CN115378371A - Signal processing method for band-limited predistortion system and band-limited predistortion system - Google Patents

Signal processing method for band-limited predistortion system and band-limited predistortion system Download PDF

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CN115378371A
CN115378371A CN202110548367.7A CN202110548367A CN115378371A CN 115378371 A CN115378371 A CN 115378371A CN 202110548367 A CN202110548367 A CN 202110548367A CN 115378371 A CN115378371 A CN 115378371A
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filter
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于翠屏
唐珂
刘元安
黎淑兰
苏明
王为民
吴永乐
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Beijing University of Posts and Telecommunications
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    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
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    • H03F1/32—Modifications of amplifiers to reduce non-linear distortion

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Abstract

The embodiment of the invention provides a signal processing method for a band-limited predistortion system and the band-limited predistortion system, wherein the method comprises the following steps: determining model parameters of a power amplifier model to be established based on historical original signals input to a digital-to-analog conversion and up-conversion module, historical feedback signals output by an analog-to-digital conversion and down-conversion module, baseband response of a filter, total order of the filter and a preset band-limited pre-distortion system model; establishing a power amplifier model based on the model parameters; and determining a predistortion model based on the power amplifier model and the historical original signal, so that the signal obtained after the historical original signal passes through the predistorter and the power amplifier is linear with the original signal. The influence of the filter on the model memory depth is considered when the power amplifier model is established, so that the obtained power amplifier model is more accurate, and the linearization effect is better when the power amplifier model and the predistortion model are used for carrying out predistortion and amplification treatment on signals.

Description

Signal processing method for band-limited predistortion system and band-limited predistortion system
Technical Field
The present invention relates to the field of communications technologies, and in particular, to a signal processing method for a band-limited predistortion system and a band-limited predistortion system.
Background
Currently, in order to correct the nonlinear distortion of a signal generated by a power amplifier, the signal needs to be linearized. Among linearization techniques, the predistortion technique is widely used due to its low complexity, high stability, wide bandwidth, good linearization performance, and so on. The predistortion technology is that a predistorter with the characteristic opposite to that of a power amplifier is added at the front end of the power amplifier, a signal is subjected to predistortion treatment through the predistorter, the signal subjected to predistortion treatment is subjected to power amplifier, and the characteristic of the predistorter and the characteristic of the power amplifier are mutually compensated, so that the output signal of the power amplifier and the original input signal are in a linear relation, and the signal is subjected to linearization treatment.
To solve the cost problem of the feedback loop ADC (Analog-to-Digital Converter), a band-limited predistortion technique is proposed, which limits the sampling rate of the ADC by introducing a filter in the feedback loop. In the band-limited predistortion technique, the effect of achieving linearization of the signal generally depends on the accuracy of modeling the power amplifier model. When the modeling accuracy of the power amplifier model is higher, the linearization effect on the signal is better, and otherwise, the linearization effect on the signal is poor.
However, the inventor found that in the existing digital band-limited predistortion technology, the accuracy of the power amplifier model obtained after the algorithm modeling proposed so far is not high, so that the effect of the linearization processing on the signal is reduced.
Disclosure of Invention
An object of the embodiments of the present invention is to provide a signal processing method for a band-limited predistortion system and a band-limited predistortion system, so as to improve the effect of linearization processing on a signal. The specific technical scheme is as follows:
in a first aspect, an embodiment of the present invention provides a signal processing method for a band-limited predistortion system, where the signal processing method is applied to the band-limited predistortion system, and the band-limited predistortion system includes: the device comprises a predistorter, a digital-to-analog conversion and up-conversion module, a power amplifier, a coupler, a filter, an analog-to-digital conversion and down-conversion module and a modeler; the predistorter, the digital-to-analog conversion and up-conversion module, the power amplifier, the coupler, the filter, the analog-to-digital conversion and down-conversion module and the modeler are sequentially connected; the modeling device is connected with the predistorter; the method comprises the following steps:
the modeling device obtains a historical original signal input into the digital-to-analog conversion and up-conversion module, a historical feedback signal output by the analog-to-digital conversion and down-conversion module, a baseband response of the filter and a total order of the filter, wherein the historical feedback signal is a signal output by the historical original signal after passing through the digital-to-analog conversion and up-conversion module, the power amplifier, the coupler, the filter and the analog-to-digital conversion and down-conversion module;
the modeling device determines model parameters of a power amplifier model to be established based on a historical original signal, a historical feedback signal, a baseband response of a filter, a total order of the filter and a preset band-limited pre-distortion system model;
the modeler establishes a power amplifier model based on the model parameters; determining a predistortion model corresponding to the predistorter based on the power amplifier model and the historical original signal;
the predistortion device adopts a predistortion model to perform predistortion treatment on an original signal to be distorted, and inputs a signal to be amplified after the predistortion treatment to the power amplifier;
and the power amplifier amplifies the pre-distorted signal to be amplified output by the pre-distorter.
Optionally, before determining a model parameter of the power amplifier model to be established based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter, and the preset band-limited predistortion system model, the method further includes:
synchronizing the historical original signal and the historical feedback signal to obtain a synchronized historical original signal and a synchronized historical feedback signal;
determining model parameters of a power amplifier model to be established based on a historical original signal, a historical feedback signal, a baseband response of a filter, a total order of the filter and a preset band-limited pre-distortion system model, wherein the model parameters comprise:
and determining model parameters of a power amplifier model to be established based on the synchronized historical original signal, the synchronized historical feedback signal, the baseband response of the filter, the total order of the filter and a preset band-limited pre-distortion system model.
Optionally, the band-limited predistortion system model is preset as follows:
Figure BDA0003074352970000031
wherein the content of the first and second substances,
Figure BDA0003074352970000032
for the feedback signal, w (P) is the baseband response of the filter, P is the total order of the filter, L a ，L b And L c Respectively a preset memory depth parameter, K a ，K b And K c Respectively a preset order number, M b For a preset delay depth, M c The depth is a preset leading depth; x (n-l) 1 P) as the l-th of the original signal x (n) 1 + p time-delayed signals, x (n-l) 2 P) as the l-th of the original signal x (n) 2 + p time-delayed signals, x (n-l) 2 -m 2 P) as the l-th of the original signal x (n) 2 +m 2 + p time-delayed signals, x (n-l) 3 P) as the l-th of the original signal x (n) 3 + p time delayed signals，x(n-l 3 +m 3 P) as the l-th of the original signal x (n) 3 -m 3 + p time-delayed signals, r 1l ，r 2l ，r 3l ，
Figure BDA0003074352970000033
And
Figure BDA0003074352970000034
presetting model parameters of a band-limited predistortion system model;
the power amplifier model to be established is as follows:
Figure BDA0003074352970000035
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003074352970000036
full band signal corresponding to the original signal, x (n-l), output by the power amplifier 1 ) Is the l-th of the original signal x (n) 1 A time-delayed signal, x (n-l) 2 ) Is the l-th of the original signal x (n) 2 A time-delayed signal, x (n-l) 2 -m 2 ) Is the l-th of the original signal x (n) 2 +m 2 A time-delayed signal, x (n-l) 3 ) Is the l-th of the original signal x (n) 3 A time-delayed signal, x (n-l) 3 +m 3 ) Is the l-th of the original signal x (n) 3 -m 3 A time delayed signal.
Optionally, determining a model parameter of the power amplifier model to be established based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter, and the preset band-limited predistortion system model, includes:
obtaining model parameters of a preset band-limited predistortion system model
Figure BDA0003074352970000041
And
Figure BDA0003074352970000042
wherein the initial value is a preset value;
model parameters based on historical original signals, historical feedback signals, baseband response of filters, total order of filters and preset band-limited pre-distortion system model
Figure BDA0003074352970000043
And
Figure BDA0003074352970000044
through the preset band-limited pre-distortion system model, the model parameter r of the preset band-limited pre-distortion system model is calculated 1l ，r 2l And r 3l An iteration value of (d);
model parameter r based on historical original signal, historical feedback signal, baseband response of filter, total order of filter and preset band-limited predistortion system model 1l ，r 2l ，r 3l Calculating the model parameters of the preset band-limited predistortion system model through the preset band-limited predistortion system model
Figure BDA0003074352970000045
And
Figure BDA0003074352970000046
an iteration value of (d);
model parameter r of pre-set band-limited pre-distortion system model 1l ，r 2l ，r 3l ，
Figure BDA0003074352970000047
And
Figure BDA0003074352970000048
when the iteration value reaches the preset output condition, the model parameter r of the preset band-limited predistortion system model is set 1l ，r 2l ，r 3l ，
Figure BDA0003074352970000049
And
Figure BDA00030743529700000410
as a model parameter of the power amplifier model to be built;
otherwise, presetting the model parameters of the band-limited predistortion system model
Figure BDA00030743529700000411
And
Figure BDA00030743529700000412
as a model parameter of a pre-defined pre-distortion system model
Figure BDA00030743529700000413
And
Figure BDA00030743529700000414
and performing model parameters based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter, and the preset band-limited pre-distortion system model
Figure BDA00030743529700000415
And
Figure BDA00030743529700000416
through the preset band-limited pre-distortion system model, the model parameter r of the preset band-limited pre-distortion system model is calculated 1l ，r 2l And r 3l The iteration value of (c).
Optionally, the model parameters are based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter, and the preset band-limited pre-distortion system model
Figure BDA00030743529700000417
And
Figure BDA00030743529700000418
calculating the preset band-limit predistortion through a preset band-limit predistortion system modelModel parameters r of distortion system model 1l ，r 2l And r 3l Includes:
model parameters based on historical original signals, historical feedback signals, baseband response of filters, total order of filters and preset band-limited pre-distortion system model
Figure BDA00030743529700000419
And
Figure BDA00030743529700000420
through the preset band-limited predistortion system model, and the least square method is adopted to calculate the model parameter r of the preset band-limited predistortion system model 1l ，r 2l And r 3l An iteration value of (d);
model parameter r based on historical original signal, historical feedback signal, baseband response of filter, total order of filter and preset band-limited predistortion system model 1l ，r 2l ，r 3l Calculating the model parameters of the preset band-limited predistortion system model through the preset band-limited predistortion system model
Figure BDA0003074352970000051
And
Figure BDA0003074352970000052
comprises:
model parameter r based on historical original signal, historical feedback signal, baseband response of filter, total order of filter and preset band-limited predistortion system model 1l ，r 2l ，r 3l Calculating the model parameters of the pre-set band-limited pre-distortion system model by the pre-set band-limited pre-distortion system model and adopting the least square method
Figure BDA0003074352970000053
Figure BDA0003074352970000054
And
Figure BDA0003074352970000055
the iteration value of (c).
In a second aspect, an embodiment of the present invention further provides a band-limited predistortion system, where the band-limited predistortion system includes: the device comprises a predistorter, a digital-to-analog conversion and up-conversion module, a power amplifier, a coupler, a filter, an analog-to-digital conversion and down-conversion module and a modeler; the predistorter, the digital-to-analog conversion and up-conversion module, the power amplifier, the coupler, the filter, the analog-to-digital conversion and down-conversion module and the modeler are sequentially connected; the modeling device is connected with the predistorter;
a modeler to: acquiring a historical original signal input into a digital-to-analog conversion and up-conversion module, a historical feedback signal output by an analog-to-digital conversion and down-conversion module, a baseband response of a filter and a total order of the filter, wherein the historical feedback signal is a signal output by the historical original signal after passing through the digital-to-analog conversion and up-conversion module, a power amplifier, a coupler, the filter and the analog-to-digital conversion and down-conversion module;
a modeler, further to: determining model parameters of a power amplifier model to be established based on a historical original signal, a historical feedback signal, a baseband response of a filter, a total order of the filter and a preset band-limited pre-distortion system model;
a modeler, further to: establishing a power amplifier model based on the model parameters; determining a predistortion model corresponding to the predistorter based on the power amplifier model and the historical original signal;
the predistorter is used for carrying out predistortion treatment on an original signal to be distorted by adopting a predistortion model and inputting a signal to be amplified after the predistortion treatment to the power amplifier;
and the power amplifier is used for amplifying the pre-distorted signal to be amplified output by the pre-distorter.
Optionally, the modeler is further configured to:
before determining model parameters of a power amplifier model to be established based on a historical original signal, a historical feedback signal, a baseband response of a filter, a total order of the filter and a preset band-limited pre-distortion system model, synchronizing the historical original signal and the historical feedback signal to obtain the synchronized historical original signal and the synchronized historical feedback signal;
a modeler, further to:
and determining model parameters of a power amplifier model to be established based on the synchronized historical original signal, the synchronized historical feedback signal, the baseband response of the filter, the total order of the filter and a preset band-limited pre-distortion system model.
Optionally, the pre-set band-limited pre-distortion system model is as follows:
Figure BDA0003074352970000061
wherein the content of the first and second substances,
Figure BDA0003074352970000062
for the feedback signal, w (P) is the baseband response of the filter, P is the total order of the filter, L a ，L b And L c Respectively a preset memory depth parameter, K a ，K b And K c Respectively a preset order, M b For a preset delay depth, M c The depth is a preset leading depth; x (n-l) 1 P) is the l-th of the original signal x (n) 1 + p time-delayed signals, x (n-l) 2 P) as the l-th of the original signal x (n) 2 + p time-delayed signals, x (n-l) 2 -m 2 P) as the l-th of the original signal x (n) 2 +m 2 + p time-delayed signals, x (n-l) 3 P) as the l-th of the original signal x (n) 3 + p time-delayed signals, x (n-l) 3 +m 3 P) as the l-th of the original signal x (n) 3 -m 3 + p time-delayed signals, r 1l ，r 2l ，r 3l ，
Figure BDA0003074352970000063
And
Figure BDA0003074352970000064
presetting model parameters of a band-limited predistortion system model;
the power amplifier model to be established is as follows:
Figure BDA0003074352970000071
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003074352970000072
full band signal corresponding to the original signal, x (n-l), output by the power amplifier 1 ) Is the l-th of the original signal x (n) 1 A time-delayed signal, x (n-l) 2 ) Is the l-th of the original signal x (n) 2 A time-delayed signal, x (n-l) 2 -m 2 ) Is the l-th of the original signal x (n) 2 +m 2 A time-delayed signal, x (n-l) 3 ) Is the l-th of the original signal x (n) 3 A time-delayed signal, x (n-l) 3 +m 3 ) Is the l-th of the original signal x (n) 3 -m 3 A time delayed signal.
Optionally, the modeler is specifically configured to:
obtaining model parameters of preset band-limited predistortion system model
Figure BDA0003074352970000073
And
Figure BDA0003074352970000074
wherein the initial value is a preset value;
model parameters based on historical original signals, historical feedback signals, baseband response of filters, total order of filters and preset band-limited pre-distortion system model
Figure BDA0003074352970000075
And
Figure BDA0003074352970000076
initial value of (2)Calculating the model parameter r of the preset band-limited predistortion system model through the preset band-limited predistortion system model 1l ，r 2l And r 3l An iteration value of (d);
model parameter r based on historical original signal, historical feedback signal, baseband response of filter, total order of filter and preset band-limited predistortion system model 1l ，r 2l ，r 3l Calculating the model parameters of the preset band-limited predistortion system model through the preset band-limited predistortion system model
Figure BDA0003074352970000077
And
Figure BDA0003074352970000078
the iteration value of (a);
model parameter r of pre-set band-limited pre-distortion system model 1l ，r 2l ，r 3l ，
Figure BDA0003074352970000079
And
Figure BDA00030743529700000710
when the iteration value reaches the preset output condition, the model parameter r of the preset band-limited predistortion system model is set 1l ，r 2l ，r 3l ，
Figure BDA00030743529700000711
And
Figure BDA00030743529700000712
as a model parameter of the power amplifier model to be built;
otherwise, presetting the model parameters of the band-limited predistortion system model
Figure BDA00030743529700000713
And
Figure BDA00030743529700000714
by iteration ofModel parameters for pre-setting a band-limited pre-distortion system model
Figure BDA00030743529700000715
And
Figure BDA00030743529700000716
and performing model parameters based on the historical raw signal, the historical feedback signal, the baseband response of the filter, the total order of the filter, and the preset band-limited pre-distortion system model
Figure BDA0003074352970000081
And
Figure BDA0003074352970000082
through the preset band-limited predistortion system model, the model parameter r of the preset band-limited predistortion system model is calculated 1l ，r 2l And r 3l The iteration value of (1).
Optionally, the modeler is specifically configured to:
model parameters based on historical original signals, historical feedback signals, baseband response of filters, total order of filters and preset band-limited pre-distortion system model
Figure BDA0003074352970000083
And
Figure BDA0003074352970000084
through the preset band-limited predistortion system model, and the least square method is adopted to calculate the model parameter r of the preset band-limited predistortion system model 1l ，r 2l And r 3l An iteration value of (d);
model parameter r based on historical original signal, historical feedback signal, baseband response of filter, total order of filter and preset band-limited predistortion system model 1l ，r 2l ，r 3l Calculating the model parameters of the pre-set band-limited pre-distortion system model by a pre-set band-limited pre-distortion system model and adopting a least square method
Figure BDA0003074352970000085
Figure BDA0003074352970000086
And
Figure BDA0003074352970000087
the iteration value of (c).
The embodiment of the invention has the following beneficial effects:
in the signal processing method for the band-limited pre-distortion system and the band-limited pre-distortion system provided by the embodiment of the invention, the modeler can firstly obtain the historical original signal input into the digital-to-analog conversion and up-conversion module, the historical feedback signal output by the analog-to-digital conversion and down-conversion module, the baseband response of the filter and the total order of the filter, and then the modeler determines the model parameters of the preset band-limited pre-distortion system model based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the preset band-limited pre-distortion system model, so that the model parameters of the preset band-limited pre-distortion system model can be determined as the model parameters of the power amplifier model to be established, and the power amplifier model can be established based on the model parameters of the power amplifier model to be established; after the power amplifier model is established, the full-band signal corresponding to the historical original signal can be obtained through the power amplifier model, a predistortion model can be established according to the historical original signal and the calculated full-band signal, and finally, a signal obtained by the signal to be distorted through the predistorter and the power amplifier is linear with the signal to be distorted. In the embodiment of the invention, when the power amplifier model is established, the influence of the order of the filter on the memory depth of the model is considered, and the coefficient related to the memory depth of the model is disassembled for calculation, so that the process of solving the power amplifier model is not easily interfered by the filter, the power amplifier model obtained by modeling is more accurate, and the linearization effect is better when the power amplifier model and the predistortion model are used for carrying out predistortion and amplification on signals. And when the bandwidth of the filter is narrower, a more accurate power amplifier model can be obtained compared with the traditional method, so that the sampling rate of a necessary analog-digital converter of a feedback loop can be reduced, and the engineering cost is saved. Of course, not all of the above advantages need be achieved in the practice of any one product or method of the present invention.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other embodiments can be obtained by using the drawings without creative efforts.
Fig. 1 is a schematic diagram of a band-limited predistortion system in the prior art;
fig. 2 is a flowchart of a first implementation of a signal processing method for a band-limited pre-distortion system according to an embodiment of the present invention;
fig. 3 is a flowchart of a second implementation of a signal processing method for a band-limited pre-distortion system according to an embodiment of the present invention;
fig. 4 is a flowchart of a third implementation of a signal processing method for a band-limited predistortion system according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived from the embodiments given herein by one of ordinary skill in the art, are within the scope of the invention.
In the prior art, when preprocessing and amplifying a signal, a band-limited predistortion system shown in fig. 1 is usually adopted, and as shown in fig. 1, the system mainly includes: predistorter 110, digital-to-analog conversion and up-conversion module 120, power amplifier 130, coupler 140, filter150. An analog-to-digital conversion and down-conversion module 160, and a modeler 170. The predistorter 110, the digital-to-analog conversion and up-conversion module 120, the power amplifier 130, the coupler 140, the filter 150, the analog-to-digital conversion and down-conversion module 160 and the modeler 170 are connected in sequence; modeler 170 is also coupled to predistorter 110; the input signal x (n) passes through the predistorter 110 to obtain a predistortion signal Z (n), and the predistortion signal Z (n) is converted and up-converted by the digital-to-analog conversion and up-conversion module 120 to become the input signal Z (n) of the power amplifier 130 RF (t) obtaining an output signal y (t) after being amplified by the power amplifier 130, inputting the output signal y (t) to the coupler 140, dividing the output signal y (t) output by the power amplifier into two paths of signals by the coupler 140, wherein one path of signal is used for output, the other path of signal passes through the coupler 140 with the gain of 1/k (k is the expected gain of the power amplifier) and then is input into the filter 150, and the signal filtered by the filter 150
Figure BDA0003074352970000101
After the analog-to-digital conversion and down-conversion module 160, the signal becomes a feedback loop output signal
Figure BDA0003074352970000102
After signal
Figure BDA0003074352970000103
Enters the modeler 170 and implements the computation of the predistorter coefficients in conjunction with the original input x (n) so that linearization of the signal can be achieved.
However, in the prior art, when the filter 150 passband is very narrow, this results in a rapid degradation of modeling accuracy for the power amplifier model as the filter passband narrows. Since the bandwidth of the filter 150 is directly related to the lowest sampling rate of the analog-to-digital conversion and down-conversion module 160 in the feedback loop of the bandlimited digital predistortion technique, in the prior art, when the sampling rate of the analog-to-digital conversion and down-conversion module 160 is low, a ill-conditioned matrix may occur in the calculation process, which may result in a decrease in the accuracy of modeling the power amplifier model, and thus may result in a decrease in the effect of linear processing on the signal.
In order to solve the problems in the prior art, embodiments of the present invention provide a signal processing method for a band-limited pre-distortion system and a band-limited pre-distortion system, so as to improve the effect of linear processing on a signal.
Next, a signal processing method for a band-limited pre-distortion system according to an embodiment of the present invention is described, as shown in fig. 2, which is a schematic flow chart of a first implementation manner of the signal processing method for the band-limited pre-distortion system according to the embodiment of the present invention, and the method can be applied to the band-limited pre-distortion system shown in fig. 1. The method can comprise the following steps:
s210, a modeler acquires a historical original signal input into a digital-to-analog conversion and up-conversion module, a historical feedback signal output by an analog-to-digital conversion and down-conversion module, a baseband response of a filter and a total order of the filter, wherein the historical feedback signal is a signal output by the historical original signal after passing through the digital-to-analog conversion and up-conversion module, the power amplifier, the coupler, the filter and the analog-to-digital conversion and down-conversion module;
s220, the modeler determines model parameters of a power amplifier model to be established based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and a preset band-limited pre-distortion system model;
s230, the modeler establishes a power amplifier model based on the model parameters; determining a predistortion model corresponding to the predistorter based on the power amplifier model and the historical original signal;
s240, the predistorter performs predistortion processing on an original signal to be distorted by adopting a predistortion model, and inputs a signal to be amplified after the predistortion processing to a power amplifier;
and S250, the power amplifier amplifies the pre-distorted signal to be amplified output by the pre-distorter.
In some examples, the predistorter 110 does not perform predistortion in the initial stage after the signal is input into the band-limited predistortion system, so the predistorter 110 can be assumed to be a line firstA linear component, therefore, a signal input into the predistorter 110 is equal to a signal output by the predistorter, that is, x (n) = Z (n), the signal passes through the predistorter 110 to obtain a predistortion signal Z (n), and the predistortion signal Z (n) passes through the digital-to-analog conversion and frequency up conversion module 120 to become an input signal Z (n) of the power amplifier 130 RF (t), the signal is amplified by the power amplifier 130 to obtain an output signal y (t), the output signal y (t) passes through the coupler 140 with a gain of 1/k (k is the desired gain of the power amplifier), and then is input into the filter 150, and the signal filtered by the filter 150
Figure BDA0003074352970000111
After passing through the analog-to-digital conversion and down-conversion module 160, the signal becomes the output signal of the feedback loop
Figure BDA0003074352970000112
Therefore, after the historical original signal is input to the band-limited pre-distortion system, a historical feedback signal corresponding to the historical original signal output by the down-conversion module 160 can be obtained through analog-to-digital conversion.
In some examples, the digital-to-analog conversion and frequency up-conversion module 120 includes a digital-to-analog converter and an up-converter, and the analog-to-digital conversion and frequency down-conversion module 160 includes an analog-to-digital converter and a down-converter.
In order to improve the modeling accuracy of the power amplifier model and further improve the effect of the linearization processing on the signal, here, the historical original signal input into the digital-to-analog converter, the baseband response of the filter, and the total order of the filter may also be obtained, where the baseband response of the filter is: the rf bandpass filter converts to a unit impulse response of a finite length impulse response filter at an equivalent baseband.
After the historical original signal, the historical feedback signal, the baseband response of the filter and the total order of the filter are obtained, the model parameters of the preset band-limited pre-distortion system model can be determined based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the preset band-limited pre-distortion system model, and then the model parameters of the preset band-limited pre-distortion system model are used as the model parameters of the power amplifier model to be established, so that the power amplifier model can be established based on the model parameters of the power amplifier model to be established. After the power amplifier model is established, a predistortion model corresponding to the predistorter can be determined based on the power amplifier model and historical original signals;
in some examples, when determining a predistortion model corresponding to the predistorter based on the power amplifier model and the historical raw signal, the established power amplifier model and the historical raw signal may be used to calculate a full-band output signal of the power amplifier, and then a predistortion model may be constructed from the historical raw signal and the calculated full-band output signal.
In some examples, the basis function used by the predistortion model is the same as the basis function of the power amplifier model, and therefore, when the predistortion model corresponding to the predistorter is determined based on the power amplifier model and the historical original signal, the full-band output of the power amplifier obtained based on the power amplifier model and the historical original signal may be used to calculate the parameters used by the predistortion model, and after the parameters used by the predistortion model are obtained by calculation, the parameters may be substituted into the formula used by the predistortion model, so that the predistortion model may be obtained.
After the predistortion model and the power amplification model are obtained, the predistorter can perform predistortion processing on an original signal to be distorted by adopting the predistortion model, and input the signal to be amplified after the predistortion processing to the power amplifier; the power amplifier may amplify the pre-distorted signal to be amplified output by the pre-distorter. Finally, the amplified signal output by the power amplifier is linear with the original input signal.
In the signal processing method for the band-limited pre-distortion system provided by the embodiment of the invention, the modeler can firstly obtain the historical original signal input into the digital-to-analog conversion and up-conversion module, the historical feedback signal output by the digital-to-analog conversion and down-conversion module, the baseband response of the filter and the total order of the filter, and then the modeler determines the model parameters of the preset band-limited pre-distortion system model based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the preset band-limited pre-distortion system model, so that the model parameters of the preset band-limited pre-distortion system model can be determined as the model parameters of the power amplifier model to be established, and the power amplifier model can be established based on the model parameters of the power amplifier model to be established; after the power amplifier model is established, the full-band signal corresponding to the historical original signal can be obtained through the power amplifier model, a predistortion model can be established according to the historical original signal and the calculated full-band signal, and finally, a signal obtained by the signal to be distorted through the predistorter and the power amplifier is linear with the signal to be distorted. In the embodiment of the invention, when the power amplifier model is established, the influence of the order of the filter on the memory depth of the model is considered, and the coefficient related to the memory depth of the model is disassembled and calculated, so that the process of solving the power amplifier model is not easily interfered by the filter, the power amplifier model obtained by modeling is more accurate, and the linearization effect is better when the power amplifier model and the predistortion model are used for carrying out predistortion and amplification treatment on signals. And when the bandwidth of the filter is narrower, a more accurate power amplifier model can be obtained compared with the traditional method, so that the sampling rate of a necessary analog-digital converter of a feedback loop can be reduced, and the engineering cost is saved.
On the basis of the signal processing method for the band-limited predistortion system shown in fig. 2, an embodiment of the present invention further provides a possible implementation manner, as shown in fig. 3, which is a flowchart of a second implementation manner of the signal processing method for the band-limited predistortion system according to the embodiment of the present invention, and the method may include:
s310, a modeler acquires a historical original signal input into a digital-to-analog conversion and up-conversion module, a historical feedback signal output by an analog-to-digital conversion and down-conversion module, a baseband response of a filter and a total order of the filter, wherein the historical feedback signal is a signal output by the historical original signal after passing through the digital-to-analog conversion and up-conversion module, the power amplifier, the coupler, the filter and the analog-to-digital conversion and down-conversion module;
s320, synchronizing the historical original signal and the historical feedback signal to obtain a synchronized historical original signal and a synchronized historical feedback signal;
s330, the modeler determines a power amplifier model to be established based on the synchronized historical original signal, the synchronized historical feedback signal, the baseband response of the filter, the total order of the filter and a preset band-limited pre-distortion system model;
s340, the modeler establishes a power amplifier model based on the model parameters; determining a predistortion model corresponding to the predistorter based on the power amplifier model and the historical original signal;
s350, the predistorter performs predistortion processing on an original signal to be distorted by adopting a predistortion model, and inputs a signal to be amplified after the predistortion processing to a power amplifier;
and S360, the power amplifier amplifies the pre-distorted signal to be amplified output by the pre-distorter.
In some examples, after obtaining the historical raw signal and the historical feedback signal, the historical raw signal and the historical feedback signal may be synchronized first in order to improve the accuracy of modeling the power amplifier model because of the possible lack of synchronization between the historical raw signal and the historical feedback signal.
In still other examples, the historical raw signal and the historical feedback signal may be synchronized using prior art signal synchronization techniques. And will not be described in detail herein.
After the historical original signal and the historical feedback signal are synchronized, the synchronized historical original signal and the synchronized historical feedback signal can be obtained, so that the modeler can determine model parameters of the preset band-limited pre-distortion system model based on the synchronized historical original signal, the synchronized historical feedback signal, the baseband response of the filter, the total order of the filter and the preset band-limited pre-distortion system model, then can use the model parameters of the preset band-limited pre-distortion system model as the model parameters of the power amplifier model to be established, and further can establish the power amplifier model based on the model parameters of the power amplifier model to be established.
It can be understood that steps S310 and S340 to S360 in the embodiment of the present invention are the same as or similar to steps S210 and S230 to S250 in the first implementation, and are not described herein again.
On the basis of the signal processing method for the band-limited predistortion system shown in fig. 2, an embodiment of the present invention further provides a possible implementation manner, as shown in fig. 4, which is a flowchart of a third implementation manner of the signal processing method for the band-limited predistortion system according to the embodiment of the present invention, and the method may include:
s401, a modeler acquires a historical original signal input into a digital-to-analog converter, a historical feedback signal output by an analog-to-digital conversion and down-conversion module, a baseband response of a filter and a total order of the filter, wherein the historical feedback signal is a signal output by the historical original signal after passing through the digital-to-analog conversion and up-conversion module, a power amplifier, a coupler, the filter and the analog-to-digital conversion and down-conversion module;
s402, the modeler obtains model parameters of a preset band-limited predistortion system model
Figure BDA0003074352970000141
And
Figure BDA0003074352970000142
wherein the initial value is a preset value;
s403, based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the model parameters of the preset band-limited pre-distortion system model
Figure BDA0003074352970000143
And
Figure BDA0003074352970000144
by pre-setting the band-limited predistortion systemModel, calculating model parameter r of the pre-set band-limited pre-distortion system model 1l ，r 2l And r 3l An iteration value of (d);
s404, based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the model parameter r of the preset band-limited predistortion system model 1l ，r 2l And r 3l Calculating the model parameters of the pre-set band-limited pre-distortion system model through the pre-set band-limited pre-distortion system model
Figure BDA0003074352970000145
And
Figure BDA0003074352970000146
an iteration value of (d);
s405, judging the model parameter r of the preset band-limited predistortion system model 1l ，r 2l ，r 3l ，
Figure BDA0003074352970000147
And
Figure BDA0003074352970000148
whether the iteration value reaches a preset output condition, if so, executing step S406, otherwise, executing step S407;
s406, presetting the model parameter r of the band-limited predistortion system model 1l ，r 2l ，r 3l ，
Figure BDA0003074352970000149
And
Figure BDA00030743529700001410
as a model parameter of the power amplifier model to be established; and executing step S408;
s407, presetting model parameters of the band-limited predistortion system model
Figure BDA00030743529700001411
And
Figure BDA00030743529700001412
as a model parameter of a pre-defined pre-distortion system model
Figure BDA00030743529700001413
And
Figure BDA00030743529700001414
and step S404 is executed;
in some examples, the above-mentioned pre-set band-limited pre-distortion system model is as follows:
Figure BDA0003074352970000151
wherein the content of the first and second substances,
Figure BDA0003074352970000152
for the feedback signal, w (P) is the baseband response of the filter, P is the total order of the filter, L a ，L b And L c Respectively a preset memory depth parameter, K a ，K b And K c Respectively a preset order number, M b For a preset delay depth, M c The depth is a preset leading depth; x (n-l) 1 P) as the l-th of the original signal x (n) 1 + p time-delayed signals, x (n-l) 2 P) as the l-th of the original signal x (n) 2 + p time-delayed signals, x (n-l) 2 -m 2 P) as the l-th of the original signal x (n) 2 +m 2 + p time-delayed signals, x (n-l) 3 P) as the l-th of the original signal x (n) 3 + p time-delayed signals, x (n-l) 3 +m 3 P) as the l-th of the original signal x (n) 3 -m 3 + p time-delayed signals, r 1l ，r 2l ，r 3l ，
Figure BDA0003074352970000153
And
Figure BDA0003074352970000154
model parameters of a preset band-limited predistortion system model are set;
wherein, the L a ，L b And L c Memory depth parameter, K, for both the pre-set band-limited pre-distortion system model and the power amplifier model to be built a ，K b And K c Order, M, of both the pre-set band-limited pre-distortion system model and the power amplifier model to be built b Delay depth, M, for presetting a band-limited predistortion system model and a power amplifier model to be established c The leading depth of the band-limited predistortion system model and the power amplifier model to be established is preset.
Therefore, when determining the model parameters of the power amplifier model to be established based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the preset band-limited pre-distortion system model, the model parameters can be calculated in an iterative manner.
Specifically, the parameters of the model may be set
Figure BDA0003074352970000155
And
Figure BDA0003074352970000156
then based on the initial values of the model parameters
Figure BDA0003074352970000157
And
Figure BDA0003074352970000158
the initial value, the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and a preset band-limited pre-distortion system model to calculate r in the model parameter 1l ，r 2l And r 3l The iteration value of (2).
In some examples, the above-described basis function formula may be abbreviated as follows:
Figure BDA0003074352970000161
wherein:
Figure BDA0003074352970000162
Figure BDA0003074352970000163
Figure BDA0003074352970000164
further, the above-mentioned basis function formula can be further abbreviated as the following matrix form:
Figure BDA0003074352970000165
thus, R can be represented as:
Figure BDA0003074352970000166
wherein:
Figure BDA0003074352970000167
Figure BDA0003074352970000168
where T represents transpose and H represents conjugate transpose.
And since R = [ R ] 11 ,r 12 ,...,r 21 ,r 22 ,...,r 31 ,r 32 ...] T Thus, r in the model parameters can be obtained 1l ，r 2l And r 3l The iteration value of (c).
In some examples, the calculation may be performed by a least squares methodObtaining r in the model parameter 1l ，r 2l And r 3l The iteration value of (c).
In some examples, the above-described basis function formula may also be abbreviated as follows:
Figure BDA0003074352970000169
wherein the content of the first and second substances,
Figure BDA0003074352970000171
Figure BDA0003074352970000172
Figure BDA0003074352970000173
further, the above-mentioned basis function formula can be further abbreviated as the following matrix form:
Figure BDA0003074352970000174
thus, T can be expressed as:
Figure BDA0003074352970000175
wherein:
Figure BDA0003074352970000176
and since T = [ a ] 1 ，…，b 11 ，…，c 11 ，…] T Thus, the model parameters can be obtained
Figure BDA0003074352970000177
And
Figure BDA0003074352970000178
the iteration value of (2).
In some examples, the model parameters can be calculated by least squares
Figure BDA0003074352970000179
And
Figure BDA00030743529700001710
the iteration value of (2).
Obtaining the model parameter r of the preset band-limited predistortion system model 1l ，r 2l ，r 3l ，
Figure BDA00030743529700001711
And
Figure BDA00030743529700001712
after the iteration value is obtained, whether the iteration value of the model parameter reaches a preset output condition can be judged. Wherein the preset output condition may be a preset number of iterations.
When the iteration value of the model parameter does not reach the preset output condition, the model parameter of the preset band-limited predistortion system model can be set
Figure BDA00030743529700001713
And
Figure BDA00030743529700001714
as a model parameter of a pre-defined pre-distortion system model
Figure BDA00030743529700001715
And
Figure BDA00030743529700001716
and step S340 is performed to continue the iterative calculation.
When the iteration value of the model parameter reaches the preset output condition, the preset band-limited predistortion system can be setModel parameters r of the system model 1l ，r 2l ，r 3l ，
Figure BDA00030743529700001717
And
Figure BDA00030743529700001718
the iteration value of (1) is used as a model parameter of the power amplifier model to be established, so that the modeler can establish the power amplifier model based on the model parameter of the power amplifier model to be established;
s408, the modeler establishes a power amplifier model based on model parameters of the power amplifier model to be established; determining a predistortion model corresponding to the predistorter based on the power amplifier model and the historical original signal;
s409, the predistorter performs predistortion processing on the original signal by adopting a predistortion model, and inputs a signal to be amplified after the predistortion processing to a power amplifier;
and S410, the power amplifier amplifies the pre-distorted signal to be amplified output by the pre-distorter.
In some examples, the power amplifier model to be built is the following equation:
Figure BDA0003074352970000181
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003074352970000182
full band signal corresponding to the original signal, x (n-l), output by the power amplifier 1 ) Is the l-th of the original signal x (n) 1 A time-delayed signal, x (n-l) 2 ) Is the l-th of the original signal x (n) 2 A time delay signal, x (n-l) 2 -m 2 ) Is the l-th of the original signal x (n) 2 +m 2 A time-delayed signal, x (n-l) 3 ) Is the l-th of the original signal x (n) 3 A time delay signal, x (n-l) 3 +m 3 ) Is the l-th of the original signal x (n) 3 -m 3 A time delayed signal.
Therefore, when the power amplifier model is built based on the model parameters, the calculated values of the model parameters of the power amplifier model to be built may be used instead of the parameters in the above formula of the power amplifier model to be built, so that the power amplifier model may be built.
It can be understood that steps S401, S408, and S409 in the embodiment of the present invention are the same as or similar to steps S210, S230, and S240 in the first implementation manner in the embodiment of the present invention, and are not repeated herein.
Corresponding to the above method embodiment, an embodiment of the present invention further provides a band-limited predistortion system, where a structure of the band-limited predistortion system is the same as that of the band-limited predistortion system shown in fig. 1, and as shown in fig. 1, the band-limited predistortion system is a schematic structural diagram of the band-limited predistortion system according to the embodiment of the present invention, and the band-limited predistortion system may include: a predistorter 110, a digital-to-analog conversion and up-conversion module 120, a power amplifier 130, a coupler 140, a filter 150, an analog-to-digital conversion and down-conversion module 160, and a modeler 170; the predistorter 110, the digital-to-analog conversion and up-conversion module 120, the power amplifier 130, the coupler 140, the filter 150, the analog-to-digital conversion and down-conversion module 160 and the modeler 170 are connected in sequence; modeler 170 is also coupled to predistorter 110;
a modeler 170 configured to: acquiring a historical original signal input into the digital-to-analog conversion and up-conversion module 120, a historical feedback signal output by the analog-to-digital conversion and down-conversion module 160, a baseband response of the filter 150, and a total order of the filter 150, wherein the historical feedback signal is a signal output by the historical original signal after passing through the digital-to-analog conversion and up-conversion module 120, the power amplifier 130, the coupler 140, the filter 150, and the analog-to-digital conversion and down-conversion module 160;
modeler 170, further configured to: determining model parameters of a power amplifier model to be established based on the historical original signal, the historical feedback signal, the baseband response of the filter 150, the total order of the filter 150 and a preset band-limited pre-distortion system model;
modeler 170, further configured to: establishing a power amplifier model based on the model parameters; determining a predistortion model corresponding to the predistorter 110 based on the power amplifier model and the historical original signal;
the predistorter 110 is configured to perform predistortion processing on an original signal to be distorted by using a predistortion model, and input a signal to be amplified after predistortion obtained by the processing to the power amplifier 130;
and the power amplifier 130 is configured to amplify the pre-distorted signal to be amplified output by the pre-distorter 110.
In the bandwidth-limited predistortion system provided by the embodiment of the invention, a modeler can firstly obtain a historical original signal input into a digital-to-analog conversion and up-conversion module, a historical feedback signal output by an analog-to-digital conversion and down-conversion module, a baseband response of a filter and a total order of the filter, and then the modeler determines a model parameter of a preset bandwidth-limited predistortion system model based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the preset bandwidth-limited predistortion system model, so that the model parameter of the preset bandwidth-limited predistortion system model can be determined as the model parameter of a power amplifier model to be established, and a power amplifier model can be established based on the model parameter of the power amplifier model to be established; after the power amplifier model is established, the full-band signal corresponding to the historical original signal can be obtained through the power amplifier model, a predistortion model can be established according to the historical original signal and the calculated full-band signal, and finally, a signal obtained by the signal to be distorted through the predistorter and the power amplifier is linear with the signal to be distorted. In the embodiment of the invention, when the power amplifier model is established, the influence of the order of the filter on the memory depth of the model is considered, and the coefficient related to the memory depth of the model is disassembled and calculated, so that the process of solving the power amplifier model is not easily interfered by the filter, the power amplifier model obtained by modeling is more accurate, and the linearization effect is better when the power amplifier model and the predistortion model are used for carrying out predistortion and amplification treatment on signals. And when the bandwidth of the filter is narrower, a more accurate power amplifier model can be obtained compared with the traditional method, so that the sampling rate of a necessary analog-digital converter of a feedback loop can be reduced, and the engineering cost is saved.
In some examples, modeler 170, is further to:
before determining a model parameter of a power amplifier model to be established based on a historical original signal, a historical feedback signal, a baseband response of a filter 150, a total order of the filter 150 and a preset band-limited pre-distortion system model, synchronizing the historical original signal and the historical feedback signal to obtain a synchronized historical original signal and a synchronized historical feedback signal;
modeler 170, further configured to:
and determining model parameters of the power amplifier model to be established based on the synchronized historical original signal, the synchronized historical feedback signal, the baseband response of the filter 150, the total order of the filter 150 and the preset band-limited pre-distortion system model.
In some examples, the pre-set band-limited pre-distortion system model is the following equation:
Figure BDA0003074352970000201
wherein the content of the first and second substances,
Figure BDA0003074352970000202
for the feedback signal, w (P) is the baseband response of filter 150, P is the total order of filter 150, L a ，L b And L c Respectively a preset memory depth parameter, K a ，K b And K c Respectively a preset order number, M b For a preset delay depth, M c The depth is a preset leading depth; x (n-l) 1 P) is the l-th of the original signal x (n) 1 + p time-delayed signals, x (n-l) 2 P) as the l-th of the original signal x (n) 2 + p time-delayed signals, x (n-l) 2 -m 2 P) as the l-th of the original signal x (n) 2 +m 2 When + pDelayed signal between, x (n-l) 3 P) as the l-th of the original signal x (n) 3 + p time-delayed signals, x (n-l) 3 +m 3 P) is the l-th of the original signal x (n) 3 -m 3 + p time-delayed signals, r 1l ，r 2l ，r 3l ，
Figure BDA0003074352970000211
And
Figure BDA0003074352970000212
presetting model parameters of a band-limited predistortion system model;
the power amplifier model to be established is as follows:
Figure BDA0003074352970000213
wherein the content of the first and second substances,
Figure BDA0003074352970000214
full band signal corresponding to the original signal, x (n-l), output by the power amplifier 130 1 ) Is the l-th of the original signal x (n) 1 A time-delayed signal, x (n-l) 2 ) Is the l-th of the original signal x (n) 2 A time-delayed signal, x (n-l) 2 -m 2 ) Is the l-th of the original signal x (n) 2 +m 2 A time-delayed signal, x (n-l) 3 ) Is the l-th of the original signal x (n) 3 A time delay signal, x (n-l) 3 +m 3 ) Is the l-th of the original signal x (n) 3 -m 3 A time delayed signal.
In some examples, modeler 170 is specifically configured to:
obtaining model parameters of preset band-limited predistortion system model
Figure BDA0003074352970000215
And
Figure BDA0003074352970000216
wherein the initial value isA preset value;
model parameters based on historical raw signals, historical feedback signals, baseband response of filter 150, total order of filter 150, and a pre-set band-limited pre-distortion system model
Figure BDA0003074352970000217
And
Figure BDA0003074352970000218
through the preset band-limited pre-distortion system model, the model parameter r of the preset band-limited pre-distortion system model is calculated 1l ，r 2l And r 3l The iteration value of (a);
based on the historical original signal, the historical feedback signal, the baseband response of the filter 150, the total order of the filter 150 and the model parameter r of the preset band-limited pre-distortion system model 1l ，r 2l ，r 3l Calculating the model parameters of the preset band-limited predistortion system model through the preset band-limited predistortion system model
Figure BDA0003074352970000219
And
Figure BDA00030743529700002110
an iteration value of (d);
model parameter r of pre-set band-limited pre-distortion system model 1l ，r 2l ，r 3l ，
Figure BDA00030743529700002111
And
Figure BDA00030743529700002112
when the iteration value reaches the preset output condition, the model parameter r of the preset band-limited predistortion system model is set 1l ，r 2l ，r 3l ，
Figure BDA0003074352970000221
And
Figure BDA0003074352970000222
as a model parameter of the power amplifier model to be built;
otherwise, presetting the model parameters of the band-limited predistortion system model
Figure BDA0003074352970000223
And
Figure BDA0003074352970000224
as model parameters of a pre-defined bandlimited pre-distortion system model
Figure BDA0003074352970000225
And
Figure BDA0003074352970000226
and performs model parameters based on the historical raw signal, the historical feedback signal, the baseband response of the filter 150, the total order of the filter 150, and the pre-set band-limited pre-distortion system model
Figure BDA0003074352970000227
And
Figure BDA0003074352970000228
through the preset band-limited predistortion system model, the model parameter r of the preset band-limited predistortion system model is calculated 1l ，r 2l And r 3l The iteration value of (c).
In some examples, modeler 170 is specifically configured to:
model parameters based on historical raw signal, historical feedback signal, baseband response of filter 150, total order of filter 150, and pre-set band-limited pre-distortion system model
Figure BDA0003074352970000229
And
Figure BDA00030743529700002210
by pre-setting the bandwidth limit of the predistortion system moduleCalculating the model parameter r of the preset band-limited predistortion system model by adopting a least square method 1l ，r 2l And r 3l An iteration value of (d);
model parameter r based on historical raw signal, historical feedback signal, baseband response of filter 150, total order of filter 150, and preset band-limited pre-distortion system model 1l ，r 2l ，r 3l Calculating the model parameters of the pre-set band-limited pre-distortion system model by the pre-set band-limited pre-distortion system model and adopting the least square method
Figure BDA00030743529700002211
And
Figure BDA00030743529700002212
the iteration value of (2).
In the above embodiments, all or part of the implementation may be realized by software, hardware, firmware, or any combination thereof. When implemented in software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid State Disk (SSD)), among others.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.
All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. A signal processing method for a band-limited predistortion system, applied to the band-limited predistortion system, the band-limited predistortion system comprising: the device comprises a predistorter, a digital-to-analog conversion and up-conversion module, a power amplifier, a coupler, a filter, an analog-to-digital conversion and down-conversion module and a modeler; the predistorter, the digital-to-analog conversion and up-conversion module, the power amplifier, the coupler, the filter, the analog-to-digital conversion and down-conversion module and the modeler are sequentially connected; the modeling device is connected with the predistorter; the method comprises the following steps:
the modeler acquires a historical original signal input into the digital-to-analog conversion and up-conversion module, a historical feedback signal output by the analog-to-digital conversion and down-conversion module, a baseband response of the filter and a total order of the filter, wherein the historical feedback signal is a signal output by the historical original signal after passing through the digital-to-analog conversion and up-conversion module, the power amplifier, the coupler, the filter and the analog-to-digital conversion and down-conversion module;
the modeler determines model parameters of a power amplifier model to be established based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and a preset band-limited pre-distortion system model;
the modeler establishes the power amplifier model based on the model parameters; determining a predistortion model corresponding to the predistorter based on the power amplifier model and the historical original signal;
the predistorter adopts the predistortion model to perform predistortion processing on an original signal to be distorted, and inputs a signal to be amplified after the predistortion processing to the power amplifier;
and the power amplifier amplifies the pre-distorted signal to be amplified output by the pre-distorter.
2. The method of claim 1, wherein before the determining model parameters of the power amplifier model to be built based on the historical raw signal, the historical feedback signal, the baseband response of the filter, the total order of the filter, and a preset band-limited pre-distortion system model, the method further comprises:
synchronizing the historical original signal and the historical feedback signal to obtain a synchronized historical original signal and a synchronized historical feedback signal;
the determining a model parameter of a power amplifier model to be established based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and a preset band-limited predistortion system model comprises:
and determining model parameters of the power amplifier model to be established based on the synchronized historical original signal, the synchronized historical feedback signal, the baseband response of the filter, the total order of the filter and the preset band-limited pre-distortion system model.
3. The method of claim 1, wherein the pre-set band-limited pre-distortion system model is represented by the following formula:
Figure FDA0003074352960000021
wherein, the
Figure FDA0003074352960000022
For the feedback signal, w (P) is the baseband response of the filter, P is the total order of the filter, and L a Said L is b And said L c Respectively a preset memory depth parameter, K a ，K b And K c Respectively, a preset order, M b For a preset delay depth, M c The depth is a preset leading depth; the x (n-l) 1 P) is the l-th of the original signal x (n) 1 + p time-delayed signals, said x (n-l) 2 -p) is the l-th of the original signal x (n) 2 + p time-delayed signals, said x (n-l) 2 -m 2 -p) is the l-th of the original signal x (n) 2 +m 2 + p time-delayed signals, said x (n-l) 3 -p) is the l-th of the original signal x (n) 3 + p time-delayed signals, said x (n-l) 3 +m 3 -p) is the l-th of the original signal x (n) 3 -m 3 + p time-delayed signals, said r 1l ，r 2l ，r 3l ，
Figure FDA0003074352960000024
And
Figure FDA0003074352960000025
setting model parameters of the pre-set band-limited pre-distortion system model;
the power amplifier model to be established is as follows:
Figure FDA0003074352960000023
wherein, the
Figure FDA0003074352960000031
For the full band signal corresponding to the original signal output by the power amplifier, the x (n-l) 1 ) Is the l-th of the original signal x (n) 1 A time delay signal, said x (n-l) 2 ) Is the l-th of the original signal x (n) 2 A time delay signal, said x (n-l) 2 -m 2 ) Is the l-th of the original signal x (n) 2 +m 2 A time delay signal, said x (n-l) 3 ) Is the l-th of the original signal x (n) 3 A time delay signal, said x (n-l) 3 +m 3 ) Is the l-th of the original signal x (n) 3 -m 3 A time delayed signal.
4. The method of claim 3, wherein determining model parameters of a power amplifier model to be built based on the historical raw signal, the historical feedback signal, the baseband response of the filter, the total order of the filter, and a preset band-limited pre-distortion system model comprises:
obtaining the preset band-limited predistortion system modelModel parameters of
Figure FDA0003074352960000032
And
Figure FDA0003074352960000033
wherein the initial value is a preset value;
based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the model parameters of the preset band-limited pre-distortion system model
Figure FDA0003074352960000034
And
Figure FDA0003074352960000035
through the preset band-limited pre-distortion system model, calculating the model parameter r of the preset band-limited pre-distortion system model 1l ，r 2l And r 3l An iteration value of (d);
based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the model parameter r of the preset band-limited pre-distortion system model 1l ，r 2l ，r 3l Calculating the model parameters of the preset band-limited predistortion system model through the preset band-limited predistortion system model
Figure FDA0003074352960000036
And
Figure FDA0003074352960000037
an iteration value of (d);
model parameter r of the preset band-limited predistortion system model 1l ，r 2l ，r 3l ，
Figure FDA0003074352960000038
And
Figure FDA0003074352960000039
when the iteration value of the preset band-limited pre-distortion system model reaches a preset output condition, the model parameter r of the preset band-limited pre-distortion system model is set 1l ，r 2l ，r 3l ，
Figure FDA00030743529600000310
And
Figure FDA00030743529600000311
as a model parameter of the power amplifier model to be built;
otherwise, model parameters of the preset band-limited predistortion system model are set
Figure FDA00030743529600000312
And
Figure FDA00030743529600000313
as a model parameter of the pre-set band-limited pre-distortion system model
Figure FDA00030743529600000314
And
Figure FDA00030743529600000315
and performing the model parameters based on the historical raw signal, the historical feedback signal, the baseband response of the filter, the total order of the filter, and the preset band-limited pre-distortion system model
Figure FDA00030743529600000316
Figure FDA00030743529600000317
And
Figure FDA00030743529600000318
through the preset band-limited pre-distortion system model, calculating the model parameter r of the preset band-limited pre-distortion system model 1l ，r 2l And r 3l The iteration value of (1).
5. The method of claim 4, wherein the model parameters based on the historical raw signal, the historical feedback signal, the baseband response of the filter, the total order of the filter, and the pre-set band-limited pre-distortion system model
Figure FDA0003074352960000041
And
Figure FDA0003074352960000042
through the preset band-limited pre-distortion system model, calculating the model parameter r of the preset band-limited pre-distortion system model 1l ，r 2l And r 3l Comprises:
based on the historical raw signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the model parameters of the preset band-limited pre-distortion system model
Figure FDA0003074352960000043
And
Figure FDA0003074352960000044
through the preset band-limited predistortion system model, and the least square method is adopted to calculate the model parameter r of the preset band-limited predistortion system model 1l ，r 2l And r 3l An iteration value of (d);
the model parameter r based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the preset band-limited pre-distortion system model 1l ，r 2l ，r 3l Through the preset band limit lossA true system model for calculating the model parameters of the pre-set band-limited pre-distortion system model
Figure FDA0003074352960000045
And
Figure FDA0003074352960000046
comprises:
based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the model parameter r of the preset band-limited pre-distortion system model 1l ，r 2l ，r 3l Calculating the model parameters of the preset band-limited predistortion system model by the preset band-limited predistortion system model and the least square method
Figure FDA0003074352960000047
And
Figure FDA0003074352960000048
the iteration value of (2).
6. A band-limited predistortion system, the band-limited predistortion system comprising: the device comprises a predistorter, a digital-to-analog conversion and up-conversion module, a power amplifier, a coupler, a filter, an analog-to-digital conversion and down-conversion module and a modeler; the predistorter, the digital-to-analog conversion and up-conversion module, the power amplifier, the coupler, the filter, the analog-to-digital conversion and down-conversion module and the modeler are sequentially connected; the modeler is connected with the predistorter;
the modeler is to: acquiring a historical original signal input into the digital-to-analog conversion and up-conversion module, a historical feedback signal output by the analog-to-digital conversion and down-conversion module, a baseband response of the filter and a total order of the filter, wherein the historical feedback signal is a signal output by the historical original signal after passing through the digital-to-analog conversion and up-conversion module, the power amplifier, the coupler, the filter and the analog-to-digital conversion and down-conversion module;
the modeler, further configured to: determining model parameters of a power amplifier model to be established based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and a preset band-limited pre-distortion system model;
the modeler, further configured to: establishing the power amplifier model based on the model parameters; determining a predistortion model corresponding to the predistorter based on the power amplifier model and the historical original signal;
the predistorter is used for carrying out predistortion processing on an original signal to be distorted by adopting the predistortion model and inputting a signal to be amplified after the predistortion processing to the power amplifier;
the power amplifier is used for amplifying the pre-distorted signal to be amplified output by the pre-distorter.
7. The system of claim 6, wherein the modeler is further configured to:
before determining model parameters of the power amplifier model to be established based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and a preset band-limited pre-distortion system model, synchronizing the historical original signal and the historical feedback signal to obtain the synchronized historical original signal and the synchronized historical feedback signal;
the modeler, further configured to:
and determining model parameters of the power amplifier model to be established based on the synchronized historical original signal, the synchronized historical feedback signal, the baseband response of the filter, the total order of the filter and the preset band-limited pre-distortion system model.
8. The system of claim 6, wherein the pre-set band-limited pre-distortion system model is represented by the following formula:
Figure FDA0003074352960000051
wherein, the
Figure FDA0003074352960000052
For feedback signals, w (P) is the baseband response of the filter, P is the total order of the filter, and L a Said L is b And said L c Respectively a preset memory depth parameter, K a ，K b And K c Respectively, a preset order, M b For a preset delay depth, M c The depth is a preset leading depth; the x (n-l) 1 P) as the l-th of the original signal x (n) 1 + p time-delayed signals, said x (n-l) 2 -p) is the l-th of the original signal x (n) 2 + p time-delayed signals, said x (n-l) 2 -m 2 -p) is the l-th of the original signal x (n) 2 +m 2 + p time-delayed signals, said x (n-l) 3 -p) is the l-th of the original signal x (n) 3 + p time-delayed signals, said x (n-l) 3 +m 3 -p) is the l-th of the original signal x (n) 3 -m 3 + p time-delayed signals, said r 1l ，r 2l ，r 3l ，
Figure FDA0003074352960000061
And
Figure FDA0003074352960000062
model parameters of the preset band-limited pre-distortion system model are set;
the power amplifier model to be established is as follows:
Figure FDA0003074352960000063
wherein, the
Figure FDA0003074352960000064
For a full band signal corresponding to an original signal output by the power amplifier, the x (n-l) 1 ) Is the l-th of the original signal x (n) 1 A time delay signal, said x (n-l) 2 ) Is the l-th of the original signal x (n) 2 A time delay signal, said x (n-l) 2 -m 2 ) Is the l-th of the original signal x (n) 2 +m 2 A time delay signal, said x (n-l) 3 ) Is the l-th of the original signal x (n) 3 A time delay signal, said x (n-l) 3 +m 3 ) Is the l-th of the original signal x (n) 3 -m 3 A time delayed signal.
9. The system of claim 8, wherein the modeler is specifically configured to:
obtaining model parameters of the preset band-limited predistortion system model
Figure FDA0003074352960000065
And
Figure FDA0003074352960000066
wherein the initial value is a preset value;
based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the model parameters of the preset band-limited pre-distortion system model
Figure FDA0003074352960000067
And
Figure FDA0003074352960000068
by said predetermined band-limited predistortion systemA system model for calculating the model parameter r of the pre-set band-limited pre-distortion system model 1l ，r 2l And r 3l The iteration value of (a);
based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the model parameter r of the preset band-limited pre-distortion system model 1l ，r 2l ，r 3l Calculating the model parameters of the preset band-limited predistortion system model through the preset band-limited predistortion system model
Figure FDA00030743529600000718
And
Figure FDA0003074352960000071
an iteration value of (d);
model parameter r of the preset band-limited predistortion system model 1l ，r 2l ，r 3l ，
Figure FDA0003074352960000072
And
Figure FDA0003074352960000073
when the iteration value of the preset band-limited pre-distortion system model reaches a preset output condition, the model parameter r of the preset band-limited pre-distortion system model is set 1l ，r 2l ，r 3l ，
Figure FDA0003074352960000074
And
Figure FDA0003074352960000075
as a model parameter of the power amplifier model to be built;
otherwise, model parameters of the preset band-limited predistortion system model are set
Figure FDA0003074352960000076
And
Figure FDA0003074352960000077
as a model parameter of the pre-set band-limited pre-distortion system model
Figure FDA0003074352960000078
And
Figure FDA0003074352960000079
and performing the model parameters based on the historical raw signal, the historical feedback signal, the baseband response of the filter, the total order of the filter, and the preset band-limited pre-distortion system model
Figure FDA00030743529600000710
Figure FDA00030743529600000711
And
Figure FDA00030743529600000712
through the preset band-limited pre-distortion system model, calculating the model parameter r of the preset band-limited pre-distortion system model 1l ，r 2l And r 3l The iteration value of (1).
10. The system of claim 9, wherein the modeler is specifically configured to:
based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the model parameters of the preset band-limited pre-distortion system model
Figure FDA00030743529600000713
And
Figure FDA00030743529600000714
by the preset ofA band-limited predistortion system model, and a least square method is adopted to calculate the model parameter r of the preset band-limited predistortion system model 1l ，r 2l And r 3l An iteration value of (d);
based on the historical original signal, the historical feedback signal, the baseband response of the filter, the total order of the filter and the model parameter r of the preset band-limited pre-distortion system model 1l ，r 2l ，r 3l Calculating the model parameters of the preset band-limited predistortion system model by the preset band-limited predistortion system model and adopting the least square method
Figure FDA00030743529600000715
And
Figure FDA00030743529600000716
the iteration value of (2).
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