A passive intermodulation correction method and system based on FDD system

Abstract

The present invention proposes a passive intermodulation correction method and system based on an FDD system, relating to the field of passive intermodulation correction. The method comprises: selecting transmit signals on two carriers and feeding them together into a PIM distortion signal module to obtain a PIM interference signal on the receiving band; synthesizing the PIM interference signal with the received signal to obtain an interference received signal; performing delay compensation processing on the interference received signal to obtain a delay-compensated received signal; feeding the delay-compensated received signal and the transmit signal into a PIM estimation module to obtain an estimated PIM interference signal; and obtaining an estimated received signal based on the interference received signal and the estimated PIM interference signal. The system includes an interference acquisition module, an interference synthesis module, an interference delay module, an interference estimation module, and an interference correction module. By proposing a simple passive intermodulation correction method, PIM signals can be quickly and conveniently corrected, thereby improving the receiving performance of the communication system.

Description

Technical Field

[0001] The present invention relates to the field of passive intermodulation correction, and in particular to a passive intermodulation correction method and system based on an FDD system. Background Art

[0002] As the amount of user data in mobile communication systems increases, the requirements for system throughput and data capacity are also increasing. Numerous solutions are being proposed to meet these demands. The most widely used technology today is carrier aggregation (CA), introduced in LTE-A, which transmits data across multiple carriers. However, passive components in RF transceivers, such as duplexers and multiplexers, can introduce passive intermodulation (PIM). In some scenarios, PIM signals can fall within the receive band, affecting reception performance.

[0003] In communications systems, passive intermodulation (PIM) refers to the phenomenon whereby two or more transmitted carriers, passing through the same passive RF transmission system, generate nonlinear frequency components between the baseband signals, leading to interference. Especially with the prevalence of high-power, multi-channel communication systems, PIM interference caused by the nonlinearity of various passive components within the RF system is increasingly impacting receiver performance. Therefore, a simple and quick method is urgently needed to correct PIM signals at the receiver to improve reception performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a passive intermodulation correction method and system based on an FDD system. By proposing a simple passive intermodulation correction processing method, it is possible to conveniently and quickly correct the PIM signal and improve the receiving performance of the communication system.

[0005] The embodiment of the present invention is achieved as follows:

[0006] In a first aspect, an embodiment of the present application provides a passive intermodulation correction method based on an FDD system, comprising the following steps:

[0007] Select the transmit signals on the two carriers and send them together to the PIM distortion signal module to obtain the PIM interference signal on the receiving band;

[0008] The PIM interference signal and the receiving signal are synthesized to obtain an interference receiving signal;

[0009] Performing delay compensation processing on the interference receiving signal to obtain a delay compensated receiving signal;

[0010] The delay-compensated received signal and the transmitted signal are fed into the PIM estimation module to obtain an estimated PIM interference signal;

[0011] An estimated received signal is obtained based on the interfering received signal and the estimated PIM interference signal.

[0012] In some embodiments of the present invention, the step of combining the PIM interference signal and the received signal to obtain the interference received signal specifically includes: adding the PIM interference signal to the received signal to obtain the interference received signal.

[0013] In some embodiments of the present invention, the above expression for estimating the PIM interference signal is: PIM =αΦ, where y PIM To estimate the PIM interference signal, α is the PIM interference coefficient, Φ is the basic matrix of the transmitted signal, and it is obtained based on the transmitted signals on two randomly selected carriers.

[0014] In some embodiments of the present invention, the PIM interference coefficient α is estimated based on minimum mean square error.

[0015] In some embodiments of the present invention, the estimated result expression of the above-mentioned PIM interference coefficient α is: in, is the estimated value of the PIM interference coefficient α, R is the relevant calculation rule, and the expression is: R xx =E{x·x *}, R yΦ is the cross-correlation function, R ΦΦ is the autocorrelation function.

[0016] In some embodiments of the present invention, the calculation process of the PIM interference coefficient α specifically includes:

[0017] Repeatedly calculate the cross-correlation function R based on the transmitted signal and the received signal yΦ and autocorrelation function R ΦΦ , get multiple groups of corresponding correlation matrices;

[0018] Based on the correlation matrix, the average processing is performed to obtain the cross-correlation function R yΦ and autocorrelation function R ΦΦ The average value of the cross-correlation function R yΦ Mean and autocorrelation function R ΦΦ average value;

[0019] Based on the autocorrelation function R ΦΦ The autocorrelation function R is obtained by calculating the average value ΦΦ The inverse matrix of the corresponding matrix

[0020] Based on the inverse matrix and the cross-correlation function R yΦ The average value is used to obtain the estimated value of the PIM interference coefficient α.

[0021] In a second aspect, an embodiment of the present application provides a passive intermodulation correction system based on an FDD system, comprising:

[0022] The interference acquisition module is used to select the transmission signals on the two carriers and send them together to the PIM distortion signal module to obtain the PIM interference signal on the receiving band;

[0023] An interference synthesis module is used to synthesize the PIM interference signal and the receiving signal to obtain an interference receiving signal;

[0024] The interference delay module is used to perform delay compensation processing on the interference receiving signal to obtain a delay compensated receiving signal;

[0025] An interference estimation module is used to send the delay-compensated received signal and the transmitted signal to the PIM estimation module to obtain an estimated PIM interference signal;

[0026] The interference correction module is configured to obtain an estimated received signal based on the interference received signal and the estimated PIM interference signal.

[0027] In a third aspect, an embodiment of the present application provides an electronic device comprising a memory for storing one or more programs and a processor. When the one or more programs are executed by the processor, the method described in any one of the first aspects is implemented.

[0028] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described in any one of the above-mentioned first aspects.

[0029] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0030] The present invention proposes a passive intermodulation correction method based on an FDD system. First, the transmitted signals on two carriers are selected and fed together into a PIM distortion signal module to obtain a PIM interference signal on the receiving band. This PIM interference signal is then added to the received signal to produce an interfered received signal. The interfered received signal is then delay-compensated to obtain a delay-compensated received signal synchronized with the received signal. The delay-compensated received signal and the transmitted signal are then fed into a PIM estimation module to obtain an estimated PIM interference signal, or in other words, an estimated PIM interference signal. Finally, the estimated PIM interference signal is removed from the interfered received signal to obtain a final estimated received signal, completing the passive intermodulation correction process for the received signal. The method is simple and clear, easy to implement, and consumes minimal system memory resources. It can quickly and easily correct PIM signals, improving the receiving performance of the communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 This is a flow chart of an embodiment of a passive intermodulation correction method based on an FDD system according to the present invention;

[0033] Figure 2 This is a flow chart of another embodiment of a passive intermodulation correction method based on an FDD system according to the present invention;

[0034] Figure 3 Detailed flowchart of the steps for calculating the PIM interference coefficient α in an embodiment of the present invention;

[0035] Figure 4 This is a structural block diagram of an embodiment of a passive intermodulation correction system based on an FDD system according to the present invention;

[0036] Figure 5 This is a structural block diagram of an electronic device provided by an embodiment of the present invention.

[0037] Icon: 1. Interference acquisition module; 2. Interference synthesis module; 3. Interference delay module; 4. Interference estimation module; 5. Interference correction module; 6. Memory; 7. Processor; 8. Communication interface. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0040] It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. At the same time, in the description of this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0041] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features thereof may be combined with each other.

[0042] Example

[0043] See also Figure 1 and Figure 2 , the passive intermodulation correction method based on the FDD system includes the following steps:

[0044] Step S101: selecting transmission signals on two carriers and sending them together to a PIM distortion signal module to obtain a PIM interference signal on a receiving band.

[0045] Most people have experienced the inconvenience of noise, audio distortion, or even sudden disconnections during a mobile phone call. While these issues are often attributed to poor signal quality in certain locations by the phone manufacturer or network service provider, they are sometimes caused by signal distortion generated by base station towers. One cause of this distortion is passive intermodulation (PIM). Fundamentally, PIM is a process in nonlinear devices or propagation media where the spectral components of two or more input signals interact to produce new interfering components whose frequencies are linear combinations of integer multiples of the input signal frequencies. If these new signals enter the receive band, they interfere with and distort the original signals transmitted between the two wireless systems. Any passive device will generate PIM products when more than one frequency is present in the device. Therefore, to ensure reliable communication performance, PIM distortion must be limited or eliminated. In the above steps, due to the loop delay between the received and transmitted signals, the received and transmitted signals must be processed synchronously. That is to say, by selecting the transmission signals on the two carriers and sending them together to the PIM distortion signal module, the PIM interference signal on the receiving band is obtained, which can provide original data support for the subsequent passive intermodulation correction processing.

[0046] For example, the selection of the transmission signals on the two carriers may be random or based on the frequency of use. The present invention does not limit the selection method, as long as the selection of the transmission signals on the two carriers can be achieved.

[0047] Step S102: synthesize the PIM interference signal and the received signal to obtain an interference received signal.

[0048] In the above steps, the PIM interference signal is first synthesized with the received signal to obtain the interference received signal, that is, the transmitted signal is first synthesized and added to the received signal, and then the estimated PIM interference signal is removed, which can achieve passive intermodulation correction of the received signal.

[0049] Specifically, the step of combining the PIM interference signal with the received signal to obtain the interfering received signal includes: adding the PIM interference signal to the received signal to obtain the interfering received signal. That is, when combining the PIM interference signal with the received signal, a simple direct addition process can be employed to obtain the received signal to which the PIM interference signal is added. Subsequently, the corresponding estimated PIM interference signal can be simply subtracted to achieve passive intermodulation correction of the received signal. Of course, other synthesis methods can also be employed during the synthesis process, such as multiplying the PIM interference signal by an adjustment coefficient before adding it to the received signal. In this manner, a corresponding proportional adjustment can be performed when the estimated PIM interference signal is subsequently removed.

[0050] Step S103: performing delay compensation processing on the interference received signal to obtain a delay compensated received signal.

[0051] In the above steps, since there is a loop delay between the received signal and the transmitted signal, the interference received signal is subjected to delay compensation processing, which enables the obtained delay-compensated received signal to be synchronized with the received signal, thereby facilitating subsequent correction processing.

[0052] Step S104: sending the delay-compensated received signal and the transmitted signal to a PIM estimation module to obtain an estimated PIM interference signal.

[0053] In the above steps, the synchronized delay-compensated received signal and transmitted signal are fed into the PIM estimation module to obtain an estimated PIM interference signal. That is, the estimated PIM interference signal of the system is obtained. Subsequently, passive intermodulation correction processing of the received signal can be achieved by removing the estimated PIM interference signal.

[0054] Specifically, the expression for estimating the PIM interference signal is: PIM =αΦ, where y PIM To estimate the PIM interference signal, α is the PIM interference coefficient, Φ is the basic matrix of the transmitted signal, and it is obtained based on the transmitted signals on two randomly selected carriers.

[0055] In the above steps, the transmit signal basis matrix Φ can be obtained from the transmit signals on the two selected carriers. Different signal models will have different basis function compositions, but this does not affect subsequent processing. After constructing the above expression for estimating the PIM interference signal, α is the PIM interference coefficient, the parameter to be estimated. Subsequent parameter estimation of parameter α will yield an accurate estimate of the PIM interference signal.

[0056] In the prior art, the least squares (LS) estimation algorithm is usually used in signal estimation. The α parameter estimation based on LS can be expressed as: The specific principle is to construct a matrix Φ using two transmitted signals of length N, with y being the original received signal of the corresponding length. Multiple calculations are performed on the signal, each time for data of length N, to obtain a set of estimated values ​​for α. These sets of estimated values ​​are then averaged to obtain the final estimate, thereby performing intermodulation distortion correction. This scheme has high computational complexity, as each calculation on a signal of length N requires a matrix inversion. For some complex signal models, the matrix required for parameter estimation is of high order and requires multiple calculations, significantly increasing the difficulty of algorithm implementation.

[0057] Correspondingly, in embodiments of the present invention, the PIM interference coefficient α can be estimated using minimum mean square error (MMSE). The key concept is to utilize signal correlation for parameter estimation. The interference signal in the received signal is correlated with the transmitted signal, while the non-interference signal portion of the received signal is uncorrelated with the transmitted signal.

[0058] Specifically, when performing parameter estimation based on the minimum mean square error, the estimated result expression of the PIM interference coefficient α can be: in, is the estimated value of the PIM interference coefficient α, R is the relevant calculation rule, and the expression is: R xx =E{x·x *}, R yΦ is the cross-correlation function, R ΦΦ is the autocorrelation function.

[0059] In the above steps, by constructing the cross-correlation function between the estimated PIM interference signal and the transmit signal base matrix, as well as the autocorrelation function of the transmit signal base matrix, and then constructing the estimated expression for the PIM interference coefficient α based on the two, the correlation of the signals can be used for parameter estimation.

[0060] Specifically, see Figure 3 The calculation process of the above-mentioned PIM interference coefficient α specifically includes:

[0061] Step S201: Repeatedly calculate the cross-correlation function R based on the transmitted signal and the received signal. yΦ and autocorrelation function R ΦΦ , and obtain multiple groups of corresponding correlation matrices.

[0062] In the above steps, the cross-correlation function R is calculated by using the transmitted and received signals of length N. yΦ and autocorrelation function R ΦΦ After repeated calculations, multiple sets of corresponding correlation matrices can be obtained, which will provide original data support for subsequent corresponding processing.

[0063] Step S202: averaging the correlation matrix to obtain the cross-correlation function R yΦ and autocorrelation function R ΦΦ The average value of the cross-correlation function R yΦ Mean and autocorrelation function R ΦΦ average value.

[0064] In the above steps, by the cross-correlation function R yΦ and autocorrelation function R ΦΦThe averaging process can eliminate the influence of white noise on subsequent estimation results to a certain extent, making the subsequent calculation results more accurate and reliable.

[0065] Step S203: Based on the autocorrelation function R ΦΦ The autocorrelation function R is obtained by calculating the average value ΦΦ The inverse matrix of the corresponding matrix

[0066] Step S204: Based on the inverse matrix and the cross-correlation function R yΦ The average value is used to obtain the estimated value of the PIM interference coefficient α.

[0067] In the above steps, the autocorrelation function R ΦΦ The corresponding matrix is ​​inverted to obtain the inverse matrix Then and the cross-correlation function R yΦ Multiplying the average values ​​will yield an accurate and effective estimate of the PIM interference coefficient α.

[0068] In summary, compared with the conventional method of using the least squares (LS) estimation algorithm for estimation, the solution in steps S201-S204 only requires the autocorrelation function R ΦΦ The corresponding matrix is ​​inverted once, which can greatly reduce the computational complexity and resource consumption compared with the least squares estimation algorithm. At the same time, by yΦ and autocorrelation function R ΦΦ Performing averaging can, to a certain extent, eliminate the impact of white noise on subsequent estimation results, making subsequent calculation results more accurate and reliable. In other words, estimating the PIM interference coefficient α using the solution in steps S201-S204 simplifies the calculation process, making it easier to implement, while also reducing system memory consumption and improving noise immunity.

[0069] Step S105: obtaining an estimated received signal based on the interfering received signal and the estimated PIM interference signal.

[0070] In the above steps, the estimated received signal is obtained by removing the estimated PIM interference signal (the estimated possible PIM interference signal) from the received signal to which the PIM interference signal has been added (i.e., the interfering received signal), thereby obtaining the estimated received signal after passive intermodulation correction (i.e., the corrected received signal). Of course, if the PIM interference signal and the received signal are combined to obtain the interfering received signal by addition, then the estimated received signal is obtained based on the interfering received signal and the estimated PIM interference signal by subtracting the estimated PIM interference signal from the interfering received signal, thereby obtaining the corresponding estimated received signal. Accordingly, if another synthesis method is used during synthesis, the corresponding estimated received signal can be obtained by performing the inverse of the synthesis process based on the interfering received signal and the estimated PIM interference signal.

[0071] Based on the same inventive concept, please refer to Figure 4 The present invention also proposes a passive intermodulation correction system based on an FDD system, comprising:

[0072] Interference acquisition module 1 is used to select the transmission signals on two carriers and send them together to the PIM distortion signal module to obtain the PIM interference signal on the receiving band;

[0073] Interference synthesis module 2, used to synthesize the PIM interference signal and the received signal to obtain an interference received signal;

[0074] Interference delay module 3, used for performing delay compensation processing on the interference received signal to obtain a delay compensated received signal;

[0075] Interference estimation module 4, used to send the delay-compensated received signal and the transmitted signal to the PIM estimation module to obtain an estimated PIM interference signal;

[0076] The interference correction module 5 is configured to obtain an estimated received signal based on the interference received signal and the estimated PIM interference signal.

[0077] For the specific implementation process of the above system, please refer to the passive intermodulation correction method based on the FDD system provided in the embodiment of the present application, which will not be repeated here.

[0078] See also Figure 5 , Figure 5This is a block diagram of the structure of an electronic device provided in an embodiment of the present invention. The electronic device includes a memory 6, a processor 7, and a communication interface 8. The memory 6, processor 7, and communication interface 8 are electrically connected to each other directly or indirectly to enable data transmission or interaction. For example, these components can be electrically connected to each other via one or more communication buses or signal lines. The memory 6 can be used to store software programs and modules, such as program instructions / modules corresponding to a passive intermodulation correction system based on an FDD system provided in an embodiment of the present application. The processor 7 executes various functional applications and data processing by executing the software programs and modules stored in the memory 6. The communication interface 8 can be used to communicate signaling or data with other node devices.

[0079] Among them, the memory 6 can be, but is not limited to, a random access memory (RAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc.

[0080] The processor 7 can be an integrated circuit chip with signal processing capabilities. The processor 7 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0081] I understand. Figure 5 The structure shown is only for illustration, and the electronic device may also include Figure 5 More or fewer components than shown, or with Figure 5 Different configurations shown. Figure 5 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0082] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions.

[0083] In addition, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0084] If the above functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) 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 disk.

[0085] The foregoing description is merely a preferred embodiment of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

[0086] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present application is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A passive intermodulation correction method based on an FDD system, characterized in that: The following steps are involved: Select the transmit signals on the two carriers and send them together to the PIM distortion signal module to obtain the PIM interference signal on the receiving band; The PIM interference signal and the receiving signal are synthesized to obtain an interference receiving signal; Performing delay compensation processing on the interference receiving signal to obtain a delay compensated receiving signal; The delay-compensated received signal and the transmitted signal are fed into a PIM estimation module to obtain an estimated PIM interference signal; Obtaining an estimated received signal based on the interfering received signal and the estimated PIM interference signal; The expression for estimating the PIM interference signal is: PIM =αΦ, where y PIM To estimate the PIM interference signal, α is the PIM interference coefficient, Φ is the transmit signal basis matrix, and it is obtained based on the transmit signals on two randomly selected carriers; The estimated result expression of the PIM interference coefficient α is: in, is the estimated value of the PIM interference coefficient α, R is the relevant calculation rule, and the expression is: R xx =E{x·x * }, R yΦ is the average value of the cross-correlation function, R ΦΦ is the average value of the autocorrelation function, and y is the received signal.

2. The passive intermodulation correction method based on the FDD system according to claim 1, characterized in that: The step of synthesizing the PIM interference signal and the received signal to obtain the interference received signal specifically includes: adding the PIM interference signal to the received signal to obtain the interference received signal.

3. The passive intermodulation correction method based on the FDD system according to claim 1, characterized in that: The PIM interference coefficient α is estimated based on the minimum mean square error.

4. The passive intermodulation correction method based on the FDD system according to claim 1, wherein: The calculation process of the PIM interference coefficient α specifically includes: Repeatedly calculate the cross-correlation function R' based on the transmitted signal and the received signal yΦ and autocorrelation function R' ΦΦ , get multiple groups of corresponding correlation matrices; Based on the correlation matrix, the average processing is performed to obtain the cross-correlation function R' yΦ and autocorrelation function R' ΦΦ The average value of the cross-correlation function is respectively recorded as the average value R yΦ and the mean value of the autocorrelation function R ΦΦ ; Based on the average value of the autocorrelation function R ΦΦ Calculate the average value of the autocorrelation function R ΦΦ The inverse matrix of the corresponding matrix Based on the inverse matrix and the mean value of the cross-correlation function R yΦ An estimated value of the PIM interference coefficient α is obtained.

5. A passive intermodulation correction system based on an FDD system, characterized in that: include: The interference acquisition module is used to select the transmission signals on the two carriers and send them together to the PIM distortion signal module to obtain the PIM interference signal on the receiving band; An interference synthesis module is used to synthesize the PIM interference signal and the receiving signal to obtain an interference receiving signal; The interference delay module is used to perform delay compensation processing on the interference receiving signal to obtain a delay compensated receiving signal; The interference estimation module is used to send the delay-compensated received signal and the transmitted signal to the PIM estimation module to obtain an estimated PIM interference signal; An interference correction module is configured to obtain an estimated received signal based on the interference received signal and the estimated PIM interference signal; The expression for estimating the PIM interference signal is: PIM =αΦ, where y PIM To estimate the PIM interference signal, α is the PIM interference coefficient, Φ is the transmit signal basis matrix, and it is obtained based on the transmit signals on two randomly selected carriers; The estimated result expression of the PIM interference coefficient α is: in, is the estimated value of the PIM interference coefficient α, R is the relevant calculation rule, and the expression is: R xx =E{x·x * }, R yΦ is the average value of the cross-correlation function, R ΦΦ is the average value of the autocorrelation function, and y is the received signal.

6. An electronic device, characterized in that: include: a memory for storing one or more programs; processor; When the one or more programs are executed by the processor, the method according to any one of claims 1 to 4 is implemented.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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