CN113676217B - A digital predistortion correction method and device for frequency hopping communication - Google Patents

A digital predistortion correction method and device for frequency hopping communication Download PDF

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CN113676217B
CN113676217B CN202110989246.6A CN202110989246A CN113676217B CN 113676217 B CN113676217 B CN 113676217B CN 202110989246 A CN202110989246 A CN 202110989246A CN 113676217 B CN113676217 B CN 113676217B
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刘颖
夏翔杰
潘文生
徐强
邵士海
马万治
沈莹
唐友喜
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University of Electronic Science and Technology of China
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    • H—ELECTRICITY
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    • H—ELECTRICITY
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    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
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Abstract

The invention discloses a digital predistortion correction method and a device for frequency hopping communication, wherein the method comprises the following steps: s1, according to the working frequency range f of the frequency hopping system 1 ～f 2 The working frequency range is divided into K different frequency bands, and each frequency band adopts a group of digital predistortion coefficients: s2, for K groups of digital predistortion coefficient vectors c 1 ，c 2 ，…，c K Performing initialized coefficient extraction; s3, after the extraction of the initialization coefficient is completed, carrying out digital pre-distortion processing on the frequency hopping baseband signal; s4, after carrying out digital pre-distortion processing on the frequency hopping baseband signal, sending the frequency hopping baseband signal into a power amplifier for amplification, detecting the frequency spectrum of an output signal of the power amplifier, and entering a step S5 when the digital pre-distortion performance is deteriorated and exceeds a set index requirement; s5, for K groups of digital predistortion coefficient vectors c 1 ，c 2 ,…,c K And (4) updating. The group number of the predistortion coefficients adopted by the invention can be adjusted to be less than the frequency hopping frequency point number, thereby effectively reducing the complexity of digital predistortion correction.

Description

一种针对跳频通信的数字预失真校正方法与装置A digital predistortion correction method and device for frequency hopping communication

技术领域technical field

本发明涉及数字预失真技术，特别是涉及一种针对跳频通信的数字预失真校正方法与装置。The present invention relates to digital pre-distortion technology, in particular to a digital pre-distortion correction method and device for frequency hopping communication.

背景技术Background technique

跳频系统具有良好的抗干扰、抗多径、抗衰落特性。跳频系统的射频前端非线性器件，例如功放，会引入非线性失真，造成邻道干扰以及本信道通信的质量恶化。因此通常采用工作在数字基带的数字预失真(DPD)技术对功放的非线性失真进行抑制。但是在跳频通信系统中，功放工作在不同的跳频频点，对应的非线性失真特性也不同。一个跳频频点需要提取一组预失真系数，多个跳频也就需要提取多组预失真系数。当跳频系统的跳频频点增多时，需要提取的数字预失真系数组数也相应增加，这会提高系统复杂度。The frequency hopping system has good anti-jamming, anti-multipath and anti-fading characteristics. The RF front-end nonlinear devices of the frequency hopping system, such as power amplifiers, will introduce nonlinear distortion, causing adjacent channel interference and deterioration of communication quality in this channel. Therefore, the digital predistortion (DPD) technology working in the digital baseband is usually used to suppress the nonlinear distortion of the power amplifier. However, in a frequency hopping communication system, power amplifiers work at different frequency hopping frequencies, and the corresponding nonlinear distortion characteristics are also different. A set of pre-distortion coefficients needs to be extracted for one frequency hopping frequency point, and multiple sets of pre-distortion coefficients need to be extracted for multiple frequency hopping points. When the frequency hopping frequency points of the frequency hopping system increase, the number of digital predistortion coefficient groups to be extracted also increases correspondingly, which will increase the system complexity.

发明内容Contents of the invention

本发明的目的在于克服现有技术的不足，提供一种针对跳频通信的数字预失真校正方法与装置，采用的预失真系数的组数可以调整为少于跳频频点数，从而降低复杂度。The purpose of the present invention is to overcome the deficiencies of the prior art and provide a digital predistortion correction method and device for frequency hopping communication. The number of groups of predistortion coefficients used can be adjusted to be less than the number of frequency hopping points, thereby reducing complexity.

本发明的目的是通过以下技术方案来实现的：一种针对跳频通信的数字预失真校正方法，包括以下步骤：The purpose of the present invention is achieved by the following technical solutions: a digital predistortion correction method for frequency hopping communication, comprising the following steps:

S1.根据跳频系统的工作频率范围f1～f2，将工作频率范围划分为K个不同的频段，每个频段都采用一组数字预失真系数：S1. According to the operating frequency range f 1 ~ f 2 of the frequency hopping system, the operating frequency range is divided into K different frequency bands, and each frequency band adopts a set of digital predistortion coefficients:

设第k个频段占据的频率范围为fk-1～fk，对应的数字预失真系数向量为ck，k＝1,2,…,K，则K个频段对应K组系数向量c1,c2,…,cK；Suppose the frequency range occupied by the kth frequency band is f k-1 ~ f k , and the corresponding digital predistortion coefficient vector is c k , k=1,2,...,K, then K frequency bands correspond to K groups of coefficient vectors c 1 ,c 2 ,…,c K ;

S2.对K组数字预失真系数向量c1,c2,…,cK进行初始化的系数提取；S2. Initialize coefficient extraction for K sets of digital predistortion coefficient vectors c 1 , c 2 ,...,c K ;

S3.初始化系数提取完成后，对跳频基带信号进行数字预失真处理；S3. After the initialization coefficients are extracted, perform digital pre-distortion processing on the frequency hopping baseband signal;

S4.对跳频基带信号进行数字预失真处理后，送入功放中进行放大，检测功放输出信号的频谱，在数字预失真性能出现恶化，超出设定的指标需求时，进入步骤S5；S4. After performing digital pre-distortion processing on the frequency-hopping baseband signal, send it to the power amplifier for amplification, and detect the frequency spectrum of the power amplifier output signal. When the digital pre-distortion performance deteriorates and exceeds the set index requirements, enter step S5;

S5.对K组数字预失真系数向量c1,c2,…,cK进行更新。S5. Update K sets of digital predistortion coefficient vectors c 1 , c 2 , . . . , c K .

进一步地，所述步骤S1中划分频率的方式包括：Further, the way of dividing frequency in step S1 includes:

方式一、将工作频率范围f1～f2进行K等分的频段划分，即：Method 1: Divide the operating frequency range f 1 to f 2 into frequency bands divided into K equal parts, namely:

频段1的频率范围为

Figure BDA0003231925290000011
频段2的频率范围为
Figure BDA0003231925290000012
频段k的频率范围为
Figure BDA0003231925290000013
频段K的频率范围为
Figure BDA0003231925290000014
Figure BDA0003231925290000015
Band 1 has a frequency range of
Figure BDA0003231925290000011
Band 2 has a frequency range of
Figure BDA0003231925290000012
The frequency range of band k is
Figure BDA0003231925290000013
Band K has a frequency range of
Figure BDA0003231925290000014
Figure BDA0003231925290000015

方式二、根据功放的频率响应变化的程度大小进行划分：Method 2: Divide according to the degree of frequency response change of the power amplifier:

将工作频率范围f1～f2划分为K个连续的频段，并保证每个频段内，功放的频率响应中的幅度响应差异小于BdB。Divide the working frequency range f 1 to f 2 into K continuous frequency bands, and ensure that within each frequency band, the amplitude response difference in the frequency response of the power amplifier is less than BdB.

进一步地，所述步骤S2包括：Further, the step S2 includes:

S201.对第k组系数ck的初始化提取：S201. Extracting the initialization of the kth group of coefficients c k :

A1、根据第k组系数对应的频段范围fk-1～fk，构建一个带宽为fk-fk-1的宽带基带信号，将这个宽带基带信号记为记为x＝[x(1),x(2),...,x(N)]T；A1. Construct a broadband baseband signal with a bandwidth of f k -f k-1 according to the frequency band range f k-1 ~ f k corresponding to the k-th group of coefficients, and record this broadband baseband signal as x=[x(1 ),x(2),...,x(N)] T ;

A2、将带宽为fk-fk-1的宽带基带信号x上变频到载波频率为

Figure BDA0003231925290000021
的射频频段，上变频后的射频信号的频率范围为fk-1～fk；A2. Up-convert the broadband baseband signal x with a bandwidth of f k -f k-1 to a carrier frequency of
Figure BDA0003231925290000021
The radio frequency band, the frequency range of the up-converted radio frequency signal is f k-1 ~ f k ;

A3、将频率范围为fk-1～fk的射频信号通过功放，激发fk-1～fk内的非线性。A3. Pass the radio frequency signal in the frequency range of f k-1 to f k through the power amplifier to excite the nonlinearity in f k-1 to f k .

A4、将功放输出信号通过耦合器，再下变频到基带，再采集功放输出的基带信号yk＝[yk(1),yk(2),...,yk(N)]T；A4. Pass the output signal of the power amplifier through the coupler, then down-convert the frequency to the baseband, and then collect the baseband signal y k output by the power amplifier =[y k (1),y k (2),...,y k (N)] T ;

A5、根据基带功放输入数据x，以及采集的第k组基带功放输出数据yk，采用LS算法提取第k组DPD系数ck；其中，DPD系数即数字预失真系数，为了提高鲁棒性，对LS算法进行正则化：A5. According to the input data x of the baseband power amplifier, and the collected kth group of baseband power amplifier output data y k , use the LS algorithm to extract the kth group of DPD coefficients c k ; wherein, the DPD coefficient is the digital predistortion coefficient, in order to improve the robustness, Regularize the LS algorithm:

Figure BDA0003231925290000022
Figure BDA0003231925290000022

其中I为单位矩阵，γ为岭回归系数，Yk为采用yk中的数据，根据DPD模型基函数构建的数据矩阵：若DPD系数有L个，即ck＝[ck1,ck2,…,ckL]T,则Yk包含L个列向量，记为Yk＝[yk1,yk2,yk3,…,ykL]；每个列向量对应一个基函数：第l个列向量ykl，采用如下所示的DPD模型，Among them, I is the identity matrix, γ is the ridge regression coefficient, Y k is the data matrix constructed according to the basis function of the DPD model using the data in y k : if there are L coefficients in the DPD, that is c k =[c k1 , c k2 , …,c kL ] T , then Y k contains L column vectors, recorded as Y k =[y k1 ,y k2 ,y k3 ,…,y kL ]; each column vector corresponds to a basis function: the lth column vector y kl , using the DPD model shown below,

Figure BDA0003231925290000023
Figure BDA0003231925290000023

其中x(n)是模型输入，z(n)是输出，ul(x(n))代表基函数，典型的基函数为ul(x(n))＝x(n-m)|x(n-m)|p，其中p为非线性阶数，m为记忆深度，此时，ykl＝[ul(yk(1)),ul(yk(2)),…,ul(yk(N))]T；Where x(n) is the model input, z(n) is the output, u l (x(n)) represents the basis function, the typical basis function is u l (x(n))=x(nm)|x(nm )| p , where p is the nonlinear order, m is the memory depth, at this time, y kl ＝[u l (y k (1)),u l (y k (2)),…,u l (y k (N))] T ;

S202.对于每一个频段，重复步骤S201提取DPD系数，得到K组DPD系数c1,c2,…,cK。S202. For each frequency band, repeat step S201 to extract DPD coefficients to obtain K groups of DPD coefficients c 1 , c 2 , . . . , c K .

进一步地，所述步骤S3包括：Further, the step S3 includes:

S301.判断当前跳频频点所处的频段范围；若当前跳频频点落在fk-1～fk的频率范围内，则当前跳频频段处在第k个频段；S301. Determine the frequency band range where the current frequency hopping frequency point is located; if the current frequency hopping frequency point falls within the frequency range of f k-1 to f k , then the current frequency hopping frequency band is in the kth frequency band;

S302.采用第k组DPD系数ck＝[ck1,ck2,…,ckL]T对当前跳频频点对应的跳频基带信号进行数字预失真；将跳频基带信号记为v(n)，则用ck通过下式计算预失真后的信号：S302. Use the kth group of DPD coefficients c k =[c k1 , c k2 ,..., c kL ] T to perform digital pre-distortion on the frequency-hopping baseband signal corresponding to the current frequency-hopping frequency point; record the frequency-hopping baseband signal as v(n ), then use c k to calculate the predistorted signal by the following formula:

Figure BDA0003231925290000031
Figure BDA0003231925290000031

S303.将预失真后的信号z(n)上变频到当前跳频频点所在的位置，并发送给功放进行放大。S303. Up-convert the pre-distorted signal z(n) to the position of the current frequency hopping frequency point, and send it to the power amplifier for amplification.

进一步地，所述步骤S5中对K组DPD系数c1,c2,…,cK进行更新的方式包括如下两种：Further, in the step S5, the ways of updating K groups of DPD coefficients c 1 , c 2 , ..., c K include the following two methods:

第一种：第k组系数ck＝[ck1,ck2,…,ckL]T更新过程如下：The first type: the k-th group of coefficients c k =[c k1 ,c k2 ,…,c kL ] The update process of T is as follows:

B1、产生带宽为fk-fk-1的宽带基带信号x＝[x(1),x(2),...,x(N)]T；B1, the broadband baseband signal x=[x(1), x(2),...,x(N)] T of bandwidth f k -f k-1 is produced;

B2、将宽带基带信号x通过DPD得到预失真后的信号，即B2. Pass the broadband baseband signal x through DPD to obtain the predistorted signal, namely

Figure BDA0003231925290000032
Figure BDA0003231925290000032

其中ckl(l＝1,2,…,L)是还没有更新的DPD系数。将预失真信号z(n)记为z＝[z(1),z(2),...,z(N)]T；Where c kl (l=1, 2, . . . , L) are DPD coefficients that have not been updated yet. Denote the predistortion signal z(n) as z=[z(1),z(2),...,z(N)] T ;

B3、将z上变频到载波频率为

Figure BDA0003231925290000033
的射频频段；B3. Up-convert z to the carrier frequency as
Figure BDA0003231925290000033
the radio frequency band;

B4、将z上变频后的射频信号通过功放，将功放输出信号通过耦合器，再下变频到基带，再采集功放输出的基带信号yk＝[yk(1),yk(2),...,yk(N)]T；B4, pass the radio frequency signal after z up-conversion through the power amplifier, pass the power amplifier output signal through the coupler, then down-convert to the baseband, and then collect the baseband signal y k of the power amplifier output =[y k (1), y k (2), ...,y k (N)] T ;

B5、采用下式的岭回归更新第k组DPD系数ck B5. Use the ridge regression of the following formula to update the DPD coefficient c k of the kth group

Figure BDA0003231925290000034
Figure BDA0003231925290000034

其中Yk是数据矩阵，包含L个列向量，记为Yk＝[yk1,yk2,yk3,…,ykL]，第l个列向量ykl为ykl＝[ul(yk(1)),ul(yk(2)),…,ul(yk(N))]T，yk(1),yk(2),...,yk(N)是新采集的数据，对应z的功放输出数据；Among them, Y k is a data matrix, including L column vectors, recorded as Y k ＝[y k1 , y k2 , y k3 ,…,y kL ], the lth column vector y kl is y kl ＝[u l (y k (1)),u l (y k (2)),...,u l (y k (N))] T ，y k (1),y k (2),...,y k (N ) is newly collected data, corresponding to the power amplifier output data of z;

B6、重复以上步骤，对所有K组DPD系数c1,c2,…,cK进行更新；B6. Repeat the above steps to update all K groups of DPD coefficients c 1 , c 2 ,...,c K ;

第二种：根据跳频信号对DPD系数进行逐渐更新，步骤如下：The second method: gradually update the DPD coefficients according to the frequency hopping signal, the steps are as follows:

C1、判断当前跳频频点所处的频段范围，若当前跳频频段处在第k个频段，则第k组DPD系数ck＝[ck1,ck2,…,ckL]T进行更新；C1. Determine the frequency band range where the current frequency hopping frequency point is located. If the current frequency hopping frequency band is in the kth frequency band, then the kth group of DPD coefficients c k =[c k1 , c k2 ,..., c kL ] T is updated;

C2、首先对采用未更新的第k组DPD系数ck＝[ck1,ck2,…,ckL]T对跳频基带信号进行数字预失真，将跳频基带信号记为v(n)，则用ck通过下式计算预失真后的信号：C2. First, perform digital pre-distortion on the frequency-hopping baseband signal using the unupdated k-th group of DPD coefficients c k =[c k1 , c k2 ,...,c kL ] T , and record the frequency-hopping baseband signal as v(n) , then use c k to calculate the predistorted signal by the following formula:

Figure BDA0003231925290000035
Figure BDA0003231925290000035

其中ckl(l＝1,2,…,L)是还没有更新的DPD系数。将预失真信号z(n)记为z＝[z(1),z(2),...,z(N)]T；Where c kl (l=1, 2, . . . , L) are DPD coefficients that have not been updated yet. Denote the predistortion signal z(n) as z=[z(1),z(2),...,z(N)] T ;

C3、将预失真后的信号z(n)上变频到当前跳频频点所在的位置，并发送给功放，将功放输出信号通过耦合器，再下变频到基带，再采集功放输出的基带信号tk＝[yk(1),yk(2),...,yk(N)]T；C3. Up-convert the pre-distorted signal z(n) to the position where the current frequency hopping frequency is located, and send it to the power amplifier, pass the power amplifier output signal through the coupler, then down-convert to the baseband, and then collect the baseband signal t output by the power amplifier k = [y k (1), y k (2), . . . , y k (N)] T ;

C4、采用下式的对第k组系数ck进行更新：C4, adopt the following formula to update the coefficient c k of the kth group:

Figure BDA0003231925290000041
Figure BDA0003231925290000041

其中

Figure BDA0003231925290000042
是更新后第k组系数，μ表示更新步长，μ的取值为0≤μ≤1；Yk是数据矩阵，包含L个列向量，记为Yk＝[yk1,yk2,yk3,…,ykL]，第l个列向量ykl为ykl＝[ul(yk(1)),ul(yk(2)),…,ul(yk(N))]T，其中yk(1),yk(2),...,yk(N)是新采集的功放输出基带数据。in
Figure BDA0003231925290000042
is the kth group of coefficients after update, μ represents the update step size, and the value of μ is 0≤μ≤1; Y k is a data matrix, including L column vectors, recorded as Y k ＝[y k1 ,y k2 ,y k3 ,…,y kL ], the l-th column vector y kl is y kl =[u l (y k (1)),u l (y k (2)),…,u l (y k (N) )] T , where y k (1), y k (2),...,y k (N) are newly collected power amplifier output baseband data.

C5、通过以上步骤，当跳频频点的位置在所有的K个频段都存在过后，即能够对所有的K组DPD系数c1,c2，…，cK进行更新。C5. Through the above steps, when the positions of frequency hopping frequency points exist in all K frequency bands, all K groups of DPD coefficients c 1 , c 2 , . . . , c K can be updated.

一种针对跳频通信的数字预失真校正装置，包括：A digital predistortion correction device for frequency hopping communication, comprising:

频段划分模块，用于根据跳频系统的工作频率范围，将工作频率范围划分为K个不同的频段，每个频段都采用一组数字预失真系数：The frequency band division module is used to divide the operating frequency range into K different frequency bands according to the operating frequency range of the frequency hopping system, and each frequency band adopts a set of digital predistortion coefficients:

初始化系数提取模块，用于对对K组预失真系数向量进行初始化的系数提取；The initialization coefficient extraction module is used to extract coefficients for initializing K groups of predistortion coefficient vectors;

数字预失真处理模块，用于在初始化系数提取完成后，对跳频基带信号进行数字预失真处理；The digital pre-distortion processing module is used for performing digital pre-distortion processing on the frequency-hopping baseband signal after the initialization coefficient extraction is completed;

性能检测模块，用于在对跳频基带信号进行数字预失真处理后，对包含了DPD的跳频系统进行性能检测，检测功放输出信号的频谱，在DPD性能出现恶化超出指标需求时，通知系数更新模块；The performance detection module is used to perform performance detection on the frequency hopping system including DPD after performing digital pre-distortion processing on the frequency hopping baseband signal, detect the frequency spectrum of the power amplifier output signal, and notify the coefficient when the DPD performance deteriorates beyond the index requirements update module;

系数更新模块，用于对K组DPD系数c1，c2，…，cK进行更新。A coefficient updating module, configured to update K groups of DPD coefficients c 1 , c 2 , . . . , c K .

本发明的有益效果是：本发明通过设计宽带信号激发功放在一个宽带频率范围内的非线性，并用一组DPD系数来矫正该宽带频率范围内的非线性。这样，只要跳频频点处在该宽带频率范围内，都可以采用提取的那一组系数进行DPD矫正。对于跳频频点很多的跳频系统，本发明只需要提取K组DPD系数。其中K可以根据复杂度进行调整。K可以设置的比较小以保证较低的复杂度。本发明采用了岭回归方法计算DPD系数，可以提高DPD系数提取的鲁棒性。所提取的DPD系数可以更好的适应对应频率范围内的不同跳频频点。本发明包含了DPD系数的初始化计算过程以及DPD系数的更新过程，有利于持续优化预失真系数，提高预失真处理的准确性。The beneficial effects of the present invention are: the present invention excites the nonlinearity in a wideband frequency range by designing a wideband signal, and uses a set of DPD coefficients to correct the nonlinearity in the wideband frequency range. In this way, as long as the frequency hopping frequency is within the broadband frequency range, the extracted set of coefficients can be used for DPD correction. For a frequency hopping system with many frequency hopping frequency points, the present invention only needs to extract K groups of DPD coefficients. where K can be adjusted according to the complexity. K can be set relatively small to ensure low complexity. The invention adopts the ridge regression method to calculate the DPD coefficient, which can improve the robustness of the DPD coefficient extraction. The extracted DPD coefficients can better adapt to different frequency hopping frequency points within the corresponding frequency range. The invention includes the initial calculation process of DPD coefficients and the update process of DPD coefficients, which is beneficial to continuously optimize the pre-distortion coefficients and improve the accuracy of pre-distortion processing.

附图说明Description of drawings

图1为本发明的方法流程图；Fig. 1 is method flowchart of the present invention;

图2为实施例中的频段划分示意图；FIG. 2 is a schematic diagram of frequency band division in an embodiment;

图3为本发明的装置原理示意图。Fig. 3 is a schematic diagram of the principle of the device of the present invention.

具体实施方式Detailed ways

下面结合附图进一步详细描述本发明的技术方案，但本发明的保护范围不局限于以下所述。The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following description.

如图1所示，一种针对跳频通信的数字预失真校正方法，包括以下步骤：As shown in Figure 1, a digital predistortion correction method for frequency hopping communication includes the following steps:

S1.根据跳频系统的工作频率范围f1～f2，将工作频率范围划分为K个不同的频段，每个频段都采用一组数字预失真系数：只要是落在该频段内的频点，都采用该频段的对应的DPD系数进行矫正，频段划分如下图2所示S1. According to the working frequency range f 1 ~ f 2 of the frequency hopping system, the working frequency range is divided into K different frequency bands, and each frequency band adopts a set of digital pre-distortion coefficients: as long as the frequency points fall within the frequency band , are corrected using the corresponding DPD coefficients of the frequency band, and the frequency band division is shown in Figure 2 below

设第k个频段占据的频率范围为fk-1～fk，对应的数字预失真系数向量为ck，k＝1,2,…,K，则K个频段对应K组系数向量c1,c2,…,cK；Suppose the frequency range occupied by the kth frequency band is f k-1 ~ f k , and the corresponding digital predistortion coefficient vector is c k , k=1,2,...,K, then K frequency bands correspond to K groups of coefficient vectors c 1 ,c 2 ,…,c K ;

划分频率的方式包括：The ways of dividing frequency include:

方式一、将工作频率范围f1～f2进行K等分的频段划分，即：Method 1: Divide the operating frequency range f 1 to f 2 into frequency bands divided into K equal parts, namely:

频段1的频率范围为

Figure BDA0003231925290000051
频段2的频率范围为
Figure BDA0003231925290000052
频段k的频率范围为
Figure BDA0003231925290000053
频段K的频率范围为
Figure BDA0003231925290000054
Figure BDA0003231925290000055
Band 1 has a frequency range of
Figure BDA0003231925290000051
Band 2 has a frequency range of
Figure BDA0003231925290000052
The frequency range of band k is
Figure BDA0003231925290000053
Band K has a frequency range of
Figure BDA0003231925290000054
Figure BDA0003231925290000055

例如，架设跳频系统的工作频率范围为f1＝1900MHz到f2＝2100MHz，即所有的跳频频点都在1900MHz到2100MHz内。此时，可以将跳频频段划分为K＝4个等分的频段，分别是1900MHz～1950MHz，1950MHz～2000MHz，2000MHz～2050MHz，2050MHz～2010MHz。For example, the working frequency range of setting up the frequency hopping system is f 1 =1900MHz to f 2 =2100MHz, that is, all frequency hopping frequency points are within 1900MHz to 2100MHz. At this time, the frequency hopping frequency band can be divided into K=4 equally divided frequency bands, which are 1900MHz-1950MHz, 1950MHz-2000MHz, 2000MHz-2050MHz, and 2050MHz-2010MHz.

方式二、根据功放的频率响应变化的程度大小进行划分：Method 2: Divide according to the degree of frequency response change of the power amplifier:

将工作频率范围f1～f2划分为K个连续的频段，并保证每个频段内，功放的频率响应中的幅度响应差异小于BdB。其中BdB可以根据实际需要进行调整，典型的BdB可以选择为0.5dB和1dB。Divide the working frequency range f 1 to f 2 into K continuous frequency bands, and ensure that within each frequency band, the amplitude response difference in the frequency response of the power amplifier is less than BdB. Among them, BdB can be adjusted according to actual needs, and typical BdB can be selected as 0.5dB and 1dB.

S2.对K组数字预失真系数向量c1,c2,…,cK进行初始化的系数提取；S2. Initialize coefficient extraction for K sets of digital predistortion coefficient vectors c 1 , c 2 ,...,c K ;

所述步骤S2包括：Described step S2 comprises:

S201.对第k组系数ck的初始化提取：S201. Extracting the initialization of the kth group of coefficients c k :

A1、根据第k组系数对应的频段范围fk-1～fk，构建一个带宽为fk-fk-1的宽带基带信号，将这个宽带基带信号记为记为x＝[x(1),x(2),...,x(N)]T；A1. Construct a broadband baseband signal with a bandwidth of f k -f k-1 according to the frequency band range f k-1 ~ f k corresponding to the k-th group of coefficients, and record this broadband baseband signal as x=[x(1 ),x(2),...,x(N)] T ;

例如，当第k＝1个频段范围为1900MHz～1950MHz时，此时构建一个带宽为50MHz的宽带信号。For example, when the k=1th frequency band ranges from 1900 MHz to 1950 MHz, a broadband signal with a bandwidth of 50 MHz is constructed at this time.

A2、将带宽为fk-fk-1的宽带基带信号x上变频到载波频率为

Figure BDA0003231925290000061
的射频频段，上变频后的射频信号的频率范围为fk-1～fk；A2. Up-convert the broadband baseband signal x with a bandwidth of f k -f k-1 to a carrier frequency of
Figure BDA0003231925290000061
The radio frequency band, the frequency range of the up-converted radio frequency signal is f k-1 ~ f k ;

A3、将频率范围为fk-1～fk的射频信号通过功放，激发fk-1～fk内的非线性。A3. Pass the radio frequency signal in the frequency range of f k-1 to f k through the power amplifier to excite the nonlinearity in f k-1 to f k .

A4、将功放输出信号通过耦合器，再下变频到基带，再采集功放输出的基带信号yk＝[yk(1),yk(2),...,yk(N)]T；A4. Pass the output signal of the power amplifier through the coupler, then down-convert the frequency to the baseband, and then collect the baseband signal y k output by the power amplifier =[y k (1),y k (2),...,y k (N)] T ;

A5、根据基带功放输入数据x，以及采集的第k组基带功放输出数据yk，采用LS算法提取第k组DPD系数ck；其中，DPD系数即数字预失真系数，为了提高鲁棒性，对LS算法进行正则化：A5. According to the input data x of the baseband power amplifier, and the collected kth group of baseband power amplifier output data y k , use the LS algorithm to extract the kth group of DPD coefficients c k ; wherein, the DPD coefficient is the digital predistortion coefficient, in order to improve the robustness, Regularize the LS algorithm:

Figure BDA0003231925290000062
Figure BDA0003231925290000062

其中I为单位矩阵，γ为岭回归系数，(γ也可以被称为正则化因子)。γ的典型值可以从0.1,0.01,0.001,0.0001,0.00001中选择；Yk为采用yk中的数据，根据DPD模型基函数构建的数据矩阵：若DPD系数有L个，即ck＝[ck1,ck2,…,ckL]T,则Yk包含L个列向量，记为Yk＝[yk1,yk2,yk3,…,ykL]；每个列向量对应一个基函数：第l个列向量ykl，采用如下所示的DPD模型，Where I is the identity matrix, and γ is the ridge regression coefficient, (γ can also be called a regularization factor). The typical value of γ can be selected from 0.1, 0.01, 0.001, 0.0001, 0.00001; Y k is the data matrix constructed according to the basis function of the DPD model using the data in y k : if there are L DPD coefficients, that is c k = [ c k1 ,c k2 ,…,c kL ] T , then Y k contains L column vectors, recorded as Y k =[y k1 ,y k2 ,y k3 ,…,y kL ]; each column vector corresponds to a basis Function: The l-th column vector y kl adopts the DPD model shown below,

Figure BDA0003231925290000063
Figure BDA0003231925290000063

其中x(n)是模型输入，z(n)是输出，ul(x(n))代表基函数，典型的基函数为ul(x(n))＝x(n-m)|x(n-m)|p，其中p为非线性阶数，m为记忆深度，此时，ykl＝[ul(yk(1)),ul(yk(2)),…,ul(yk(N))]T；Where x(n) is the model input, z(n) is the output, u l (x(n)) represents the basis function, the typical basis function is u l (x(n))=x(nm)|x(nm )| p , where p is the nonlinear order, m is the memory depth, at this time, y kl ＝[u l (y k (1)),u l (y k (2)),…,u l (y k (N))] T ;

S202.对于每一个频段，重复步骤S201提取DPD系数，得到K组DPD系数c1,c2,…,cK。S202. For each frequency band, repeat step S201 to extract DPD coefficients to obtain K groups of DPD coefficients c 1 , c 2 , . . . , c K .

S3.初始化系数提取完成后，对跳频基带信号进行数字预失真处理；S3. After the initialization coefficients are extracted, perform digital pre-distortion processing on the frequency hopping baseband signal;

S4.对跳频基带信号进行数字预失真处理后，送入功放中进行放大，检测功放输出信号的频谱，在数字预失真性能出现恶化，超出设定的指标需求时，进入步骤S5；S4. After performing digital pre-distortion processing on the frequency-hopping baseband signal, send it to the power amplifier for amplification, and detect the frequency spectrum of the power amplifier output signal. When the digital pre-distortion performance deteriorates and exceeds the set index requirements, enter step S5;

若数字预失真性能未超出设定的指标需求，则无需更新系数，继续利用当前的系数向量进行预失真处理。If the digital pre-distortion performance does not exceed the set index requirement, there is no need to update the coefficients, and the current coefficient vector continues to be used for pre-distortion processing.

在本申请的实施例中，指标一般采用功放输出信号的频谱的ACLR(相邻信道泄漏比)，设定的指标需求，一般是指功放输出信号的频谱的ACLR(相邻信道泄漏比)指标需要小于-45dBc。此时检测功放输出信号频谱，如果发现ACLR指标如果大于-45dBc，就认为是性能恶化，超出了指标需求。In the embodiment of the present application, the index generally adopts the ACLR (adjacent channel leakage ratio) of the frequency spectrum of the power amplifier output signal, and the set index requirements generally refer to the ACLR (adjacent channel leakage ratio) index of the frequency spectrum of the power amplifier output signal Less than -45dBc is required. At this time, check the output signal spectrum of the power amplifier. If the ACLR index is found to be greater than -45dBc, it is considered that the performance has deteriorated and exceeded the index requirements.

S5.对K组数字预失真系数向量c1,c2,…,cK进行更新。S5. Update K sets of digital predistortion coefficient vectors c 1 , c 2 , . . . , c K .

进一步地，所述步骤S3包括：Further, the step S3 includes:

S301.判断当前跳频频点所处的频段范围；若当前跳频频点落在fk-1～fk的频率范围内，则当前跳频频段处在第k个频段；S301. Determine the frequency band range where the current frequency hopping frequency point is located; if the current frequency hopping frequency point falls within the frequency range of f k-1 to f k , then the current frequency hopping frequency band is in the kth frequency band;

S302.采用第k组DPD系数ck＝[ck1,ck2,…,ckL]T对当前跳频频点对应的跳频基带信号进行数字预失真；将跳频基带信号记为v(n)，则用ck通过下式计算预失真后的信号：S302. Use the kth group of DPD coefficients c k =[c k1 , c k2 ,..., c kL ] T to perform digital pre-distortion on the frequency-hopping baseband signal corresponding to the current frequency-hopping frequency point; record the frequency-hopping baseband signal as v(n ), then use c k to calculate the predistorted signal by the following formula:

Figure BDA0003231925290000071
Figure BDA0003231925290000071

S303.将预失真后的信号z(n)上变频到当前跳频频点所在的位置，并发送给功放进行放大。S303. Up-convert the pre-distorted signal z(n) to the position of the current frequency hopping frequency point, and send it to the power amplifier for amplification.

进一步地，所述步骤S5中对K组DPD系数c1,c2,…,cK进行更新的方式包括如下两种：Further, in the step S5, the ways of updating K groups of DPD coefficients c 1 , c 2 , ..., c K include the following two methods:

第一种：第k组系数ck＝[ck1,ck2,…,ckL]T更新过程如下：The first type: the k-th group of coefficients c k =[c k1 ,c k2 ,…,c kL ] The update process of T is as follows:

B1、产生带宽为fk-fk-1的宽带基带信号x＝[x(1),x(2),...,x(N)]T；B1, the broadband baseband signal x=[x(1), x(2),...,x(N)] T of bandwidth f k -f k-1 is produced;

B2、将宽带基带信号x通过DPD得到预失真后的信号，即B2. Pass the broadband baseband signal x through DPD to obtain the predistorted signal, namely

Figure BDA0003231925290000072
Figure BDA0003231925290000072

其中ckl(l＝1,2,…,L)是还没有更新的DPD系数。将预失真信号z(n)记为z＝[z(1),z(2),...,z(N)]T；Where c kl (l=1, 2, . . . , L) are DPD coefficients that have not been updated yet. Denote the predistortion signal z(n) as z=[z(1),z(2),...,z(N)] T ;

B3、将z上变频到载波频率为

Figure BDA0003231925290000073
的射频频段；B3. Up-convert z to the carrier frequency as
Figure BDA0003231925290000073
the radio frequency band;

B4、将z上变频后的射频信号通过功放，将功放输出信号通过耦合器，再下变频到基带，再采集功放输出的基带信号yk＝[yk(1),yk(2),...,yk(N)]T；B4, pass the radio frequency signal after z up-conversion through the power amplifier, pass the power amplifier output signal through the coupler, then down-convert to the baseband, and then collect the baseband signal y k of the power amplifier output =[y k (1), y k (2), ...,y k (N)] T ;

B5、采用下式的岭回归更新第k组DPD系数ck B5. Use the ridge regression of the following formula to update the DPD coefficient c k of the kth group

Figure BDA0003231925290000074
Figure BDA0003231925290000074

其中Yk是数据矩阵，包含L个列向量，记为Yk＝[yk1,yk2,yk3,…,ykL]，第l个列向量ykl为ykl＝[ul(yk(1)),ul(yk(2)),…,ul(yk(N))]T，yk(1),yk(2),...,yk(N)是新采集的数据，对应z的功放输出数据；Among them, Y k is a data matrix, including L column vectors, recorded as Y k ＝[y k1 , y k2 , y k3 ,…,y kL ], the lth column vector y kl is y kl ＝[u l (y k (1)),u l (y k (2)),...,u l (y k (N))] T ，y k (1),y k (2),...,y k (N ) is newly collected data, corresponding to the power amplifier output data of z;

B6、重复以上步骤，对所有K组DPD系数c1,c2,…,cK进行更新；B6. Repeat the above steps to update all K groups of DPD coefficients c 1 , c 2 ,...,c K ;

第二种：根据跳频信号对DPD系数进行逐渐更新，步骤如下：The second method: gradually update the DPD coefficients according to the frequency hopping signal, the steps are as follows:

C1、判断当前跳频频点所处的频段范围，若当前跳频频段处在第k个频段，则第k组DPD系数ck＝[ck1,ck2,…,ckL]T进行更新；C1. Determine the frequency band range where the current frequency hopping frequency point is located. If the current frequency hopping frequency band is in the kth frequency band, then the kth group of DPD coefficients c k =[c k1 , c k2 ,..., c kL ] T is updated;

C2、首先对采用未更新的第k组DPD系数ck＝[ck1,ck2,…,ckL]T对跳频基带信号进行数字预失真，将跳频基带信号记为v(n)，则用ck通过下式计算预失真后的信号：C2. First, perform digital pre-distortion on the frequency-hopping baseband signal using the unupdated k-th group of DPD coefficients c k =[c k1 , c k2 ,...,c kL ] T , and record the frequency-hopping baseband signal as v(n) , then use c k to calculate the predistorted signal by the following formula:

Figure BDA0003231925290000081
Figure BDA0003231925290000081

其中ckl(l＝1,2,…,L)是还没有更新的DPD系数。将预失真信号z(n)记为z＝[z(1),z(2),...,z(N)]T；Where c kl (l=1, 2, . . . , L) are DPD coefficients that have not been updated yet. Denote the predistortion signal z(n) as z=[z(1),z(2),...,z(N)] T ;

C3、将预失真后的信号z(n)上变频到当前跳频频点所在的位置，并发送给功放，将功放输出信号通过耦合器，再下变频到基带，再采集功放输出的基带信号yk＝[yk(1),yk(2),...,yk(N)]T；C3. Up-convert the pre-distorted signal z(n) to the position where the current frequency hopping frequency is located, and send it to the power amplifier, pass the power amplifier output signal through the coupler, and then down-convert the frequency to the baseband, and then collect the baseband signal y output by the power amplifier k = [y k (1), y k (2), . . . , y k (N)] T ;

C4、采用下式的对第k组系数ck进行更新：C4, adopt the following formula to update the coefficient c k of the kth group:

Figure BDA0003231925290000082
Figure BDA0003231925290000082

其中

Figure BDA0003231925290000083
是更新后第k组系数，μ表示更新步长，μ的取值为0≤μ≤1；Yk是数据矩阵，包含L个列向量，记为Yk＝[yk1,yk2,yk3,…,ykL]，第l个列向量ykl为ykl＝[ul(yk(1))，ul(yk(2))，…，ul(yk(N))]T，其中yk(1)，yk(2)，...，yk(N)是新采集的功放输出基带数据。in
Figure BDA0003231925290000083
is the kth group of coefficients after update, μ represents the update step size, and the value of μ is 0≤μ≤1; Y k is a data matrix, including L column vectors, recorded as Y k ＝[y k1 ,y k2 ,y k3 ,...,y kL ], the l-th column vector y kl is y kl =[u l (y k (1)), u l (y k (2)),..., u l (y k (N) )] T , where y k (1), y k (2), ..., y k (N) are newly collected power amplifier output baseband data.

C5、通过以上步骤，当跳频频点的位置在所有的K个频段都存在过后，即能够对所有的K组DPD系数c1,c2，…，cK进行更新。C5. Through the above steps, when the positions of frequency hopping frequency points exist in all K frequency bands, all K groups of DPD coefficients c 1 , c 2 , . . . , c K can be updated.

如图3所示，一种针对跳频通信的数字预失真校正装置，包括：As shown in Figure 3, a digital predistortion correction device for frequency hopping communication, including:

频段划分模块，用于根据跳频系统的工作频率范围，将工作频率范围划分为K个不同的频段，每个频段都采用一组数字预失真系数：The frequency band division module is used to divide the operating frequency range into K different frequency bands according to the operating frequency range of the frequency hopping system, and each frequency band adopts a set of digital predistortion coefficients:

初始化系数提取模块，用于对对K组预失真系数向量进行初始化的系数提取；The initialization coefficient extraction module is used to extract coefficients for initializing K groups of predistortion coefficient vectors;

数字预失真处理模块，用于在初始化系数提取完成后，对跳频基带信号进行数字预失真处理；The digital pre-distortion processing module is used for performing digital pre-distortion processing on the frequency-hopping baseband signal after the initialization coefficient extraction is completed;

性能检测模块，用于在对跳频基带信号进行数字预失真处理后，对包含了DPD的跳频系统进行性能检测，检测功放输出信号的频谱，在DPD性能出现恶化超出指标需求时，通知系数更新模块；The performance detection module is used to perform performance detection on the frequency hopping system including DPD after performing digital pre-distortion processing on the frequency hopping baseband signal, detect the frequency spectrum of the power amplifier output signal, and notify the coefficient when the DPD performance deteriorates beyond the index requirements update module;

系数更新模块，用于对K组DPD系数c1，c2，…，cK进行更新。A coefficient updating module, configured to update K groups of DPD coefficients c 1 , c 2 , . . . , c K .

以上实施例仅用以说明本发明的技术方案，而非对其限制；尽管参照前述实施例对本发明进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本发明各实施例技术方案的精神和范围。The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be described in the foregoing embodiments Modifications are made to the recorded technical solutions, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (5)

1. A digital predistortion correction method for frequency hopping communications, characterized by: the method comprises the following steps:
s1, according to the working frequency range f of a frequency hopping system 1 ～f 2 The working frequency range is divided into K different frequency bands, and each frequency band adopts a group of digital predistortion coefficients:
let the frequency range occupied by the kth frequency band be f k-1 ～f k The corresponding digital predistortion coefficient vector is c k K =1, 2.. K, then K frequency bands correspond to K sets of coefficient vectors c 1 ，c 2 ，...，c K ；
S2, for K groups of digital predistortion coefficient vectors c 1 ，c 2 ，...，c K Performing initialized coefficient extraction;
the step S2 includes:
s201, for k group of coefficients c k The initialization extraction:
a1, frequency band range f corresponding to the k group of coefficients k-1 ～f k Constructing a bandwidth of f k -f k-1 Is denoted as x = [ x (1), x (2),. ], x (N)] T ；
A2, setting the bandwidth as f k -f k-1 Up-converting the broadband baseband signal x to a carrier frequency of
Figure FDA0003800065710000011
The frequency range of the up-converted RF signal is f k-1 ～f k ；
A3, setting the frequency range as f k-1 ～f k The radio frequency signal of (2) is amplified and excited k-1 ～f k Internal non-linearity;
a4, the output signal of the power amplifier is converted to a baseband through the coupler and then the baseband signal y output by the power amplifier is collected k ＝[y k (1)，y k (2)，...，y k (N)] T ；
A5, according to the baseband power amplifier input data x and the collected kth group of baseband power amplifier output data y k Extracting the k-th group of DPD coefficients c by adopting LS algorithm k (ii) a The DPD coefficient is a digital predistortion coefficient, and in order to improve robustness, the LS algorithm is regularized:
Figure FDA0003800065710000012
wherein I is a unit matrix, gamma is a ridge regression coefficient, and Y is k To adopt y k The data in (1) is a data matrix constructed according to the basis functions of the DPD model: if there are L DPD coefficients, i.e. c k ＝[c k1 ，c k2 ，...，c kL ] T Then Y is k Contains L column vectors, denoted as Y k ＝[y k1 ，y k2 ，y k3 ，...，y kL ](ii) a Each column vector corresponds to a basis function: the l column vector y kl Using the DPD model as shown below,
Figure FDA0003800065710000013
where x (n) is the model input, z (n) is the output, u l (x (n)) represents a basis function, typically u l (x(n))＝x(n-m)|x(n-m)| p Where p is the nonlinear order and m is the memory depth, then y kl ＝[u l (y k (1))，u l (y k (2))，...，u l (y k (N))] T ；
S202, for each frequency band, repeating the step S201 to extract the DPD coefficients to obtain K groups of DPD coefficients c 1 ，c 2 ，...，c K ；
S3, after the extraction of the initialization coefficient is completed, carrying out digital pre-distortion processing on the frequency hopping baseband signal;
s4, after carrying out digital predistortion processing on the frequency hopping baseband signal, sending the frequency hopping baseband signal into a power amplifier for amplification, detecting the frequency spectrum of an output signal of the power amplifier, and entering a step S5 when the digital predistortion performance is deteriorated and exceeds a set index requirement;
s5, for K groups of digital predistortion coefficient vectors c 1 ，c 2 ，...，c K And (6) updating.
2. A digital predistortion correction method for frequency hopping communications according to claim 1, characterized in that: the frequency division mode in step S1 includes:
mode one, the working frequency range f 1 ～f 2 Performing frequency division of K equal parts, namely:
frequency range of frequency band 1 is
Figure FDA0003800065710000021
Frequency band 2 has a frequency range of
Figure FDA0003800065710000022
Frequency range of frequency band k of
Figure FDA0003800065710000023
Frequency range of frequency band K
Figure FDA0003800065710000024
Figure FDA0003800065710000025
And a second mode, dividing according to the degree of frequency response change of the power amplifier:
will operate in a frequency range f 1 ～f 2 And dividing the frequency bands into K continuous frequency bands, and ensuring that the amplitude response difference in the frequency response of the power amplifier in each frequency band is less than BdB.
3. A digital predistortion correction method for frequency hopping communications according to claim 1, characterized in that: the step S3 includes:
s301, judging the frequency range of the current frequency hopping frequency point; if the current frequency hopping frequency point falls on f k-1 ～f k Within the frequency range of (2), the current frequency hopping band is in the kth frequency band;
s302, adopting a k group of DPD coefficients c k ＝[c k1 ，c k2 ，...，c kL ] T Carrying out digital predistortion on a frequency hopping baseband signal corresponding to a current frequency hopping point; let the frequency hopping baseband signal be v (n), then use c k The pre-distorted signal is calculated by:
Figure FDA0003800065710000026
and S303, up-converting the pre-distorted signal z (n) to the position of the current frequency hopping frequency point, and sending the signal to a power amplifier for amplification.
4. A digital predistortion correction method for frequency hopping communications according to claim 1, characterized in that: for K groups of DPD coefficients c in the step S5 1 ，c 2 ，...，c K The updating method comprises the following two methods:
the first method comprises the following steps: k group coefficient c k ＝[c k1 ，c k2 ，...，c kL ] T The updating process is as follows:
b1, generating bandwidth of f k -f k-1 Is used to generate a wideband baseband signal of (1) = [ x (1), x (2) ], x (N)] T ；
B2, obtaining a signal after predistortion by the wide-band baseband signal x through DPD, namely
Figure FDA0003800065710000027
Wherein c is kl (L =1, 2.. Gtoreq.l) is a DPD coefficient that has not been updated, and the predistortion signal z (N) is denoted as z = [ z (1), z (2),. Gtoreq.z (N)] T ；
B3, up-converting z toA carrier frequency of
Figure FDA0003800065710000031
The radio frequency band of (c);
b4, the radio-frequency signal after the z up-conversion is subjected to power amplification, the output signal of the power amplification is subjected to down-conversion to a baseband through a coupler, and then the baseband signal y output by the power amplification is collected k ＝[y k (1)，y k (2)，...，y k (N)] T ；
B5, updating the kth group of DPD coefficients c by ridge regression of the following formula k
Figure FDA0003800065710000032
Wherein Y is k Is a data matrix containing L column vectors, denoted as Y k ＝[y k1 ，y k2 ，y k3 ，...，y kL ]The l-th column vector y kl Is y kl ＝[u l (y k (1))，u l (y k (2))，...，u l (y k (N))] T ，y k (1)，y k (2)，...，y k (N) newly acquired data corresponding to the z power amplifier output data;
b6, repeating the steps, and carrying out treatment on all K groups of DPD coefficients c 1 ，c 2 ，...，c K Updating is carried out;
and the second method comprises the following steps: gradually updating the DPD coefficient according to the frequency hopping signal, comprising the following steps:
c1, judging the frequency range of the current frequency hopping frequency point, if the current frequency hopping frequency band is in the kth frequency band, determining the kth group of DPD coefficients C k ＝[c k1 ，c k2 ，...，c kL ] T Updating is carried out;
c2, firstly adopting the k-th group of DPD coefficients C which are not updated k ＝[c k1 ，c k2 ，...，c kL ] T Digitally pre-distorting the frequency hopping baseband signal, and marking the frequency hopping baseband signal as v (n), using c k Calculating the pre-distorted signal by：
Figure FDA0003800065710000033
Wherein c is kl (L =1, 2.. So, L) is a DPD coefficient which has not been updated, and the predistortion signal z (N) is denoted as z = [ z (1), z (2),. So, z (N)] T ；
C3, up-converting the pre-distorted signal z (n) to the position of the current frequency hopping frequency point, sending the signal to a power amplifier, passing the output signal of the power amplifier through a coupler, down-converting the signal to a baseband, and collecting the baseband signal y output by the power amplifier k ＝[y k (1)，y k (2)，...，y k (N)] T ；
C4, a coefficient C of the kth group using the formula k And (3) updating:
Figure FDA0003800065710000034
wherein
Figure FDA0003800065710000035
Is the k-th group coefficient after updating, mu represents the updating step length, and the value of mu is more than or equal to 0 and less than or equal to 1; y is k Is a data matrix containing L column vectors, denoted as Y k ＝[y k1 ，y k2 ，y k3 ，...，y kL ]The ith column vector y kl Is y kl ＝[u l (y k (1))，u l (y k (2))，...，u l (y k (N))] T Wherein y is k (1)，y k (2)，...，y k (N) newly acquired power amplifier output baseband data;
c5, through the steps, after the positions of the frequency hopping points exist in all K frequency bands, all K groups of DPD coefficients C can be processed 1 ，c 2 ，...，c K And (6) updating.
5. A digital predistortion correction device for frequency hopping communication, based on the method of any one of claims 1 to 4, characterized in that: the method comprises the following steps:
the frequency band division module is used for dividing the working frequency range into K different frequency bands according to the working frequency range of the frequency hopping system, and each frequency band adopts a group of digital predistortion coefficients:
the initialization coefficient extraction module is used for performing initialized coefficient extraction on the K groups of predistortion coefficient vectors;
the digital pre-distortion processing module is used for performing digital pre-distortion processing on the frequency hopping baseband signal after the extraction of the initialization coefficient is finished;
the performance detection module is used for performing performance detection on a frequency hopping system containing the DPD after performing digital pre-distortion processing on the frequency hopping baseband signal, detecting the frequency spectrum of the output signal of the power amplifier, and informing the coefficient updating module when the DPD performance is deteriorated and exceeds the index requirement;
a coefficient updating module for updating K groups of DPD coefficients c 1 ,c 2 ,…,c K And (4) updating.
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