Frequency-offset band-limited digital predistortion method, system, electronic device, chip system, storage medium and program product

Abstract

Embodiments of the present application provide a frequency-offset, band-limited digital predistortion method, system, electronic device, chip system, storage medium, and program product, relating to the field of terminal technology and facilitating improved sideband correction capabilities of a digital predistortion system. The method comprises: a frequency-offset, band-limited digital predistorter acquiring a first baseband signal, determining a first frequency offset value, using a first set of basis functions constructed based on the first frequency offset value from at least one set of basis functions as a function for processing the first baseband signal, using a first set of distortion coefficients corresponding to the first set of basis functions as the distortion coefficients for processing the first baseband signal, and then outputting a first processing result for the first baseband signal.

Description

Technical Field

[0001] The present application relates to the field of terminal technology, and in particular to a frequency-offset band-limited digital predistortion method, system, electronic device, chip system, storage medium, and program product. Background Art

[0002] The original signals generated by electronic devices (such as voice, application data, etc.) are usually baseband signals with low frequencies. Electronic devices need to modulate the original signals to a specified frequency band to meet the frequency band requirements of various communication operators. Furthermore, in order to achieve long-distance transmission, electronic devices usually need to amplify the power through a power amplifier to ensure that the modulated high-frequency signal has sufficient energy to achieve long-distance transmission, and filter out excess frequency bands before the signal is transmitted to reduce the interference of the signal on other signals.

[0003] However, the nonlinear characteristics of the power amplifier may cause distortion in the signal processed by the power amplifier. Based on this, in the related art, a digital pre-distortion system is set before the power amplifier to correct the signal distortion problem caused by the power amplifier. However, due to the setting of the filter and the frequency offset of the transmitted signal, the correction capability of the digital pre-distortion system still needs to be improved. Summary of the Invention

[0004] The embodiments of the present application provide a frequency-offset band-limited digital predistortion method, system, electronic device, chip system, storage medium, and program product, which are conducive to improving the processing accuracy and reliability of the frequency-offset band-limited digital predistorter.

[0005] In a first aspect, an embodiment of the present application proposes a frequency-offset band-limited digital predistortion method, which is applied to a frequency-offset band-limited digital predistortion system, wherein the frequency-offset band-limited digital predistortion system includes a frequency-offset band-limited digital predistorter and a first filter, wherein the frequency-offset band-limited digital predistorter includes at least one group of basis functions and a group of distortion coefficients corresponding to each group of basis functions in the at least one group of basis functions. The method includes: the frequency-offset band-limited digital predistorter obtains a first baseband signal and determines a first frequency offset value, wherein the first frequency offset value is the difference between the center frequency of the radio frequency signal corresponding to the first baseband signal and the center frequency of the first filter; the frequency-offset band-limited digital predistorter converts the at least one group of basis functions, A first group of basis functions constructed based on the first frequency offset value is used as a function for processing the first baseband signal, and a first group of distortion coefficients corresponding to the first group of basis functions is used as the distortion coefficients for processing the first baseband signal; the first group of distortion coefficients is obtained by training the first group of basis functions based on the distortion signal collected by the frequency-offset-band-limited digital predistortion system and the baseband signal corresponding to the distortion signal; the frequency-offset-band-limited digital predistorter outputs a first processing result of the first baseband signal; the first processing result includes: the cumulative result of multiplying the second processing result of each basis function in the first group of basis functions on the first baseband signal by the distortion coefficient corresponding to each basis function.

[0006] In the method provided in an embodiment of the present application, a frequency-offset, band-limited digital predistorter considers the center frequency offset of the RF signal corresponding to the first baseband signal during processing of the first baseband signal. This offset may cause the subsequent first filter to filter the RF signal in different ranges each time, further affecting the entire system's ability to correct the distorted signal. Therefore, in an embodiment of the present application, the frequency-offset, band-limited digital predistorter can determine and select corresponding basis functions and distortion coefficients based on the first frequency offset value to ensure that the center frequency offset of the first baseband signal processed by the frequency-offset, band-limited digital predistorter is consistent with the offset of the corresponding RF signal. This helps ensure that the subsequent first filter maintains a consistent filtering range for each input RF signal. This also means that the frequency-offset, band-limited digital predistorter system can obtain distorted signals with consistent filtering ranges in training scenarios. The distortion coefficients obtained through training on this basis are more reliable, which helps improve the processing accuracy and reliability of the frequency-offset, band-limited digital predistorter and the sideband correction capability of the digital predistortion system.

[0007] In combination with the first aspect, in certain implementations of the first aspect, the frequency-offset band-limited digital predistorter includes a second filter, and the bandwidth of the second filter is the same as that of the first filter; the processing of the first baseband signal by the frequency-offset band-limited digital predistorter based on each basis function in the first group of basis functions includes: performing a first frequency conversion processing on the first baseband signal to obtain a second baseband signal, and the absolute difference between the center frequency of the second baseband signal and the center frequency of the first baseband signal is the first frequency offset value; passing the second baseband signal through the second filter to obtain a third baseband signal; performing a second frequency conversion processing on the third baseband signal to obtain a fourth baseband signal, and the second processing result includes the fourth baseband signal, the second frequency conversion processing and the first frequency conversion processing have frequency offsets in opposite directions, and the absolute difference between the center frequency of the fourth baseband signal and the center frequency of the third baseband signal is the first frequency offset value.

[0008] In an embodiment of the present application, the first frequency conversion processing causes the frequency-shifted band-limited digital predistorter to perform a frequency shift on the first baseband signal to obtain a second baseband signal. The frequency shift is the same as the frequency shift of the center frequency of the corresponding RF signal and the center frequency of the first filter. On this basis, the second baseband signal is filtered using a second filter with the same bandwidth as the first filter. The resulting third baseband signal has the same signal segment as the RF signal subsequently processed by the first filter. The fourth baseband signal obtained by the second frequency conversion processing is then at the same zero-frequency position as the first baseband signal to ensure that the first baseband signal maintains its original frequency after processing. This is beneficial for correcting the influence of the frequency offset of the RF signal on the frequency-shifted band-limited digital predistorter and for improving the frequency-shifted band-limited digital predistorter's ability to correct the nonlinearity of the power amplifier.

[0009] Furthermore, the frequency-offset band-limited digital pre-distorter includes a second filter, which has the same bandwidth as the first filter. That is, the frequency-offset band-limited digital pre-distorter is trained for the bandwidth intercepted by the first filter and does not involve the filtered bandwidth part, which is conducive to saving the computing power of the frequency-offset band-limited digital pre-distorter and ensuring its accuracy.

[0010] Optionally, the second filter is a low-pass filter.

[0011] In combination with the first aspect, in certain implementations of the first aspect, the frequency-offset band-limited digital predistorter includes a third filter, and the bandwidth of the third filter is the same as that of the first filter; the processing of the first baseband signal by the frequency-offset band-limited digital predistorter based on each basis function in the first group of basis functions includes: passing the first baseband signal through the third filter to obtain a fifth baseband signal, the second processing result includes the fifth baseband signal, and the center frequency of the third filter is a second frequency offset value, and the second frequency offset value is the inverse of the first frequency offset value.

[0012] In an embodiment of the present application, the frequency-deviation band-limited digital predistorter includes a third filter, whose center frequency is the second frequency offset value. In this way, the fifth baseband signal obtained by passing the first baseband signal through the third filter has the same signal segment as the radio frequency signal subsequently processed by the first filter, which is beneficial to correcting the influence of the frequency deviation of the radio frequency signal on the frequency-deviation band-limited digital predistorter, and is beneficial to improving the frequency-deviation band-limited digital predistorter's ability to correct the nonlinearity of the power amplifier.

[0013] Optionally, the third filter is a bandpass filter.

[0014] In combination with the first aspect, in certain implementations of the first aspect, each of the at least one group of basis functions is one or more of a memory polynomial, a generalized memory polynomial, or a dynamic deviation reduction model.

[0015] In a second aspect, the present application provides a frequency-offset-band-limited digital predistortion system, comprising a first path formed by a frequency-offset-band-limited digital predistorter, a digital-to-analog converter, a modulator, a power amplifier, a first filter, and a coupler, and a second path formed by a digital-to-analog converter, a modulator, a power amplifier, a first filter, a coupler, a demodulator, an analog-to-digital converter, and a frequency-offset-band-limited digital predistortion training module; when the frequency-offset-band-limited digital predistortion system is in an application scenario, the frequency-offset-band-limited digital predistorter in the first path is used to implement the method described in the first aspect or any possible implementation manner of the first aspect; when the frequency-offset-band-limited digital predistortion system is in a training scenario, the second path is used to feed back a distortion signal, and obtain distortion coefficients for the frequency-offset-band-limited digital predistorter based on training of the distortion signal.

[0016] In a third aspect, the present application provides an electronic device, comprising a frequency-offset band-limited digital predistortion system.

[0017] In a fourth aspect, an embodiment of the present application provides an electronic device comprising one or more processors and a memory, wherein the memory is coupled to the one or more processors, the memory being used to store computer program code, the computer program code comprising computer instructions, and the one or more processors calling the computer instructions so that the electronic device executes the method described in the first aspect or any possible implementation of the first aspect.

[0018] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, which includes a computer program or instructions. When the computer program or instructions are run on a computer, the computer executes the method described in the first aspect or any possible implementation of the first aspect.

[0019] In a sixth aspect, an embodiment of the present application provides a computer program product, which includes a computer program code. When the computer program code runs on a computer, it enables the computer to execute the method described in the first aspect or any possible implementation of the first aspect.

[0020] In a seventh aspect, the present application provides a chip or chip system, comprising one or more processors and a communication interface, wherein the communication interface and the one or more processors are interconnected by a line, and the one or more processors are configured to run a computer program or instruction to perform the method described in the first aspect or any possible implementation of the first aspect. The communication interface in the chip may be an input / output interface, a pin, or a circuit.

[0021] In one possible implementation, the chip or chip system described above in this application further includes at least one memory, wherein instructions are stored in the at least one memory. The memory may be a storage unit within the chip, such as a register or cache, or a storage unit of the chip (such as a read-only memory or random access memory).

[0022] It should be understood that the second to sixth aspects of the present application correspond to the technical solutions of the first aspect of the present application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a digital predistortion system provided in an embodiment of the present application;

[0024] Figure 2 A schematic diagram of a baseband signal provided in an embodiment of the present application;

[0025] Figure 3 A schematic diagram of a signal output by a conventional digital predistortion system provided in an embodiment of the present application;

[0026] Figure 4 A schematic flow chart of a method for processing basis functions of a frequency-offset band-limited digital predistorter provided in an embodiment of the present application;

[0027] Figure 5 A schematic diagram of a process for processing a baseband signal by a frequency-offset band-limited digital predistorter provided in an embodiment of the present application;

[0028] Figure 6 A schematic flow chart of another method for processing basis functions of a frequency-offset band-limited digital predistorter provided in an embodiment of the present application;

[0029] Figure 7 A schematic diagram of another process for processing a baseband signal by a frequency-offset band-limited digital predistorter provided in an embodiment of the present application;

[0030] Figure 8 A schematic diagram of a signal processed by a frequency-offset band-limited digital predistorter provided in an embodiment of the present application;

[0031] Figure 9 A schematic diagram of a signal output by a frequency-offset, band-limited digital predistortion system provided in an embodiment of the present application;

[0032] Figure 10 A schematic flow chart of a frequency-offset band-limited digital predistortion method provided in an embodiment of the present application;

[0033] Figure 11 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application;

[0034] Figure 12 A schematic diagram of a chip structure provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] To facilitate a clear description of the technical solutions of the embodiments of the present application, some of the terms and technologies involved in the embodiments of the present application are briefly introduced below:

[0036] 1. Terminology

[0037] In the embodiments of this application, terms such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. For example, the terms "first chip" and "second chip" are used solely to distinguish between different chips and do not define their order. Those skilled in the art will understand that terms such as "first" and "second" do not define the quantity or execution order, and do not necessarily define differences.

[0038] It should be noted that in the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0039] In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or plural.

[0040] 2. Electronic devices

[0041] The electronic devices of the embodiments of the present application may include handheld devices with wireless communication functions, vehicle-mounted devices, etc. For example, some electronic devices include: mobile phones, tablet computers, PDAs, laptop computers, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, in-vehicle devices, wearable devices, electronic devices in 5G networks or future evolved public land mobile communication networks (PLMNs), and other devices. The embodiments of the present application do not limit this.

[0042] As an example and not a limitation, in the embodiments of the present application, the electronic device may also be a wearable device. Wearable devices may also be referred to as wearable smart devices, which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are fully functional, large in size, and can achieve complete or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0043] In addition, in the embodiments of the present application, the electronic device may also be an electronic device in the Internet of Things (IoT) system. The IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network that interconnects people and machines and things.

[0044] The electronic device in the embodiments of the present application may also be referred to as: electronic device, user equipment (UE), mobile station (MS), mobile terminal (MT), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent or user device, etc.

[0045] In an embodiment of the present application, an electronic device includes a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on top of the operating system layer. The hardware layer includes hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also known as main memory). The operating system can be any one or more computer operating systems that implement business processing through processes, such as the Linux operating system, Unix operating system, Android operating system, iOS operating system, or Windows operating system. The application layer includes applications such as browsers, address books, word processing software, and instant messaging software.

[0046] 3. Digital Pre-Distortion (DPD)

[0047] Digital pre-distortion (DPD) is a signal processing technique used to improve the linearity of power amplifiers (PAs). In wireless communication devices, power amplifiers (PAs) amplify radio frequency signals for long-distance transmission. However, PAs typically exhibit nonlinear characteristics, meaning that as the input signal power increases, the linear relationship between the output signal and the input signal gradually deteriorates, resulting in signal distortion. DPD algorithms pre-process the signal before the PA, introducing a distortion that is opposite to the PA's nonlinear characteristics. This results in a more linearly amplified signal at the PA output.

[0048] 4. Band-limited digital predistortion

[0049] Bandlimiting refers to bandwidth restriction. Bandlimited predistortion (DPD) applies digital predistortion (DPD) to limit the signal's bandwidth. This technique not only considers the nonlinear distortion of the power amplifier but also the signal's spectral characteristics. During processing, DPD limits the signal's bandwidth to ensure minimal distortion within a specific bandwidth.

[0050] 5. Frequency-offset band-limited digital predistortion

[0051] Frequency offset refers to frequency shift. Frequency-offset band-limited digital predistortion (DPD) takes the frequency offset characteristics of the signal into account, building upon BLD DPD. This technology not only limits the signal's bandwidth but also compensates for its frequency offset. During processing, DPD considers the power amplifier's nonlinear distortion, the signal's bandwidth limitations, and frequency offset compensation simultaneously to ensure signal stability and accuracy during transmission.

[0052] Figure 1 The following is an example of a digital predistortion system block diagram. Figure 1 As shown, the digital predistortion system may include a digital predistorter, a digital-to-analog converter, a modulator, a power amplifier, a filter 1, a coupler, a demodulator, an analog-to-digital converter, and a digital predistortion training module.

[0053] In some implementations, the filter 1 may also be referred to as a radio frequency filter.

[0054] When the system is in a training process (training refers to training of a digital predistortion model, the purpose of which is to obtain coefficients of the model), the digital predistorter in the system may not work, or the system may not include a digital predistorter.

[0055] The baseband digital signal is input into the path formed by the digital-to-analog converter, modulator, power amplifier, filter 1, and coupler. After the baseband digital signal is converted from a baseband digital signal to an analog signal by the digital-to-analog converter, it is modulated into a radio frequency signal by the modulator. The modulator outputs the radio frequency signal to the power amplifier. Then, the distorted signal output by the power amplifier is filtered out of excess frequency bands by filter 1, and then input into the feedback path through the coupler. In the feedback path, it is converted into a baseband digital signal by the demodulator and the analog-to-digital converter. The baseband digital signal at this time is input into the digital pre-distortion training module to understand the distortion of the signal output by the power amplifier after filtering out part of the frequency band by filter 1. Then, the digital pre-distortion training module outputs the effective coefficient of the digital pre-distortion model to the digital pre-distorter based on the original baseband digital signal and the distortion of the baseband digital signal.

[0056] When the system is applied (the application of the system means that the digital predistortion model in the digital predistorter has included effective coefficients), the baseband digital signal (e.g. Figure 2 As shown) is input into the path formed by the digital predistorter, digital-to-analog converter, modulator, power amplifier, filter 1, and coupler. The digital predistorter is used to perform predistortion processing on the signal before entering the power amplifier based on the digital predistortion model, so that the processed signal can present a linear relationship with the original signal (referring to the baseband digital signal entering the digital predistortion processor) after passing through the power amplifier (the signal after predistortion processing and then processed by the power amplifier and output by the filter 1 can be, for example, as shown). Figure 3 ), in order to reduce the signal distortion problem caused by the nonlinear characteristics of the power amplifier.

[0057] The coupler can distribute the input signal to multiple output ports. The signal output by the coupler is transmitted through the antenna port on the one hand, and is also output to the feedback path including the demodulator, analog-to-digital converter and digital pre-distortion training module on the other hand. In addition to being used to feed back the distorted signal from the power amplifier, the feedback path can also be used for power control. Therefore, the coupler needs to be placed as close to the antenna as possible to ensure that the antenna can stably output a signal of appropriate strength to avoid communication problems caused by excessively strong or weak signals.

[0058] Optionally, when the system is in application, the digital pre-distortion training module can be used to verify whether the output signal is distorted.

[0059] exist Figure 1 In the system shown, filter 1 is designed to limit the output signal's bandwidth to the useful frequency band, preventing it from impacting other channels. However, this also means that the distorted signal collected by the feedback path is not the complete distorted signal output by the power amplifier. Therefore, the predistortion model trained based on this signal may have insufficient correction capabilities for the original signal (the signal entering the predistortion processor), or even further degrade it.

[0060] Furthermore, because the center frequency of the signal transmitted by the terminal device is not fixed, frequency deviation (also known as frequency offset, which can be understood as the inconsistency between the center frequency of the transmitted signal and the center frequency of the filter) may occur, and filter 1 always filters out signals in a fixed frequency band. In the case of frequency offset, the filtering range of filter 1 for useful distorted signals is different, affecting the training effect of the digital pre-distortion model. Therefore, the researchers of this application believe that considering the frequency offset when training the digital pre-distortion model is beneficial to improving the correction capability of the digital pre-distortion system.

[0061] In view of this, embodiments of the present application provide a frequency-offset, band-limited digital predistortion method, system, electronic device, chip system, storage medium, and program product. These methods can be applied to a frequency-offset, band-limited digital predistortion system including a frequency-offset, band-limited digital predistorter and filter 1 (equivalent to the first filter described below). The frequency-offset, band-limited digital predistorter obtains a first baseband signal (equivalent to the baseband digital signal or original signal described below), determines a first frequency offset value (equivalent to difference 1 described below), uses a first set of basis functions constructed in the frequency-offset, band-limited digital predistorter based on the first frequency offset value as functions for processing the first baseband signal, uses a first set of distortion coefficients corresponding to the first set of basis functions as distortion coefficients for processing the first baseband signal, and outputs a first processing result for the first baseband signal. In the method provided in embodiments of the present application, the frequency-offset, band-limited digital predistorter can determine and select corresponding basis functions and distortion coefficients based on the first frequency offset value, thereby improving the processing accuracy of the frequency-offset, band-limited digital predistorter.

[0062] Furthermore, in the frequency-offset band-limited digital predistortion method, the basis function of the frequency-offset band-limited digital predistortion model used is processed by frequency conversion and filtering. On the one hand, the frequency-offset band-limited digital predistorter involved in the embodiment of the present application uses a band-limited basis function (for example, the frequency-offset band-limited digital predistorter includes a filter) to match the distortion of the power amplifier and the first filter to achieve a better correction effect. On the other hand, the training of the frequency-offset band-limited digital predistortion model used by the frequency-offset band-limited digital predistorter in the embodiment of the present application takes into account Figure 1 The offset between the center frequency of the transmitted signal and the center frequency of the filter in the shown system, and the positional relationship between the center frequency of the basis function in the frequency-offset band-limited digital predistortion model and the center frequency of the filter (which can be understood as the second filter (Filter 2) or the third filter (Filter 3) described below) need to be consistent with the positional relationship between the center frequency of the transmitted signal and the center frequency of the first filter, which is beneficial to improving the correction capability of the system.

[0063] The basis functions included in the frequency offset band limited digital predistorter can be understood as a frequency offset band limited digital predistortion model.

[0064] It should be noted that the digital predistorter in the digital predistortion system that has the above-mentioned technical problems in the related art can be called a traditional digital predistorter, the digital predistortion training module can be called a traditional digital predistortion training module, and its corresponding model can be called a traditional digital predistortion model. In the case of implementing the embodiment of the present application, the digital predistorter in the digital predistortion system can be understood as a frequency deviation band-limited digital predistorter, the digital predistortion training module can be understood as a frequency deviation band-limited digital predistortion training module, and its corresponding model is a frequency deviation band-limited digital predistortion model, which will not be explained again later. Figure 1When the digital predistorter is a frequency deviation band-limited digital predistorter, the digital predistortion training module is a frequency deviation band-limited digital predistortion training module, and the corresponding model is a frequency deviation band-limited digital predistortion model, the embodiment of the present application can be applied to the digital predistortion system, which is referred to as a "frequency deviation band-limited digital predistortion system" hereinafter.

[0065] It is worth noting that the traditional digital predistortion system can also be considered as a zero-frequency offset band-limited digital predistortion system, that is, the traditional digital predistortion system can be understood as a special case of the frequency offset band-limited digital predistortion system, but in this application, this type of predistortion system is still referred to as a traditional digital predistortion system.

[0066] The method provided in the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0067] Figure 4 A schematic flow chart of a method 400 for processing basis functions of a frequency-offset band-limited digital predistorter provided in an embodiment of the present application is exemplarily shown.

[0068] The method 400 may include the following steps:

[0069] S401. Construct basis function 1.

[0070] It should be understood that the construction of the basis function is related to the nonlinear characteristics of the power amplifier. Optionally, the more severe the nonlinearity of the power amplifier, the more complex the basis function, and / or the higher the accuracy of the digital predistortion system, the more complex the basis function, but this application does not specifically limit this.

[0071] In some implementations, the basis function may be a memory polynomial (MP), a generalized memory polynomial (GMP), or a dynamic deviation reduction (DDR) model, etc., which is not limited in this application.

[0072] S402 : Perform a first frequency conversion process on basis function 1 to obtain basis function 2 after the first frequency conversion.

[0073] It should be understood that the frequency conversion experienced by the basis function corresponds to the frequency deviation between the center frequency of the signal modulated by the modulator and the center frequency of the filter set in the digital predistortion system, and the frequency value offset by the basis function is the difference 1 between the center frequency of the signal modulated by the modulator and the center frequency of the filter 1 set in the digital predistortion system.

[0074] Since the digital predistorter processes baseband digital signals, which are low-frequency signals concentrated near zero frequency, and the basis function is the digital predistortion model function in the digital predistorter, the frequency conversion of the basis function can be understood as upward conversion (in the direction of increasing frequency) or downward conversion (in the direction of decreasing frequency) starting from zero frequency. In other words, if the difference value 1 is greater than zero, the basis function is subjected to upward frequency conversion processing, so that the relative position of the center frequency of the baseband digital signal processed by the basis function and the center frequency of filter 2 set in the digital predistortion model in the embodiment of the present application are consistent with the relative position of the center frequency of the signal modulated by the modulator and the center frequency of filter 1 set in the digital predistortion system. Similarly, if the difference value 1 is less than zero, the basis function is subjected to downward frequency conversion processing.

[0075] S403 , pass basis function 2 through filter 2 to obtain basis function 3.

[0076] In some implementations, filter 2 is a low-pass filter. Filter 2 may have the same bandwidth and a similar shape as filter 1. Thus, since distorted signals outside the bandwidth of filter 1 will be suppressed by filter 1, in the embodiment of the present application, the bandwidth of the signal output from the digital predistorter at the digital predistorter stage is consistent with the bandwidth of filter 1 through which the signal subsequently passes. Therefore, there is no need to predistort signals outside this bandwidth in the digital predistorter.

[0077] S404 , performing a second frequency conversion process on basis function 3 to obtain basis function 4. The direction of the second frequency conversion process is opposite to that of the first frequency conversion process.

[0078] It should be understood that the first frequency conversion process and the second frequency conversion process are in opposite directions, but the absolute frequency difference of the offset is the same. In this way, it can be ensured that the center frequency of the signal processed based on basis function 4 is still zero frequency, which is convenient for subsequent frequency modulation processing.

[0079] Exemplarily, the frequency value shifted by the second frequency conversion process may be a difference 2 between the center frequency of the filter 1 set in the digital predistortion system and the center frequency of the signal modulated by the modulator, where the difference 2=-the difference 1.

[0080] The basis function processing process described in the above method 400 is described in detail below through specific formula examples.

[0081] For example, the basis function 1 constructed in the above S401 may be the following formula (1).

[0082] (1)

[0083] in, For example, it can be MP, and its formula can be, for example: , M can be understood as the memory depth, K can be understood as the nonlinear order, the values of M and K are related to the performance of the power amplifier, and n can be understood as the nth signal in the signal sample sequence. For example it could be , but this application does not limit this.

[0084] The first frequency conversion process in the above S402 can be for The basis function 2 can be written as , in some implementations, the formula of basis function 2 can be the following formula (2).

[0085] (2)

[0086] in, Represents the above difference 1, that is, the frequency offset, Indicates the sampling rate.

[0087] In the above S403, the basis function 2 is processed by the filter 2 to obtain the basis function 3 which can be recorded as , its formula can be as follows (3).

[0088] (3)

[0089] in, is the coefficient of filter 2, and L is the order of filter 2.

[0090] Furthermore, the above basis function 4 can be expressed as , basis function 4 is obtained by performing the second frequency conversion processing on basis function 3, and the formula of basis function 4 can be the following formula (4).

[0091] (4)

[0092] So far, it can be considered that the basis function 4 is a basis function that can be used for the frequency deviation band-limited digital predistorter described in the embodiment of the present application. Further, the embodiment of the present application can also be based on Figure 1 A similar frequency-offset, band-limited digital predistortion system uses the training process described above to obtain a distorted signal from a feedback channel. Then, based on the distorted signal and the baseband digital signal used in the training process, as well as the frequency-offset, band-limited digital predistortion model constructed using basis function 4, the distortion coefficients of the frequency-offset, band-limited digital predistortion model are obtained.

[0093] It should be noted that in some implementations, in S401 above, basis function 1 may include multiple different sub-functions (different sub-functions may represent different processing precisions). Each sub-function is processed using the steps shown in method 400 above. The resulting basis function 4 also includes multiple sub-functions corresponding to basis function 1. Therefore, the distortion coefficients corresponding to the frequency-offset, band-limited predistortion model trained using basis function 4 may also include multiple values. The subscript p in each of the above formulas may include 1, 2, 3, ..., P, where P may represent the number of distortion coefficients (or the number of sub-functions) corresponding to the frequency-offset, band-limited predistortion model.

[0094] In addition, the embodiment of the present application can also be used for different frequency deviations (i.e., the above difference 1, i.e., the above formulas (2) and (4) ) to obtain different basis functions 4, and then, based on each sub-function in the different basis functions 4, obtain a corresponding set of distortion coefficients corresponding to the sub-functions. For example, training the basis function 4 obtained for frequency offset 1 obtains a set of distortion coefficients, while training the basis function 4 obtained for frequency offset 2 obtains another set of distortion coefficients. The number of distortion coefficients in each set can be the same or different, and this application does not specifically limit this. Optionally, the number of distortion coefficients in each set can be related to the number of sub-functions in the corresponding basis function.

[0095] Taking the number of distortion coefficients corresponding to the frequency offset band-limited predistortion model obtained by training based on basis function 4 as P as an example, the processing flow of the signal to be sent by the electronic device by the frequency offset band-limited predistorter obtained based on the model can be as follows: Figure 5 As shown.

[0096] Figure 5 FIG. 4 shows the working process of the frequency deviation band-limited digital predistorter provided by the embodiment of the present application. Figure 5 As shown, after the baseband digital signal is input into the frequency deviation band limited digital predistorter, the frequency deviation band limited digital predistorter can first determine the difference between the center frequency of the baseband digital signal modulated by the modulator and the center frequency of the filter 1 set in the digital predistortion system. , based on this Determine and select the corresponding use of this The constructed basis function is then processed by the first frequency conversion based on the basis function, and then the excess bandwidth is filtered through filter 2. After the second frequency conversion, it is multiplied by the distortion coefficient corresponding to the basis function. Since the basis function contains P sub-functions, the baseband digital signal is input into the P sub-functions for processing and the results of multiplication with the distortion coefficients of each sub-function are accumulated as the output of the frequency-deviation band-limited digital predistorter.

[0097] For example, in combination with the above formula (4), the formula for the output result of the frequency-offset band-limited digital predistorter provided in the embodiment of the present application may be the following formula (5).

[0098] (5)

[0099] Where P is the number of distortion coefficients, is the value of the p-th distortion coefficient.

[0100] It should be understood that since the filter 2 in the frequency-offset band-limited digital predistorter has the same bandwidth as the filter 1 after the power amplifier in the frequency-offset band-limited digital predistortion system, that is, the frequency-offset band-limited digital predistortion model is trained for the bandwidth intercepted by the filter 1 and does not involve the filtered bandwidth portion, which can ensure that the bandwidth intercepted by the frequency-offset band-limited predistorter is the same as the bandwidth intercepted by the filter 1. In addition, due to the double frequency conversion processing, the frequency-offset band-limited digital predistorter also performs frequency offset processing on the baseband digital signal so that the center frequency of the signal modulated by the modulator is the same as the center frequency of the filter 1 provided in the digital predistortion system. The distorted signal obtained based on this frequency-offset band-limited digital predistorter corrects the frequency offset of the distorted signal obtained based on the feedback channel, which is beneficial to improving the frequency-offset band-limited digital predistorter's ability to correct the nonlinearity of the power amplifier.

[0101] Figure 6 A schematic flow chart of another method 600 for processing basis functions of a frequency-offset band-limited digital predistorter provided in an embodiment of the present application is exemplarily shown.

[0102] The method 600 may include the following steps:

[0103] S601 is similar to the above-mentioned S401 and will not be described in detail.

[0104] S602 : Process basis function 1 based on filter 3 to obtain basis function 5.

[0105] Optionally, filter 3 can be a bandpass filter, whose center frequency can be the difference 2 between the center frequency of filter 1 set in the digital predistortion system and the center frequency of the signal modulated by the modulator. Filter 3 can have the same bandwidth and a similar shape as filter 1, but this application does not make any specific limitations on this.

[0106] The difference between S402-S404 and S602 can be understood as follows: after processing by S402, basis function 1 can shift the center frequency of the input baseband digital signal to achieve frequency conversion; while S602 can be understood as the fact that after processing by S602, basis function 1 shifts the center frequency of filter 3, through which the input baseband digital signal passes. It should be understood that for the same baseband digital signal, the results obtained after processing by S402-S404 and S602 are the same.

[0107] For example, the basis function 1 constructed in the above S601 can also be expressed as the above formula (1), and the basis function 5 obtained based on the above S602 can be expressed as , its formula can be, for example, the following formula (6).

[0108] (6)

[0109] in, is the coefficient of filter 3, L is also the order of filter 3, ,visible, With the above They can be the same when n and l have the same value.

[0110] Furthermore, based on Figure 1 A similar frequency-offset, band-limited digital predistortion system utilizes the training process described above to obtain a distorted signal from a feedback channel. Then, based on the distorted signal, the baseband digital signal used in the training process, and the frequency-offset, band-limited digital predistortion model constructed using basis function 5, the distortion coefficients of the frequency-offset, band-limited digital predistortion model are obtained. It should be understood that basis function 5 may also include multiple sub-functions corresponding to basis function 1. Therefore, the distortion coefficients corresponding to the frequency-offset, band-limited digital predistortion model trained using basis function 5 may also include multiple sub-functions.

[0111] Taking the number of distortion coefficients corresponding to the frequency offset band-limited predistortion model obtained by training based on basis function 5 as P as an example, the processing flow of the signal to be sent by the electronic device by the frequency offset band-limited predistorter obtained based on the model can be as follows: Figure 7 As shown.

[0112] Figure 7 FIG. 2 shows the working process of another frequency deviation band-limited digital predistorter provided by an embodiment of the present application. Figure 7 As shown, after the baseband digital signal is input into the frequency deviation band limited digital predistorter, the frequency deviation band limited digital predistorter can first determine the difference between the center frequency of the baseband digital signal modulated by the modulator and the center frequency of the filter 1 set in the digital predistortion system. , based on this Determine and select the corresponding use of this The constructed basis function is then based on the basis function (which can also be understood as selecting The baseband digital signal passes through filter 3 and is multiplied by the distortion coefficient. Since the basis function contains P sub-functions, the baseband digital signal is input into each of the P sub-functions for processing, and the result of multiplication by the distortion coefficient of each sub-function is accumulated as the output of the frequency-offset band-limited digital predistorter. The formula for the output result can be referred to the above formula (5) and will not be repeated here.

[0113] The beneficial effects of this embodiment are similar to those of the above Figure 5 The embodiments are similar and will not be described in detail.

[0114] In one implementation, Figure 2 After the signal shown is processed by the frequency deviation band limited digital predistortion system described in the embodiment of the present application, its output can be as follows Figure 8 As shown, the signal is further processed by the power amplifier and the filter 1, and the relationship between the frequency and the power spectral density (PSD) of the signal output from the filter can be as follows: Figure 9 As shown, Figure 9 and Figure 3 In comparison, the signal sideband power spectral density is smaller and closer to Figure 2 From the original signal shown, it can be seen that the frequency-offset band-limited digital predistortion system provided by the embodiment of the present application has an improved capability of correcting the nonlinear distortion of the power amplifier compared to the traditional digital predistortion system.

[0115] Figure 10 The frequency deviation band-limited digital predistortion method 1000 provided in an embodiment of the present application is shown. The method can be applied to an electronic device including a frequency deviation band-limited digital predistortion system. The hardware structure of the electronic device can be Figure 11 The frequency-offset band-limited digital predistortion system includes a frequency-offset band-limited digital predistorter and a first filter. The frequency-offset band-limited digital predistorter includes at least one set of basis functions and a set of distortion coefficients corresponding to each of the at least one set of basis functions. Method 1000 includes:

[0116] S1001. A frequency-offset band-limited digital predistorter obtains a first baseband signal and determines a first frequency offset value, where the first frequency offset value is a difference between a center frequency of a radio frequency signal corresponding to the first baseband signal and a center frequency of a first filter.

[0117] S1002. The frequency-offset-band-limited digital predistorter uses a first group of basis functions constructed based on a first frequency offset value from at least one group of basis functions as functions for processing a first baseband signal, and uses a first group of distortion coefficients corresponding to the first group of basis functions as distortion coefficients for processing the first baseband signal; the first group of distortion coefficients is obtained by training the first group of basis functions based on a distortion signal collected by the frequency-offset-band-limited digital predistortion system and a baseband signal corresponding to the distortion signal.

[0118] S1003. The frequency-device-band-limited digital predistorter outputs a first processing result for the first baseband signal; the first processing result includes: a cumulative result of multiplying a second processing result of each basis function in the first group of basis functions on the first baseband signal by a distortion coefficient corresponding to each basis function.

[0119] The first baseband signal may refer to a signal obtained when the frequency-offset band-limited digital predistortion system is in an application scenario, and may have similar meanings to the baseband digital signal, original signal, etc. described above in the same scenario.

[0120] The first filter can be understood as a filter for processing radio frequency signals in a frequency-offset band-limited digital predistortion system, and can be equivalent to the filter 1 described above, but this application does not make any specific limitation to this.

[0121] The first frequency offset value may have a similar meaning to the difference value 1 described in the above method 400 .

[0122] In the method provided in an embodiment of the present application, a frequency-offset-band-limited digital predistorter considers the center frequency offset of the RF signal corresponding to the first baseband signal during processing of the first baseband signal. Since this offset may cause the subsequent first filter to filter the RF signal in a different range each time, further affecting the entire system's ability to correct the distorted signal, in this embodiment of the present application, the frequency-offset-band-limited digital predistorter can determine and select corresponding basis functions and distortion coefficients based on the first frequency offset value to ensure that the center frequency offset of the first baseband signal processed by the frequency-offset-band-limited digital predistorter is consistent with the offset of the corresponding RF signal. This helps ensure that the subsequent first filter maintains a consistent filtering range for each input RF signal. This means that the frequency-offset-band-limited digital predistorter system can obtain distorted signals with a consistent filtering range in training scenarios. The distortion coefficients obtained through training on this basis are more reliable, which helps improve the processing accuracy and reliability of the frequency-offset-band-limited digital predistorter.

[0123] In the above method 1000, the processing of the first baseband signal by the frequency-offset, band-limited digital predistorter based on each basis function in the first group of basis functions includes the following two possible implementations.

[0124] In a first implementation, the frequency-offset band-limited digital predistorter includes a second filter, and the bandwidth of the second filter is the same as that of the first filter. In the above-mentioned method 1000, the frequency-offset band-limited digital predistorter processes the first baseband signal based on each basis function in the first group of basis functions, including: performing a first frequency conversion process on the first baseband signal to obtain a second baseband signal, and the absolute difference between the center frequency of the second baseband signal and the center frequency of the first baseband signal is a first frequency offset value; passing the second baseband signal through a second filter to obtain a third baseband signal; performing a second frequency conversion process on the third baseband signal to obtain a fourth baseband signal, and the second processing result includes the fourth baseband signal, the second frequency conversion process and the first frequency conversion process have opposite frequency offset directions, and the absolute difference between the center frequency of the fourth baseband signal and the center frequency of the third baseband signal is the first frequency offset value.

[0125] In an embodiment of the present application, the first frequency conversion processing causes the frequency-shifted band-limited digital predistorter to perform a frequency shift on the first baseband signal to obtain a second baseband signal. The frequency shift is the same as the frequency shift of the center frequency of the corresponding RF signal and the center frequency of the first filter. On this basis, the second baseband signal is filtered using a second filter with the same bandwidth as the first filter. The resulting third baseband signal has the same signal segment as the RF signal subsequently processed by the first filter. The fourth baseband signal obtained by the second frequency conversion processing is then at the same zero-frequency position as the first baseband signal to ensure that the first baseband signal maintains its original frequency after processing. This is beneficial for correcting the influence of the frequency offset of the RF signal on the frequency-shifted band-limited digital predistorter and for improving the frequency-shifted band-limited digital predistorter's ability to correct the nonlinearity of the power amplifier.

[0126] Furthermore, the frequency-offset band-limited digital pre-distorter includes a second filter, which has the same bandwidth as the first filter. That is, the frequency-offset band-limited digital pre-distorter is trained for the bandwidth intercepted by the first filter and does not involve the filtered bandwidth part, which is conducive to saving the computing power of the frequency-offset band-limited digital pre-distorter and ensuring its accuracy.

[0127] The basis functions obtained in the above method 400 can be understood to include the first set of basis functions used in this embodiment. That is, each basis function in the first set of basis functions used in the embodiment of the present application can be processed similarly to the above method 400. The formula of each basis function in the first set of basis functions can be expressed as the above formula (4), and the second processing result can be obtained according to formula (4). Furthermore, the first processing result can be obtained based on the above formula (5).

[0128] Optionally, the second filter is a low-pass filter.

[0129] In a second implementation, the frequency-offset band-limited digital predistorter includes a third filter, and the bandwidth of the third filter is the same as that of the first filter. The frequency-offset band-limited digital predistorter processes the first baseband signal based on each basis function in the first group of basis functions, including: passing the first baseband signal through the third filter to obtain a fifth baseband signal, the second processing result includes the fifth baseband signal, the center frequency of the third filter is a second frequency offset value, and the second frequency offset value is the inverse of the first frequency offset value.

[0130] The second frequency offset value can be understood as the difference 2 described above.

[0131] In an embodiment of the present application, the frequency-deviation band-limited digital predistorter includes a third filter, whose center frequency is the second frequency offset value. In this way, the fifth baseband signal obtained by passing the first baseband signal through the third filter has the same signal segment as the radio frequency signal subsequently processed by the first filter, which is beneficial to correcting the influence of the frequency deviation of the radio frequency signal on the frequency-deviation band-limited digital predistorter, and is beneficial to improving the frequency-deviation band-limited digital predistorter's ability to correct the nonlinearity of the power amplifier.

[0132] It should be understood that the difference between the second implementation method and the first implementation method is that the first implementation method is to change the position of the center frequency of the first baseband signal so that after passing through the second filter, it can obtain a signal segment that is the same as the RF signal subsequently processed by the first filter, while the second implementation method is to set the center frequency of the third filter so that the signal processed by the third filter has the same signal segment as the RF signal subsequently processed by the first filter.

[0133] The basis functions obtained in the above method 600 can be understood to include the first set of basis functions used in this embodiment, that is, each basis function in the first set of basis functions used in the embodiment of the present application can be processed similarly to the above method 600. The formula of each basis function in the first set of basis functions can be expressed as the above formula (6), and the second processing result can be obtained according to formula (6). In one implementation, formula (6) has the same meaning as formula (4). Furthermore, the first processing result can also be obtained based on the above formula (5).

[0134] Optionally, the third filter is a bandpass filter.

[0135] As an optional embodiment, each of the at least one group of basis functions is one or more of a memory polynomial, a generalized memory polynomial, or a dynamic deviation reduction model.

[0136] The frequency-offset, band-limited digital predistortion method according to an embodiment of the present application has been described above. The following describes an apparatus for performing the above method provided in an embodiment of the present application. Those skilled in the art will appreciate that the method and apparatus may be combined and referenced with one another, and that the relevant apparatus provided in an embodiment of the present application may perform the steps of the above method.

[0137] The frequency deviation band-limited digital predistortion method provided in the embodiment of the present application can be applied to electronic devices with communication functions. The hardware structure of the electronic device can be as follows: Figure 11 As shown in , the specific form of the electronic device can refer to the above description and will not be repeated here.

[0138] To facilitate understanding of the embodiments of the present application, the hardware structure of the electronic device provided in the embodiments of the present application is introduced below.

[0139] Figure 11 A schematic diagram of the hardware structure of an electronic device is shown.

[0140] The electronic device 1100 may include a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display screen 194, and a subscriber identification module (SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity light sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, etc.

[0141] It should be understood that the structures illustrated in the embodiments of the present application do not constitute a specific limitation on the electronic device 1100. In other embodiments of the present application, the electronic device 1100 may include more or fewer components than shown, or may combine or separate certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0142] The wireless communication function of the electronic device 1100 can be implemented through the antenna 1, the antenna 2, the mobile communication module 150, the wireless communication module 160, the modem processor and the baseband processor.

[0143] Antenna 1 and Antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in electronic device 1100 can be used to cover a single or multiple communication frequency bands. Different antennas can also be reused to improve antenna utilization. For example, antenna 1 can be reused as a diversity antenna for a wireless local area network. In other embodiments, the antennas can be used in conjunction with a tuning switch.

[0144] The mobile communication module 150 can provide wireless communication solutions including 2G / 3G / 4G / 5G applied on the electronic device 1100.

[0145] The wireless communication module 160 can provide wireless communication solutions applied to the electronic device 1100, including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), infrared technology (IR), etc.

[0146] In some implementations, the frequency deviation and band-limited predistortion system involved in the embodiments of the present application may be included in the mobile communication module 150 and / or the wireless communication module 160, or may be coupled with the mobile communication module 150 and / or the wireless communication module 160 to implement functions, but the present application does not make specific limitations on this.

[0147] Figure 12 The schematic diagram of the structure of a chip provided by the embodiment is exemplarily shown. The chip 1200 includes one or more (including two) processors 1201 , a communication line 1202 , a communication interface 1203 and a memory 1204 .

[0148] In some embodiments, the memory 1204 stores the following elements: executable modules or data structures, or a subset thereof, or an extended set thereof.

[0149] The methods described in the above embodiments of the present application can be applied to the processor 1201 or implemented by the processor 1201. The processor 1201 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be completed by a hardware integrated logic circuit in the processor 1201 or by instructions in the form of software. The above processor 1201 can be a general-purpose processor (for example, a microprocessor or a conventional processor), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gates, transistor logic devices, or discrete hardware components. The processor 1201 can implement or execute the methods, steps, and logic block diagrams related to each process disclosed in the embodiments of the present application.

[0150] The steps of the method disclosed in the embodiments of this application can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium well-established in the art, such as random access memory, read-only memory, programmable read-only memory, or electrically erasable programmable read-only memory (EEPROM). The storage medium is located in memory 1204, and processor 1201 reads the information in memory 1204 and, in conjunction with its hardware, completes the steps of the method described above.

[0151] The processor 1201 , the memory 1204 , and the communication interface 1203 can communicate with each other via the communication line 1202 .

[0152] In the above embodiment, the instructions stored in the memory for execution by the processor may be implemented in the form of a computer program product, wherein the computer program product may be pre-written in the memory or downloaded and installed in the memory in the form of software.

[0153] In the embodiment of the present application, the chip 1200 may also be a chip system, such as a system on chip (SOC), which is not limited in the present application.

[0154] An embodiment of the present application provides a frequency-offset-band-limited digital predistortion system, including a first path formed by a frequency-offset-band-limited digital predistorter, a digital-to-analog converter, a modulator, a power amplifier, a first filter, and a coupler; and a second path formed by the digital-to-analog converter, a modulator, a power amplifier, a first filter, a coupler, a demodulator, an analog-to-digital converter, and a frequency-offset-band-limited digital predistortion training module. When the frequency-offset-band-limited digital predistortion system is in an application scenario, the frequency-offset-band-limited digital predistorter in the first path is used to implement each step of the above-mentioned method 1000. When the frequency-offset-band-limited digital predistortion system is in a training scenario, the second path is used to feed back a distortion signal and obtain distortion coefficients for the frequency-offset-band-limited digital predistorter based on training of the distortion signal.

[0155] An embodiment of the present application provides an electronic device, which includes a frequency-offset band-limited digital predistortion system.

[0156] An embodiment of the present application provides an electronic device, which includes: one or more processors and a memory; the memory is coupled to the one or more processors, the memory stores computer program code, and the computer program code includes computer instructions; the one or more processors call the computer instructions to enable the electronic device to execute the method in the above embodiment.

[0157] The present application provides a chip or chip system. The chip or chip system is applied to an electronic device and includes one or more processors configured to invoke computer instructions to cause the electronic device to execute the methods described in the above embodiments. The implementation principles and technical effects are similar to those of the above-described related embodiments and are not further elaborated here.

[0158] The embodiments of the present application also provide a computer-readable storage medium. The computer-readable storage medium includes computer instructions. When the computer instructions are executed on an electronic device, the electronic device executes the method in the above embodiment. The method described in the above embodiment can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. If implemented in software, the function can be stored as one or more instructions or codes on a computer-readable medium or transmitted on a computer-readable medium. Computer-readable media can include computer storage media and communication media, and can also include any medium that can transfer a computer program from one place to another. The storage medium can be any target medium that can be accessed by a computer.

[0159] In one possible implementation, computer-readable media may include RAM, ROM, compact disc read-only memory (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium designed to carry or store the desired program code in the form of instructions or data structures and accessible by a computer. Furthermore, any connection is appropriately termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include optical disc, laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks typically reproduce data magnetically, while optical discs reproduce data optically using lasers. Combinations of the above are also intended to be included within the scope of computer-readable media.

[0160] An embodiment of the present application provides a computer program product, which includes computer program code. When the computer program code runs on an electronic device, the electronic device executes the method in the above embodiment.

[0161] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processing unit of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable device to produce a machine, so that the instructions executed by the processing unit of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0162] The above specific implementation methods further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of the present invention should be included in the scope of protection of the present invention.

Claims

1. A frequency-offset band-limited digital predistortion method, characterized in that: The method is applied to a frequency-offset band-limited digital predistortion system, the frequency-offset band-limited digital predistortion system comprising a frequency-offset band-limited digital predistorter and a first filter, the frequency-offset band-limited digital predistorter comprising at least one set of basis functions and a set of distortion coefficients corresponding to each of the at least one set of basis functions, and comprising: The frequency-offset band-limited digital predistorter obtains a first baseband signal and determines a first frequency offset value, where the first frequency offset value is a difference between a center frequency of a radio frequency signal corresponding to the first baseband signal and a center frequency of the first filter; The frequency-offset-band-limited digital predistorter uses a first group of basis functions constructed based on the first frequency offset value among the at least one group of basis functions as functions for processing the first baseband signal, and uses a first group of distortion coefficients corresponding to the first group of basis functions as distortion coefficients for processing the first baseband signal; the first group of distortion coefficients is obtained by training the first group of basis functions based on a distortion signal collected by the frequency-offset-band-limited digital predistortion system and a baseband signal corresponding to the distortion signal; The frequency-device-band-limited digital predistorter outputs a first processing result of the first baseband signal; the first processing result includes: the cumulative result of multiplying the second processing result of each basis function in the first group of basis functions on the first baseband signal by the distortion coefficient corresponding to each basis function.

2. The method according to claim 1, characterized in that The frequency-offset-band-limited digital predistorter includes a second filter, wherein the second filter has the same bandwidth as the first filter; and the frequency-offset-band-limited digital predistorter processes the first baseband signal based on each basis function in the first group of basis functions, comprising: performing a first frequency conversion process on the first baseband signal to obtain a second baseband signal, where an absolute difference between a center frequency of the second baseband signal and a center frequency of the first baseband signal is the first frequency offset value; Passing the second baseband signal through the second filter to obtain a third baseband signal; A second frequency conversion process is performed on the third baseband signal to obtain a fourth baseband signal, where the second processing result includes the fourth baseband signal, the second frequency conversion process has a frequency offset in a direction opposite to that of the first frequency conversion process, and an absolute difference between a center frequency of the fourth baseband signal and a center frequency of the third baseband signal is the first frequency offset value.

3. The method according to claim 2, characterized in that The second filter is a low-pass filter.

4. The method according to claim 1, wherein The frequency-offset-band-limited digital predistorter includes a third filter, wherein the third filter has the same bandwidth as the first filter; and the frequency-offset-band-limited digital predistorter processes the first baseband signal based on each basis function in the first group of basis functions, comprising: The first baseband signal is passed through the third filter to obtain a fifth baseband signal, the second processing result includes the fifth baseband signal, the center frequency of the third filter is a second frequency offset value, and the second frequency offset value is the inverse of the first frequency offset value.

5. The method according to claim 4, characterized in that The third filter is a bandpass filter.

6. The method according to any one of claims 1 to 5, characterized in that Each of the at least one set of basis functions is one or more of a memory polynomial, a generalized memory polynomial, or a dynamic deviation reduction model.

7. A frequency-deviation band-limited digital predistortion system, characterized in that: A first path comprising a frequency deviation band limited digital predistorter, a digital-to-analog converter, a modulator, a power amplifier, a first filter, and a coupler, and a second path comprising a digital-to-analog converter, a modulator, a power amplifier, a first filter, a coupler, a demodulator, an analog-to-digital converter, and a frequency deviation band limited digital predistortion training module; When the frequency-offset-band-limited digital predistortion system is in an application scenario, the frequency-offset-band-limited digital predistorter in the first path is used to implement the method according to any one of claims 1 to 6; When the frequency offset band limited digital predistortion system is in a training scenario, the second path is used to feed back a distortion signal, and obtain distortion coefficients for the frequency offset band limited digital predistorter through training based on the distortion signal.

8. An electronic device, characterized in that: The electronic device comprises the frequency-offset band-limited digital predistortion system according to claim 7.

9. An electronic device, characterized in that: The electronic device includes: one or more processors and memory; The memory is coupled to the one or more processors, and the memory is used to store computer program code, where the computer program code includes computer instructions. The one or more processors call the computer instructions to enable the electronic device to execute the method according to any one of claims 1 to 6.

10. A chip system, characterized in that: The chip system is applied to an electronic device, and the chip system includes one or more processors, and the one or more processors are used to call computer instructions so that the electronic device executes the method as described in any one of claims 1 to 6.

11. A computer-readable storage medium, characterized in that The computer-readable storage medium comprises computer instructions, and when the computer instructions are executed on an electronic device, the electronic device is caused to perform the method according to any one of claims 1 to 6.

12. A computer program product, characterized in that The computer program product comprises a computer program code, and when the computer program code is run on an electronic device, the electronic device is caused to perform the method according to any one of claims 1 to 6.

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