancellation signals;

    Adjusting the filter coefficients of the first filter and the coefficients of the nonlinear processing according to the N cancellation result signals, so that the filter coefficients of the first filter and the coefficients of the nonlinear processing converge.
13. The method according to claim 12, wherein the acquiring digital intermediate frequency signals of the M transmission channels comprises:

    Acquiring the baseband signals of the M transmission channels;

    The baseband signal is ramped up and frequency shifted to obtain the digital intermediate frequency signals of the M transmission channels.
14. The method according to claim 12, wherein the acquiring digital intermediate frequency signals of the M transmission channels comprises:

    Acquiring radio frequency signals between the transmission filter and the antenna in the M transmission channels;

    Perform analog-to-digital conversion, frequency shift and rate reduction on the radio frequency signal to obtain the digital intermediate frequency signals of the M transmission channels.
15. The method according to claim 12, wherein the acquiring digital intermediate frequency signals of the M transmission channels comprises:

    Acquiring radio frequency signals between the power amplifier and the transmission filter in the M transmission channels;

    Perform analog-to-digital conversion, frequency shift and rate reduction on the radio frequency signal to obtain the digital intermediate frequency signals of the M transmission channels.
16. The method according to claim 12, wherein the acquiring digital intermediate frequency signals of the M transmission channels comprises:

    Obtain the radio frequency signal radiated into the space through the antenna;

    Perform analog-to-digital conversion, frequency shift and rate reduction on the radio frequency signal to obtain the digital intermediate frequency signals of the M transmission channels.
17. The method according to any one of claims 12 to 16, wherein the first filtering and the first linear superposition are performed on the digital intermediate frequency signals of the M transmission channels to obtain P first linear superposition results ,include:

    Performing first filtering on the digital intermediate frequency signals of the M transmission channels respectively to obtain M first filtering results; performing first linear superposition on the M first filtering results to obtain the P first linear One of the superimposed results.
18. The method according to any one of claims 12-17, wherein the performing nonlinear processing on the P first linear superposition results respectively to obtain P nonlinear processing results includes:

    Performing nonlinear processing on one of the P first linearly superimposed results to obtain one of the P nonlinear processing results.
19. The method according to any one of claims 12-18, wherein the method further comprises:

    Performing a second filtering on the results of the P nonlinear processes to obtain the N PIM cancellation signals; wherein, performing a second filtering on the results of the P nonlinear processes to obtain the N PIMs Canceling the signal, including: performing a second filtering on one of the P nonlinear processing results to obtain one of the P second filtering results;

    Adjusting the filter coefficient of the second filter according to the N cancellation result signals, so that the filter coefficient of the second filter converges.
20. The method according to claim 19, wherein the P is greater than 1, and the method further comprises:

    Performing a second linear superposition on the P second filtered results to obtain one of the N PIM cancellation signals.
21. A computer-readable storage medium storing one or more programs, characterized in that the one or more programs include instructions, which when executed by a computer causes the computer to execute any one of claims 12-20 Item PIM cancellation method.
22. A computer program product containing instructions, characterized in that, when the instructions run on a computer, the computer is caused to execute the PIM cancellation method according to any one of claims 12-20.
23. A PIM cancellation device, comprising: a processor and a memory, the memory is used to store a program, and the processor calls the stored program in the memory to perform the PIM cancellation method according to any one of claims 12-20 .

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