CN112995079B

CN112995079B - Signal processing method and related equipment

Info

Publication number: CN112995079B
Application number: CN201911284414.0A
Authority: CN
Inventors: 杜帅乐; 吴燕鸣; 沈滔
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2022-03-11
Anticipated expiration: 2039-12-13
Also published as: CN112995079A

Abstract

A signal processing method includes: carrying out amplitude-phase conversion on the input IQ signal to obtain the envelope of the IQ signal; determining a first envelope tracking signal corresponding to the envelope of the IQ signal according to a preset shaping lookup table, and carrying out envelope tracking modulation according to the first envelope tracking signal; acquiring a second envelope tracking signal according to a first envelope tracking voltage obtained by envelope tracking modulation; determining a parameter value sequence of the calibration parameter according to the first envelope tracking signal and the second envelope tracking signal; adjusting the first envelope tracking signal according to the parameter value sequence; carrying out envelope tracking modulation according to the adjusted third envelope tracking signal; and inputting the second envelope tracking voltage obtained by envelope tracking modulation into the power amplifier, so that the error between the third envelope tracking voltage and the envelope tracking expected voltage is smaller, the linearity of the power amplifier can be improved, and the power consumption is reduced. The application also provides a related device capable of realizing the signal processing method.

Description

Signal processing method and related equipment

Technical Field

The present application relates to the field of communications technologies, and in particular, to a signal processing method and a related device.

Background

Envelope Tracking (ET) is a method for improving the linearity of a Power Amplifier (PA), which can make the supply voltage of the PA similar to the envelope of the output signal of the PA, thereby reducing the power consumption of the PA.

In practical applications, it is difficult for a device with an envelope tracking function, called an Envelope Tracking Modulator (ETM), to provide an ideal envelope tracking voltage. For example, the gain of an ETM is shown in fig. 1, with the gain on the vertical axis of fig. 1. The horizontal axis is frequency in megahertz (MHz). The practical gain of the ETM is close to 1 in the range of 0-40 MHz, and better linearity can be provided for the PA at the moment. In the range of more than 40MHz, for example, in the range of 80-100 MHz, the actual gain of the ETM will have a large deviation, and the envelope tracking voltage outputted by the ETM is shown in FIG. 2. When the deviation between the actual envelope tracking voltage of the ETM and the ideal envelope tracking voltage is large, it is difficult to improve the linearity of the PA.

Disclosure of Invention

In view of this, the present application provides a signal processing method, which makes the envelope tracking voltage output by the ETM more similar to the envelope of the IQ signal by adjusting the ETM input voltage.

A first aspect of the present application provides a signal processing method. In the method, an input IQ signal is subjected to amplitude-phase conversion to obtain an envelope of the IQ signal; determining a first envelope tracking signal corresponding to the envelope of the IQ signal according to a preset shaping lookup table, and carrying out envelope tracking modulation according to the first envelope tracking signal; acquiring a second envelope tracking signal according to a first envelope tracking voltage obtained by envelope tracking modulation; determining a parameter value sequence of the calibration parameter according to the first envelope tracking signal and the second envelope tracking signal; adjusting the first envelope tracking signal according to the parameter value sequence of the calibration parameter; carrying out envelope tracking modulation according to the adjusted third envelope tracking signal; and inputting a second envelope tracking voltage obtained by envelope tracking modulation into the power amplifier, so that the power amplifier processes the radio frequency signal according to the second envelope tracking voltage, and the mean square error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than that between the first envelope tracking voltage and the envelope tracking expected voltage. The preset shaping look-up table is used for storing the correspondence of the envelope and the envelope tracking signal,

in this embodiment, the second envelope tracking signal may reflect the envelope tracking voltage actually output by the ETM, and the first envelope tracking signal is used to represent the envelope tracking desired voltage output by the ideal voltage converter. The calibration parameter value sequence for reducing errors can be obtained through calculation according to the first envelope tracking signal and the second envelope tracking signal, the first envelope tracking signal is adjusted through the calibration parameter value sequence, envelope tracking modulation is carried out according to the adjusted envelope tracking signal (namely, the third envelope tracking signal), and the second envelope tracking voltage which is closer to the first envelope tracking signal can be obtained, so that the linearity of the PA can be improved, and the power consumption of the PA is reduced.

In one possible implementation, determining the sequence of calibration parameter values from the first envelope tracking signal and the second envelope tracking signal includes: determining a frequency response characteristic of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; determining a frequency response characteristic of the calibration unit according to the frequency response characteristic of the envelope tracking modulator; a sequence of parameter values for the calibration parameter is determined from the frequency response characteristic of the calibration unit. The sequence of parameter values of the calibration parameter may be obtained by inverse fourier transforming the frequency response characteristics of the calibration unit. The frequency response characteristic of the ETM is a set of parameter values that can reflect the gain and phase of the ETM at different frequency points. Because the product of the frequency response characteristic of the envelope tracking modulator and the frequency response characteristic of the calibration unit is a preset constant, the frequency response characteristic of the calibration unit is calculated according to the frequency response characteristic of the ETM, and then the parameter value sequence of the calibration parameter is determined, so that the gains of the calibration unit and the ETM to the first envelope tracking signal (namely the envelope tracking expected voltage) are close to or equal to the preset constant, the envelope tracking voltage output by the ETM is similar to the first envelope tracking signal, the linearity of the power amplifier can be improved, and the power consumption of the power amplifier can be reduced.

In another possible implementation, determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal includes: determining a desired input signal for the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; operating on the first envelope tracking signal and the desired input signal of the envelope tracking modulator using an adaptive algorithm; and when the error obtained by the operation is smaller than the preset error, determining the parameter value sequence corresponding to the error obtained by the operation as the parameter value sequence of the calibration parameter. Optionally, the adaptive algorithm is a least mean square error algorithm or a least square algorithm. According to the implementation, iterative processing can be performed on the first envelope tracking signal and the expected input signal of the envelope tracking modulator by using a self-adaptive algorithm, the error is continuously reduced in the iterative process, when the error is smaller than the preset error, the parameter value sequence corresponding to the error is determined to be the parameter value sequence of the calibration parameter, the first envelope tracking signal is corrected according to the parameter value sequence, and the envelope tracking voltage obtained by envelope tracking modulation according to the third envelope tracking signal is similar to or the same as the expected input signal, so that the envelope tracking voltage is closer to the expected envelope tracking voltage.

In another possible implementation, determining the sequence of parameter values of the calibration parameter from the first envelope tracking signal and the second envelope tracking signal includes: determining a desired input signal for the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; and processing the first envelope tracking signal and the expected input signal of the envelope tracking modulator by using a neural network algorithm to obtain a parameter value sequence of the calibration parameter. According to the implementation, the first envelope tracking signal and the expected input signal of the envelope tracking modulator can be processed by using a neural network algorithm, a parameter value sequence of a calibration parameter can be obtained, the parameter value sequence of the calibration parameter is used for representing the minimum loss degree from the first envelope tracking signal to the expected input signal, the first envelope tracking signal is corrected according to the parameter value sequence to obtain a third envelope tracking signal, and the third envelope tracking signal is similar or identical to the expected input signal, so that the envelope tracking voltage obtained by envelope tracking modulation according to the third envelope tracking signal is closer to the envelope tracking expected voltage, the linearity of the power amplifier can be improved, and the power consumption of the power amplifier can be reduced.

In a possible implementation form of the first aspect, the calibration parameter is a filter coefficient, an equalizer coefficient, a fitting coefficient of a spline function, or a fitting coefficient of a polynomial.

A second aspect of the present application provides a signal processing method. In the method, an input IQ signal is subjected to amplitude-phase conversion to obtain an envelope of the IQ signal; determining a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping lookup table, wherein the first envelope tracking signal is used for indicating an envelope tracking expected voltage; carrying out envelope tracking modulation according to the first envelope tracking signal; converting a first envelope tracking voltage obtained by envelope tracking modulation into a second envelope tracking signal; determining a parameter value sequence of the calibration parameter according to the first envelope tracking signal and the second envelope tracking signal; adjusting the envelope of the IQ signal according to the parameter value sequence of the calibration parameter; determining a third envelope tracking signal corresponding to the adjusted envelope according to a preset shaping look-up table; carrying out envelope tracking modulation according to the third envelope tracking signal; and inputting a second envelope tracking voltage obtained by envelope tracking modulation into the power amplifier, so that the power amplifier processes the radio frequency signal according to the second envelope tracking voltage, and the mean square error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than the mean square error between the first envelope tracking voltage and the envelope tracking expected voltage.

According to the implementation, the second envelope tracking signal can reflect the envelope tracking voltage actually output by the ETM, the first envelope tracking signal is used for representing the envelope tracking expected voltage, the calibration parameter value sequence can be determined according to the first envelope tracking signal and the second envelope tracking signal, the envelope of the IQ signal is adjusted by using the calibration parameter value sequence, envelope tracking modulation is carried out according to the envelope tracking signal (namely, the third envelope tracking signal) corresponding to the adjusted envelope, the envelope tracking voltage closer to the first envelope tracking signal can be obtained, the linearity of the PA can be improved, and therefore the power consumption of the PA is reduced.

In one possible implementation, determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal includes: determining a frequency response characteristic of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; determining a frequency response characteristic of the calibration unit according to the frequency response characteristic of the envelope tracking modulator; a sequence of parameter values for the calibration parameter is determined from the frequency response characteristic of the calibration unit. The sequence of parameter values of the calibration parameter may be obtained by inverse fourier transforming the frequency response characteristics of the calibration unit. The frequency response characteristic of the ETM is a set of parameter values that can reflect the gain and phase of the ETM at different frequency points. Because the product of the frequency response characteristic of the envelope tracking modulator and the frequency response characteristic of the calibration unit is a preset constant, the frequency response characteristic of the calibration unit is calculated according to the frequency response characteristic of the ETM, and then the parameter value sequence of the calibration parameter is determined, so that the gains of the calibration unit and the ETM to the first envelope tracking signal (namely the envelope tracking expected voltage) are close to or equal to the preset constant, the envelope tracking voltage output by the ETM is similar to the first envelope tracking signal, the linearity of the power amplifier can be improved, and the power consumption of the power amplifier can be reduced.

In another possible implementation, determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal includes: determining a desired input signal for the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; operating on the first envelope tracking signal and the desired input signal of the envelope tracking modulator using an adaptive algorithm; and when the error obtained by the operation is smaller than the preset error, determining the parameter value sequence corresponding to the error obtained by the operation as the parameter value sequence of the calibration parameter. Optionally, the adaptive algorithm is a least mean square error algorithm or a least square algorithm. According to the implementation, iterative processing can be performed on the first envelope tracking signal and the expected input signal of the envelope tracking modulator by using a self-adaptive algorithm, the error is continuously reduced in the iterative process, when the error is smaller than the preset error, the parameter value sequence corresponding to the error is determined to be the parameter value sequence of the calibration parameter, the first envelope tracking signal is corrected according to the parameter value sequence, and the envelope tracking voltage obtained by envelope tracking modulation according to the corrected third envelope tracking signal is more approximate to the envelope tracking expected voltage because the corrected third envelope tracking signal is similar to or identical to the expected input signal.

In another possible implementation, determining the sequence of parameter values of the calibration parameter from the first envelope tracking signal and the second envelope tracking signal includes: determining a desired input signal for the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; and processing the first envelope tracking signal and the expected input signal of the envelope tracking modulator by using a neural network algorithm to obtain a parameter value sequence of the calibration parameter.

According to the implementation, the first envelope tracking signal and the expected input signal of the envelope tracking modulator can be processed by using a neural network algorithm, a parameter value sequence of a calibration parameter can be obtained, the parameter value sequence of the calibration parameter is used for representing the conversion degree from the first envelope tracking signal to the expected input signal, the first envelope tracking signal is processed according to the parameter value sequence, and the envelope tracking voltage obtained by envelope tracking modulation according to the third envelope tracking signal is closer to the expected envelope tracking voltage because the third envelope tracking signal obtained by correction is similar to or identical to the expected input signal, so that the linearity of the power amplifier can be improved, and the power consumption of the power amplifier can be reduced.

In a possible implementation form of the second aspect, the calibration parameter is a filter coefficient, an equalizer coefficient, a fitting coefficient of a spline function, or a fitting coefficient of a polynomial.

A third aspect of the present application provides a signal processing method. In the method, an input IQ signal is subjected to amplitude-phase conversion to obtain an envelope of the IQ signal; determining a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping lookup table, wherein the first envelope tracking signal is used for indicating an envelope tracking expected voltage; carrying out envelope tracking modulation according to the first envelope tracking signal; inputting a first envelope tracking voltage obtained by envelope tracking modulation into a power amplifier; determining a second envelope tracking signal corresponding to the output power of the power amplifier according to the shaping lookup table; determining a parameter value sequence of the calibration parameter according to the first envelope tracking signal and the second envelope tracking signal; correcting the first envelope tracking signal according to the parameter value sequence of the calibration parameter to obtain a third envelope tracking signal; carrying out envelope tracking modulation according to the third envelope tracking signal; and inputting a second envelope tracking voltage obtained by envelope tracking modulation into the power amplifier, wherein the error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than the error between the first envelope tracking voltage and the envelope tracking expected voltage.

In this way, the second envelope tracking signal may be determined according to the output power of the power amplifier, and the second envelope tracking signal may reflect the envelope tracking voltage actually output by the ETM. The first envelope tracking signal is used for representing envelope tracking expected voltage, a calibration parameter value sequence for reducing errors can be obtained through operation according to the first envelope tracking signal and the second envelope tracking signal, the first envelope tracking signal is adjusted through the calibration parameter value sequence, envelope tracking modulation is carried out according to the adjusted envelope tracking signal (namely, the third envelope tracking signal), envelope tracking voltage which is closer to the envelope tracking expected voltage can be obtained, and therefore the linearity of the power amplifier can be improved, and the power consumption of the power amplifier is reduced.

In one possible implementation, determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal includes: determining a frequency response characteristic of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; determining the frequency response characteristic of the calibration unit according to the frequency response characteristic of the envelope tracking modulator, wherein the product of the frequency response characteristic of the envelope tracking modulator and the frequency response characteristic of the calibration unit is a preset constant; a sequence of parameter values for the calibration parameter is determined from the frequency response characteristic of the calibration unit.

In another possible implementation, determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal includes: determining a desired input signal for the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; operating on the first envelope tracking signal and the desired input signal of the envelope tracking modulator using an adaptive algorithm; and when the error obtained by the operation is smaller than the preset error, determining the parameter value sequence corresponding to the error obtained by the operation as the parameter value sequence of the calibration parameter. Optionally, the adaptive algorithm is a least mean square error algorithm or a least square algorithm. According to the implementation, iterative processing can be carried out on the first envelope tracking signal and the expected input signal of the envelope tracking modulator by using a self-adaptive algorithm, the error is continuously reduced in the iterative process, when the error is smaller than the preset error, a parameter value sequence corresponding to the error is determined, the first envelope tracking signal is corrected according to the parameter value sequence, and as the third envelope tracking signal obtained through correction is close to or the same as the expected input signal, the envelope tracking voltage obtained through envelope tracking modulation according to the third envelope tracking signal obtained through correction is closer to the expected envelope tracking voltage.

In another possible implementation, determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal includes: determining a desired input signal for the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; and processing the first envelope tracking signal and the expected input signal of the envelope tracking modulator by using a neural network algorithm to obtain a parameter value sequence of the calibration parameter. According to the implementation, the first envelope tracking signal and the expected input signal of the envelope tracking modulator can be processed by using a neural network algorithm, a parameter value sequence of a calibration parameter can be obtained, the parameter value sequence of the calibration parameter is used for representing the conversion degree from the first envelope tracking signal to the expected input signal, the first envelope tracking signal is corrected according to the parameter value sequence to obtain a third envelope tracking signal, and the third envelope tracking signal is similar or identical to the expected input signal, so that the envelope tracking voltage obtained by envelope tracking modulation according to the third envelope tracking signal is closer to the envelope tracking expected voltage, the linearity of the power amplifier can be improved, and the power consumption of the power amplifier can be reduced.

In a possible implementation form of the third aspect or the third aspect, the calibration parameter is a filter coefficient, an equalizer coefficient, a fitting coefficient of a spline function, or a fitting coefficient of a polynomial.

In another possible implementation manner, after a first envelope tracking voltage obtained by envelope tracking modulation is input to a power amplifier, a direct current offset error is determined according to a zero-frequency voltage of the second envelope tracking signal and a zero-frequency voltage of the first envelope tracking signal, and a direct current component adjustment amount is determined according to the direct current offset error, wherein the direct current component adjustment amount is an inverse number of the direct current offset error; and after the first envelope tracking signal is corrected according to the parameter value sequence of the calibration parameter to obtain a third envelope tracking signal, the direct-current component of the third envelope tracking signal is adjusted according to the direct-current component adjustment quantity. Therefore, the direct current loss of the envelope tracking signal in the transmission process can be reduced, and the distortion degree of the signal is reduced.

In another possible implementation manner, after a first envelope tracking voltage obtained by envelope tracking modulation is input to a power amplifier, a signal index of a radio frequency signal output by the power amplifier is obtained, wherein the signal index includes an adjacent channel power leakage ratio or an error vector amplitude; after the first envelope tracking signal is corrected according to the parameter value sequence of the calibration parameter to obtain a third envelope tracking signal, when the signal index is greater than or equal to a preset threshold value, the direct current component of the third envelope tracking signal is increased according to a preset increment. Therefore, the direct current loss of the envelope tracking signal in the transmission process can be reduced, and the distortion degree of the signal is reduced.

A fourth aspect provides a signal processing apparatus having a function of implementing the signal processing method of any one of the embodiments of the first aspect. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions.

A fifth aspect provides a signal processing apparatus having a function of implementing the signal processing method of any one of the embodiments of the second aspect. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions.

A sixth aspect provides a signal processing apparatus having a function of implementing the signal processing method of any one of the embodiments in the third aspect. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions.

A seventh aspect provides a terminal comprising a processor, a memory, a baseband unit, a radio frequency module, an antenna, and the signal processing apparatus according to any one of the above aspects, wherein the radio frequency module is connected to the baseband unit, the signal processing apparatus, and the antenna, respectively.

An eighth aspect provides a network device, which includes a processor, a memory, a baseband unit, a radio frequency module, an antenna, and the signal processing apparatus according to any one of the above aspects, where the radio frequency module is connected to the baseband unit, the signal processing apparatus, and the antenna, respectively.

A ninth aspect provides a computer storage medium having instructions stored thereon which, when executed on a computer, cause the computer to perform the method of the above aspect.

A tenth aspect provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of the above aspect.

Drawings

FIG. 1 is a diagram illustrating ETM gain in the prior art;

FIG. 2 is a schematic diagram of the envelope tracking voltage of a prior art ETM;

fig. 3 is a schematic structural diagram of an rf front end according to the present application;

FIG. 4 is a flow chart of a signal processing method of the present application;

FIG. 5 is another flow chart of a signal processing method of the present application;

FIG. 6 is another flow chart of the signal processing method of the present application;

fig. 7 is a block diagram of a signal processing apparatus according to the present application;

fig. 8 is another block diagram of the signal processing apparatus of the present application;

fig. 9 is another block diagram of the signal processing apparatus of the present application;

fig. 10 is a block diagram of a terminal in the present application;

fig. 11 is a block diagram of a network device according to the present application.

Detailed Description

The signal processing method of the present application can be applied to a signal processing apparatus having an envelope tracking function. The signal processing means may be a module of the terminal or a module of the network device. The signal processing means may be a radio frequency front end or a module or device in a radio frequency front end for performing an envelope tracking function.

The following describes a signal processing apparatus in the present application by taking an envelope tracking module in a radio frequency front end as an example:

referring to fig. 3, the radio frequency front end comprises a radio frequency module 31 and an envelope tracking module 32.

The radio frequency module 31 includes: a first delay adjusting unit 311, a digital predistortion unit 312, a digital-to-analog conversion unit 313, an up-conversion unit 314, a power amplifier 315, a duplexer 316, an antenna 317, and an adaptive iteration unit 318. The first delay adjusting unit 311 is connected to the digital predistortion unit 312, the digital predistortion unit 312 is connected to the digital-to-analog conversion unit 313, the digital-to-analog conversion unit 313 is connected to the up-conversion unit 314, the up-conversion unit 314 is connected to the power amplifier 315, and the adaptive iteration unit 318 is connected to the first delay adjusting unit 311, the digital predistortion unit 312, and the power amplifier 315.

The envelope tracking module 32 comprises: a second delay adjusting unit 321, a magnitude-phase converting unit 322, a shaping lookup table (shaping lookup table) unit 323, a calibrating unit 324, an envelope tracking modulator 325, and a processing unit 326. The second delay adjusting unit 321 is connected to the amplitude-phase converting unit 322, the amplitude-phase converting unit 322 is connected to the shaping lookup table unit 323, the shaping lookup table unit 323 is connected to the calibrating unit 324, the calibrating unit 324 is connected to the envelope tracking modulator 325, and the processing unit 326 is connected to the shaping lookup table unit 323, the calibrating unit 324, and the envelope tracking modulator 325, respectively.

The first delay adjusting unit 311 is connected to the second delay adjusting unit 321. The envelope tracking modulator 325 is connected to the power amplifier 315. The envelope tracking modulator 325 is used to provide an envelope tracking voltage to the power amplifier 315. The power amplifier 315 is used to process the radio frequency signal according to the envelope tracking voltage.

The first delay adjustment unit 311, the adaptive iteration unit 318, and the second delay adjustment unit 321 are not essential components, and may be configured according to actual needs. It should be noted that a coupler or a digital-to-analog conversion unit may be added to the circuit according to actual needs, for example, the input signal of the envelope tracking modulator 325 may be a digital signal or an analog signal. And the output of the shaping look-up table unit 323 is a digital signal. In practical applications, a digital-to-analog conversion unit may be provided after the calibration unit 324, and the digital-to-analog conversion unit converts the digital signal into an analog signal, so that the input signal of the envelope tracking modulator 325 can be an analog signal.

In the rf front end shown in fig. 3, when an in-phase quadrature (IQ) signal is processed by the first delay adjusting unit 311, the digital predistortion unit 312, the digital-to-analog converting unit 313 and the frequency up-converting unit 314 to form an rf signal input to the power amplifier 315, the adaptive iteration unit 318 may perform adaptive iteration processing according to the IQ signal output by the first delay adjusting unit 311 and the rf signal output by the power amplifier 315.

When the IQ signal passes through the first delay adjusting unit 311, the second delay adjusting unit 321, the amplitude-phase converting unit 322, the shaping lookup table (shaping lookup table) unit 323, the calibrating unit 324, and the envelope tracking modulator 325, the processing unit 326 may set the calibration parameter of the calibrating unit 324 according to the envelope tracking signal output by the shaping lookup table unit 323 and the envelope tracking voltage output by the envelope tracking modulator 325, so that the envelope tracking voltage output by the envelope tracking modulator 325 can be similar to the desired envelope tracking voltage, and the power amplifier 315 can keep the output power unchanged according to such envelope tracking voltage under the condition of saving power consumption.

The processing unit 326 may be an ARM processor, which is collectively referred to as Advanced RISC Machines. RISC refers to a reduced instruction set computer (reduced instruction set computer), and the processing unit 326 may also be a Digital Signal Processor (DSP), a Central Processing Unit (CPU), a field-programmable gate array (FPGA), or other programmable logic devices. The calibration unit 324 may be an FPGA or other programmable logic device.

It should be noted that in another envelope tracking module, the calibration unit 324 may also be disposed not after the shaping lookup table unit 323 but between the amplitude-to-phase conversion unit 322 and the shaping lookup table unit 323.

Based on the signal processing apparatus shown in fig. 3, the present application provides a signal processing method capable of adjusting the ETM input voltage and reducing the gain deviation of the ETM, so that the envelope tracking voltage output by the ETM is more similar to the desired envelope tracking voltage.

Referring to fig. 4, an embodiment of a signal processing method provided by the present application includes:

step 401, performing amplitude-phase conversion on the input IQ signal to obtain an envelope of the IQ signal. The envelope is the amplitude of the IQ signal in the time domain.

Step 402, determining a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping look-up table.

The preset shaping lookup table is used for storing the corresponding relation between the output power of the power amplifier and the envelope tracking signal. The envelope of the IQ signal corresponds one-to-one to the output power of the power amplifier. The envelope tracking signal (i.e. the first envelope tracking signal) corresponding to the envelope of the IQ signal can thus be determined from the preset shaping look-up table. The envelope tracking signal obtained from the preset shaping look-up table is used to represent an envelope tracking desired voltage, which is an envelope tracking voltage output using an ideal voltage converter. Generally, the trend of the envelope tracking expected voltage is consistent with the trend of the envelope. In the envelope, when the amplitude of a certain moment is large, the voltage corresponding to the moment is high; when the amplitude at a certain moment is small, the voltage corresponding to the moment is low.

And 403, performing envelope tracking modulation according to the first envelope tracking signal.

And step 404, acquiring a second envelope tracking signal according to the first envelope tracking voltage obtained by envelope tracking modulation.

Specifically, the first envelope tracking voltage is subjected to analog-to-digital conversion to obtain a second envelope tracking signal.

Step 405, determining a parameter value sequence of the calibration parameter according to the first envelope tracking signal and the second envelope tracking signal.

The calibration parameters may be filter coefficients, equalizer coefficients, fitting coefficients of a spline function, or fitting coefficients of a polynomial.

Step 406, the first envelope tracking signal is adjusted according to the parameter value sequence of the calibration parameter.

And step 407, performing envelope tracking modulation according to the adjusted third envelope tracking signal.

And step 408, inputting the second envelope tracking voltage obtained by envelope tracking modulation into the power amplifier, so that the power amplifier processes the radio frequency signal according to the second envelope tracking voltage, and the error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than the error between the first envelope tracking voltage and the envelope tracking expected voltage.

Since the envelope tracking voltage is a curve, sampling points can be selected from the curve, and then the mean square error of the two curve sampling point sequences is used as the error of the two envelope tracking voltages. The ith sample point can be noted as (x)_i,y_i),x_iRepresenting the frequency, y, of the ith sample point_iRepresenting the magnitude of the ith sample point. Specifically, the error of the second envelope tracking voltage from the envelope tracking desired voltage may be a mean square error of a sequence of sampling points in the second envelope tracking voltage from the envelope tracking desired voltage. Besides the mean square error, the error of the two curves can be expressed in other ways, and is not limited herein.

In this embodiment, a calibration parameter value sequence for reducing an error may be obtained by operation according to the first envelope tracking signal and the second envelope tracking signal, the first envelope tracking signal is adjusted by using the calibration parameter value sequence, and envelope tracking modulation is performed according to an adjusted envelope tracking signal (i.e., a third envelope tracking signal), so that an envelope tracking voltage (i.e., a second envelope tracking voltage) closer to the first envelope tracking signal can be obtained, which can improve linearity of the power amplifier, thereby reducing power consumption of the power amplifier.

In an alternative embodiment, determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal comprises: determining a frequency response characteristic of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; determining the frequency response characteristic of the calibration unit according to the frequency response characteristic of the envelope tracking modulator, wherein the product of the frequency response characteristic of the envelope tracking modulator and the frequency response characteristic of the calibration unit is a preset constant; a sequence of parameter values for the calibration parameter is determined from the frequency response characteristic of the calibration unit.

In this embodiment, let the frequency response characteristic of ETM be denoted as h, which is a sequence of parameter values representing the gain and phase of ETM at different frequencies. The frequency response characteristic of the calibration unit is denoted h ', h' is a sequence of parameter values representing the gain and phase of the calibration unit at different frequencies. The sequence of parameter values for the calibration parameter is denoted w.

h and h' satisfy the following formula: h ═ C/h. C is a preset constant, and the value of C may be 1 or a constant greater than 0.

h' and w satisfy the following formula: w is IFFT (h'). IFFT () is an inverse fourier transform function.

Specifically, one or more envelopes input within a period of time can be acquired, and then the frequency response characteristic of the envelope tracking modulator is calculated according to the first envelope tracking signal and the second envelope tracking signal corresponding to the one or more envelopes, so as to determine the parameter value sequence of the calibration parameter. Therefore, gains of the calibration unit and the ETM to the IQ signals are close to or equal to a preset constant, so that the second envelope tracking voltage output by the ETM is similar to the first envelope tracking signal, the linearity of the power amplifier can be improved, and the power consumption of the power amplifier can be reduced.

In another alternative embodiment, determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal comprises: determining a desired input signal for the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; operating on the first envelope tracking signal and the desired input signal of the envelope tracking modulator using an adaptive algorithm; and when the error obtained by the operation is smaller than the preset error, determining the parameter value sequence corresponding to the error obtained by the operation as the parameter value sequence of the calibration parameter.

In this embodiment, the first envelope tracking signal is denoted as x, and the second envelope tracking signal is denoted as x_eThe desired input signal of the envelope tracking modulator is denoted d. x, x_eAnd d satisfies the following formula: d ═ x- (x)_e-x)。x_eX represents the difference of the envelope tracking voltage of the actual output of the ETM and the envelope tracking desired voltage. As can be seen from the equation, the desired input signal is the envelope tracking signal compensated for ETM gain deviations.

Optionally, the adaptive algorithm is a Least Mean Square (LMS) algorithm or a Least Square (LS) algorithm.

In one example, when the adaptive algorithm is the LMS algorithm, the sequence of initial values w of the parameters of the calibration parameters, the first envelope tracking signal x and the desired input signal d of the envelope tracking modulator satisfy the following equation:

y(k)＝w^T(k)x(k)；

e(k)＝d(k)-y(k)；

w(k+1)＝w(k)+ue(k)x(k)；

x is the input signal of the calibration unit and y represents the output signal of the calibration unit. k represents the number of iterations, x (k) represents a signal obtained by updating x for the kth time, y (k) represents a signal obtained by updating y for the kth time, d (k) represents a signal obtained by updating d for the kth time, and w (k) represents a parameter value sequence of the calibration parameter obtained by updating w for the kth time. w is preset according to practical experience. u denotes a step, the value of which can be set according to practical experience.

Iteration is performed according to the LMS algorithm, and e (k) can be gradually reduced. When e (k) is smaller than the preset error, determining a parameter value sequence of w (k) corresponding to e (k) as the calibration parameter. For example, w (k) may be a filter coefficient, an equalizer coefficient, a fitting coefficient of a spline function, or a fitting coefficient of a polynomial.

After the calibration unit is set according to the parameter value sequence, the calibration unit corrects the first envelope tracking signal according to the parameter value sequence, and since the third envelope tracking signal obtained by correction is similar to or the same as the expected input signal, the envelope tracking voltage obtained by envelope tracking modulation according to the third envelope tracking signal is closer to the expected envelope tracking voltage, so that the linearity of the power amplifier can be improved, and the power consumption of the power amplifier can be reduced.

In another example, for an input envelope, its corresponding first and second envelope tracking signals may be obtained, and the desired input signal corresponding to the envelope sampling point at each time instant may be determined.

The ith sampling point in the first envelope tracking signal is marked as x_iETM according to x_iThe output signal is

x_iThe corresponding desired input signal is denoted d_iThen x_i、

And d_iThe following formula is satisfied:

when the adaptive algorithm is the LS algorithm, x_iThe signal of the corresponding jth frequency point can be recorded as X_ij，X_ijAnd d_iThe following formula is satisfied:

β_jand the value of the calibration coefficient of the j frequency point, i is a positive integer smaller than m, m is the total number of sampling points in the first time period, and n is the number of all parameter values included in the parameter value sequence of one calibration parameter.

Mixing X_ijThe matrix formed is denoted X and beta₁,...,β_jThe formed vector is denoted as beta, and y is₁,...,y_iThe resulting vector is denoted as y.If X is^TX is non-singular, then β satisfies the following equation:

representing an unbiased estimate of beta.

This allows the calculation of β corresponding to the minimum error, for example as a filter coefficient, an equalizer coefficient, a fitting coefficient of a spline function or a fitting coefficient of a polynomial. The first envelope tracking signal is corrected according to the beta, and the corrected third envelope tracking signal is similar to or the same as the expected input signal, so that the envelope tracking voltage obtained by envelope tracking modulation according to the third envelope tracking signal is closer to the expected envelope tracking voltage, the linearity of the power amplifier can be improved, and the power consumption of the power amplifier can be reduced.

In another embodiment, determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal comprises: determining a desired input signal for the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; and processing the first envelope tracking signal and the expected input signal of the envelope tracking modulator by using a neural network algorithm to obtain a parameter value sequence of the calibration parameter.

The sequence of parameter values of the calibration parameter is used to represent a minimum degree of loss from the first envelope tracking signal to the desired input signal. And modifying the first envelope tracking signal according to the parameter value sequence to obtain a third envelope tracking signal, wherein the third envelope tracking signal is similar to or the same as the expected input signal, so that the envelope tracking voltage obtained by envelope tracking modulation according to the third envelope tracking signal is closer to the expected envelope tracking voltage, thereby improving the linearity of the power amplifier and reducing the power consumption of the power amplifier.

According to the signal processing method, when the gain of the ETM is changed due to temperature change or ETM aging and the like, the parameter value sequence of the calibration parameter can be obtained again according to the method to adjust the first envelope tracking signal, and the envelope tracking voltage close to or equal to the expected envelope voltage can be obtained according to the adjusted envelope tracking signal, so that the influence of the temperature change or the ETM aging on the power consumption of the power amplifier can be reduced.

In addition to adjusting the envelope tracking signal according to the sequence of parameter values of the calibration parameter, the present application may also adjust the envelope according to the sequence of parameter values of the calibration parameter, which may also reduce the gain offset of the ETM. Referring to fig. 5, another embodiment of the signal processing method provided in the present application includes:

step 501, performing amplitude-phase conversion on the input IQ signal to obtain an envelope of the IQ signal.

Step 502, determining a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping look-up table.

The first envelope tracking signal is indicative of an envelope tracking desired voltage.

And step 503, performing envelope tracking modulation according to the first envelope tracking signal.

Step 504, converting the first envelope tracking voltage obtained by envelope tracking modulation into a second envelope tracking signal.

And 505, determining a parameter value sequence of the calibration parameter according to the first envelope tracking signal and the second envelope tracking signal.

Step 506, adjusting the envelope of the IQ signal according to the parameter value sequence of the calibration parameter.

Step 507, determining a third envelope tracking signal corresponding to the adjusted envelope according to a preset forming lookup table.

And step 508, performing envelope tracking modulation according to the third envelope tracking signal.

Step 509, inputting the second envelope tracking voltage obtained by envelope tracking modulation to the power amplifier, so that the power amplifier processes the radio frequency signal according to the second envelope tracking voltage. The error of the second envelope tracking voltage from the envelope tracking desired voltage is less than the error of the first envelope tracking voltage from the envelope tracking desired voltage.

In this embodiment, steps 501 to 505 are similar to steps 401 to 405, and refer to corresponding contents in the embodiment or the alternative embodiment shown in fig. 4. In

steps

506 and 507, the envelope of the IQ signal may be adjusted according to the parameter value sequence of the calibration parameter, an envelope tracking voltage corresponding to the adjusted envelope is searched, and then envelope tracking modulation is performed according to the envelope tracking voltage, so that the gain deviation of the ETM can also be reduced, thereby improving the linearity of the PA and reducing the power consumption of the PA.

In addition to converting the first envelope tracking voltage obtained by envelope tracking modulation into the second envelope tracking signal, the present application may also determine the second envelope tracking signal used for calculating the parameter value sequence of the calibration parameter according to the output power of the power amplifier. Referring to fig. 6, another embodiment of the signal processing method provided in the present application includes:

step 601, performing amplitude-phase conversion on the input IQ signal to obtain an envelope of the IQ signal.

Step 602, determining a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping look-up table.

And 603, carrying out envelope tracking modulation according to the first envelope tracking signal.

And step 604, inputting the first envelope tracking voltage obtained by envelope tracking modulation into the power amplifier.

Step 605, determining a second envelope tracking signal corresponding to the output power of the power amplifier according to a preset forming lookup table.

Step 606, determining a parameter value sequence of the calibration parameter according to the first envelope tracking signal and the second envelope tracking signal.

Step 607, the first envelope tracking signal is corrected according to the parameter value sequence of the calibration parameter, and a third envelope tracking signal is obtained.

And 608, performing envelope tracking modulation according to the third envelope tracking signal.

Step 609, inputting the second envelope tracking voltage obtained by envelope tracking modulation into the power amplifier, wherein the error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than the error between the first envelope tracking voltage and the envelope tracking expected voltage.

In this embodiment, steps 601 to 603 are similar to steps 401 to 403, and steps 606 to 609 are similar to steps 405 to 408, and the specific contents can refer to the corresponding contents in the embodiment or the alternative embodiment shown in fig. 4.

In steps 604 to 605, after the first envelope tracking voltage obtained by envelope tracking modulation is input to the power amplifier, the output power of the power amplifier is obtained, and a second envelope tracking signal corresponding to the output power of the power amplifier is determined according to the shaping lookup table. This second envelope tracking signal may reflect the actual supply voltage of the power amplifier, which may be considered the envelope tracking voltage of the actual output of the ETM. The calibration parameter value sequence for reducing errors can be obtained through operation according to the first envelope tracking signal and the second envelope tracking signal, the first envelope tracking signal is adjusted through the calibration parameter value sequence, envelope tracking modulation is carried out according to the adjusted envelope tracking signal (namely, the third envelope tracking signal), envelope tracking voltage which is closer to the first envelope tracking signal can be obtained, and therefore the linearity of the power amplifier can be improved, and the power consumption of the power amplifier is reduced.

In an optional embodiment, after a first envelope tracking voltage obtained by envelope tracking modulation is input to a power amplifier, a direct current offset error is determined according to a zero-frequency voltage of a second envelope tracking signal and a zero-frequency voltage of the first envelope tracking signal, and a direct current component adjustment quantity is determined according to the direct current offset error, wherein the direct current component adjustment quantity is an inverse number of the direct current offset error; and after the first envelope tracking signal is corrected according to the parameter value sequence of the calibration parameter to obtain a third envelope tracking signal, the direct-current component of the third envelope tracking signal is adjusted according to the direct-current component adjustment quantity.

In this embodiment, the zero-frequency voltage of the second envelope tracking signal represents an actual zero-frequency voltage output by the ETM, the zero-frequency voltage of the first envelope tracking signal represents an expected zero-frequency voltage, a result obtained by subtracting the zero-frequency voltage of the first envelope tracking signal from the zero-frequency voltage of the second envelope tracking signal is a dc offset error, and the dc offset error represents a difference between an actual output dc component of the ETM and an expected output dc component. Then, the dc component adjustment amount is determined according to the dc offset error, for example, if the dc offset error is 0.1 volt, the dc component adjustment amount may be determined to be-0.1 volt. Therefore, the direct current loss of the envelope tracking signal in the transmission process can be reduced, the distortion degree of the signal is reduced, and the accuracy of the signal is improved.

In another optional embodiment, after a first envelope tracking voltage obtained by envelope tracking modulation is input to a power amplifier, a signal index of a radio frequency signal output by the power amplifier is obtained, wherein the signal index comprises an adjacent channel power leakage ratio or an error vector amplitude; after the first envelope tracking signal is corrected according to the parameter value sequence of the calibration parameter to obtain a third envelope tracking signal, when the signal index is greater than or equal to a preset threshold value, the direct current component of the third envelope tracking signal is increased according to a preset increment.

In this embodiment, when the adjacent channel power leakage ratio is greater than or equal to the preset power leakage ratio, it indicates that the signal quality of the radio frequency signal output by the power amplifier is poor. And when the error vector amplitude ratio is greater than or equal to the preset error vector amplitude, indicating that the signal quality of the radio-frequency signal output by the power amplifier is poor. Increasing the dc component of the third envelope tracking signal can increase the input voltage of the power amplifier, thereby improving the quality of the signal output by the power amplifier and reducing the degree of signal distortion. The value of the increment may be preset based on practical experience.

The signal processing method in the present application is described above, and the signal processing apparatus in the present application is described below. Referring to fig. 7, the present application provides a signal processing apparatus 700 capable of implementing the signal processing method in the embodiment shown in fig. 4. In one embodiment, the signal processing apparatus 700 includes:

an amplitude-phase conversion unit 701, configured to perform amplitude-phase conversion on an input in-phase quadrature IQ signal to obtain an envelope of the IQ signal;

a shaping lookup table unit 702, configured to determine a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping lookup table, where the preset shaping lookup table is used to store a corresponding relationship between the envelope and the envelope tracking signal, and the first envelope tracking signal is used to represent an envelope tracking expected voltage;

an envelope tracking modulator 703 for performing envelope tracking modulation according to the first envelope tracking signal;

a processing unit 704, configured to obtain a second envelope tracking signal according to the first envelope tracking voltage obtained by envelope tracking modulation;

a processing unit 704, further configured to determine a parameter value sequence of the calibration parameter according to the first envelope tracking signal and the second envelope tracking signal;

a calibration unit 705, configured to adjust the first envelope tracking signal according to a parameter value sequence of a calibration parameter;

the envelope tracking modulator 703 is further configured to perform envelope tracking modulation according to the adjusted third envelope tracking signal; and inputting a second envelope tracking voltage obtained by envelope tracking modulation into the power amplifier, so that the power amplifier processes the radio frequency signal according to the second envelope tracking voltage, and the mean square error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than that between the first envelope tracking voltage and the envelope tracking expected voltage.

In this embodiment, before configuring the parameter value sequence of the calibration parameter, the calibration unit 705 does not adjust the first envelope tracking signal output by the shaping lookup table unit. The processing unit 704 may be an ARM processor, DSP, CPU, or FPGA. The calibration unit 705 may be an FPGA or other logic unit.

In an alternative embodiment of the method of the invention,

a processing unit 704, specifically configured to determine a frequency response characteristic of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; determining the frequency response characteristic of the calibration unit according to the frequency response characteristic of the envelope tracking modulator, wherein the product of the frequency response characteristic of the envelope tracking modulator and the frequency response characteristic of the calibration unit is a preset constant;

a sequence of parameter values for the calibration parameter is determined from the frequency response characteristic of the calibration unit.

In a further alternative embodiment of the method,

a processing unit 704, in particular for determining a desired input signal of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; operating on the first envelope tracking signal and the desired input signal of the envelope tracking modulator using an adaptive algorithm; and when the error obtained by the operation is smaller than the preset error, determining the parameter value sequence corresponding to the error obtained by the operation as the parameter value sequence of the calibration parameter.

Optionally, the adaptive algorithm is a least mean square error algorithm or a least square algorithm.

In a further alternative embodiment of the method,

a processing unit 704, in particular for determining a desired input signal of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; and processing the first envelope tracking signal and the expected input signal of the envelope tracking modulator by using a neural network algorithm to obtain a parameter value sequence of the calibration parameter.

In the embodiment shown in fig. 7 or an alternative embodiment, the calibration parameters are filter coefficients, equalizer coefficients, fitting coefficients of a spline function or fitting coefficients of a polynomial. For example, the calibration parameters are filter coefficients, and the calibration unit 705 is a Finite Impulse Response (FIR) filter implemented by an FPGA. Alternatively, the calibration parameter is an equalizer coefficient, and the calibration unit 705 is an equalizer implemented by an FPGA. Alternatively, the calibration parameter is a fitting coefficient of a spline function, and the calibration unit 705 is a spline lookup table unit implemented by an FPGA. Alternatively, the calibration parameter is a fitting coefficient of a polynomial, and the calibration unit 705 is a polynomial unit implemented by an FPGA.

Referring to fig. 8, the present application provides a signal processing apparatus 800 capable of implementing the signal processing method in the embodiment shown in fig. 5. In one embodiment, the signal processing apparatus 800 includes:

an amplitude-phase conversion unit 801, configured to perform amplitude-phase conversion on the input IQ signal to obtain an envelope of the IQ signal;

a shaping lookup table unit 802, configured to determine a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping lookup table, where the first envelope tracking signal is used to indicate an envelope tracking expected voltage;

an envelope tracking modulator 803 for performing envelope tracking modulation based on the first envelope tracking signal;

the processing unit 804 is configured to convert the first envelope tracking voltage obtained by envelope tracking modulation into a second envelope tracking signal;

the processing unit 804 is further configured to determine a parameter value sequence of the calibration parameter according to the first envelope tracking signal and the second envelope tracking signal;

a calibration unit 805, configured to adjust an envelope of the IQ signal according to a parameter value sequence of the calibration parameter;

a shaping look-up table unit 802, further configured to determine a third envelope tracking signal corresponding to the adjusted envelope according to a preset shaping look-up table;

an envelope tracking modulator 803, further configured to perform envelope tracking modulation according to the third envelope tracking signal; and inputting the second envelope tracking voltage obtained by envelope tracking modulation into the power amplifier, so that the power amplifier processes the input radio-frequency signal according to the second envelope tracking voltage, and the error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than the error between the first envelope tracking voltage and the envelope tracking expected voltage.

In this embodiment, the processing unit 804 may be an ARM processor, a DSP, a CPU, or an FPGA. The calibration unit 805 may be an FPGA or other logic unit.

In an alternative embodiment of the method of the invention,

a processing unit 804, specifically configured to determine a frequency response characteristic of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; determining the frequency response characteristic of the calibration unit according to the frequency response characteristic of the envelope tracking modulator, wherein the product of the frequency response characteristic of the envelope tracking modulator and the frequency response characteristic of the calibration unit is a preset constant; a sequence of parameter values for the calibration parameter is determined from the frequency response characteristic of the calibration unit.

In a further alternative embodiment of the method,

a processing unit 804, specifically configured to determine a desired input signal of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; operating on the first envelope tracking signal and the desired input signal of the envelope tracking modulator using an adaptive algorithm; and when the error obtained by the operation is smaller than the preset error, determining the parameter value sequence corresponding to the error obtained by the operation as the parameter value sequence of the calibration parameter.

In a further alternative embodiment of the method,

a processing unit, in particular for determining a desired input signal of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; and processing the first envelope tracking signal and the expected input signal of the envelope tracking modulator by using a neural network algorithm to obtain a parameter value sequence of the calibration parameter.

In the embodiment shown in fig. 8 or an alternative embodiment, the calibration parameters are filter coefficients, equalizer coefficients, fitting coefficients of a spline function or fitting coefficients of a polynomial. For example, the calibration parameters are filter coefficients, and the calibration unit 805 is an FIR filter implemented by an FPGA. Alternatively, the calibration parameters are equalizer coefficients and the calibration unit 805 is an equalizer implemented by an FPGA. Alternatively, the calibration parameter is a fitting coefficient of a spline function, and the calibration unit 805 is a spline lookup table unit implemented by an FPGA. Alternatively, the calibration parameters are fitting coefficients of a polynomial, and the calibration unit 805 is a polynomial unit implemented by an FPGA.

Referring to fig. 9, the present application provides a signal processing apparatus 900 capable of implementing the signal processing method in the embodiment shown in fig. 6. In one embodiment, the signal processing apparatus 900 includes:

an amplitude-phase conversion unit 901, configured to perform amplitude-phase conversion on the input IQ signal to obtain an envelope of the IQ signal;

a shaping lookup table unit 902, configured to determine, according to a preset shaping lookup table, a first envelope tracking signal corresponding to an envelope of the IQ signal, where the first envelope tracking signal is used to indicate an envelope tracking expected voltage;

an envelope tracking modulator 903, configured to perform envelope tracking modulation according to the first envelope tracking signal output by the shaping lookup table unit 902; inputting a first envelope tracking voltage obtained by envelope tracking modulation into a power amplifier;

a processing unit 904, configured to determine a second envelope tracking signal corresponding to the output power of the power amplifier according to the shaping lookup table obtained from the shaping lookup table unit 902;

a processing unit 904, further configured to determine a sequence of parameter values of the calibration parameter from the first envelope tracking signal and the second envelope tracking signal;

a calibration unit 905, configured to correct the first envelope tracking signal according to the parameter value sequence of the calibration parameter output by the processing unit 904, to obtain a third envelope tracking signal;

the envelope tracking modulator 903 is further configured to perform envelope tracking modulation according to the third envelope tracking signal output by the calibration unit 905; and inputting a second envelope tracking voltage obtained by envelope tracking modulation into the power amplifier, wherein the error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than the error between the first envelope tracking voltage and the envelope tracking expected voltage.

In this embodiment, before configuring the parameter value sequence of the calibration parameter, the calibration unit 905 does not adjust the first envelope tracking signal output by the shaping lookup table unit.

The processing unit 904 is connected to the shaping lookup table unit 902 and the power amplifier, respectively, and may obtain the shaping lookup table from the shaping lookup table 902, and determine the second envelope tracking signal corresponding to the output power of the power amplifier according to the shaping lookup table. The processing unit 904 may be an ARM processor, DSP, CPU, or FPGA. The calibration unit 905 may be an FPGA or other logic unit.

In an alternative embodiment of the method of the invention,

a processing unit 904, specifically configured to determine a frequency response characteristic of the envelope tracking modulator 903 according to the first envelope tracking signal and the second envelope tracking signal; determining the frequency response characteristic of the calibration unit 905 according to the frequency response characteristic of the envelope tracking modulator 903, wherein the product of the frequency response characteristic of the envelope tracking modulator 903 and the frequency response characteristic of the calibration unit 905 is a preset constant;

the sequence of parameter values of the calibration parameter is determined from the frequency response characteristics of the calibration unit 905.

In a further alternative embodiment of the method,

a processing unit 904, in particular for determining a desired input signal of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; the first envelope tracking signal and the desired input signal of the envelope tracking modulator 903 are operated on using an adaptive algorithm; and when the error obtained by the operation is smaller than the preset error, determining the parameter value sequence corresponding to the error obtained by the operation as the parameter value sequence of the calibration parameter.

In a further alternative embodiment of the method,

a processing unit 904, in particular for determining a desired input signal of the envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; the first envelope tracking signal and the desired input signal of the envelope tracking modulator 903 are processed using a neural network algorithm to obtain a sequence of parameter values for the calibration parameters.

In the embodiment shown in fig. 9 or an alternative embodiment, the calibration parameters are filter coefficients, equalizer coefficients, fitting coefficients of a spline function or fitting coefficients of a polynomial. For example, the calibration parameters are filter coefficients, and the calibration unit 905 is an FIR filter implemented by an FPGA. Alternatively, the calibration parameter is an equalizer coefficient, and the calibration unit 905 is an equalizer implemented by an FPGA. Alternatively, the calibration parameter is a fitting coefficient of a spline function, and the calibration unit 905 is a spline lookup table unit implemented by an FPGA. Alternatively, the calibration parameter is a fitting coefficient of a polynomial, and the calibration unit 905 is a polynomial unit implemented by an FPGA.

In another alternative embodiment, the processing unit 904 is connected to a power amplifier;

the processing unit 904 is further configured to determine a dc offset error according to the zero-frequency voltage of the second envelope tracking signal and the zero-frequency voltage of the first envelope tracking signal; determining a direct current component adjustment quantity according to the direct current offset error, wherein the direct current component adjustment quantity is the opposite number of the direct current offset error;

the signal processing apparatus 900 further includes:

and the direct current offset unit is configured to, after the calibration unit 905 corrects the first envelope tracking signal according to the parameter value sequence of the calibration parameter to obtain a third envelope tracking signal, adjust a direct current component of the third envelope tracking signal according to the direct current component adjustment amount.

the processing unit 904 is further configured to obtain a signal indicator of the radio frequency signal output by the power amplifier, where the signal indicator includes an adjacent channel power leakage ratio or an error vector magnitude;

the signal processing apparatus 900 further includes:

and the direct current offset unit is used for increasing the direct current component of the third envelope tracking signal according to a preset increment when the signal index is greater than or equal to a preset threshold.

Referring to FIG. 10, one embodiment of a terminal 1000 provided by the present application includes: the processor 1001, the memory 1002, the baseband unit 1003, the radio frequency module 1004, the antenna 1006 and the signal processing device 1005, wherein the processor 1001, the memory 1002 and the baseband unit 1003 are connected through a bus 1007, and the radio frequency module 1004 is connected with the baseband unit 1003, the signal processing device 1005 and the antenna 1006 respectively.

The number of the processor 1001, the memory 1002, and the antenna 1006 may be one or more. The processor 1001 may be a CPU, DSP, ARM processor, FPGA, or the like. The memory may be a Flash memory or a Static Random Access Memory (SRAM).

The signal processing apparatus 1005 may be any signal processing apparatus in the embodiments shown in fig. 7 to 9, and may implement the signal processing method in the embodiments shown in fig. 4 to 6.

Referring to fig. 11, one embodiment of a network device 1100 provided by the present application includes: the wireless communication device comprises a processor 1101, a memory 1102, a baseband unit 1103, a radio frequency module 1104, an antenna 1106 and a signal processing device 1105, wherein the processor 1101, the memory 1102 and the baseband unit 1103 are connected through a bus 1107, and the radio frequency module 1104 is respectively connected with the baseband unit 1103, the signal processing device 1105 and the antenna 1106.

The number of the processor 1101, the memory 1102 and the antenna 1106 may be one or more. The processor 1101 may be a CPU, DSP, ARM processor, FPGA, or the like. The memory may be a Flash memory or an SRAM.

The signal processing apparatus 1105 may be any one of the signal processing apparatuses in the embodiments shown in fig. 6 to 8, and may implement the signal processing method described in any one of the embodiments shown in fig. 4 to 6.

The present application provides a computer-readable storage medium comprising instructions which, when run on a computer, cause the computer to perform a method as described in any one of the above embodiments.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, 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 on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can store or a data storage device, such as a server, a data center, etc., that is integrated with one or more 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.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. A signal processing method, comprising:

carrying out amplitude-phase conversion on the input in-phase quadrature IQ signal to obtain the envelope of the IQ signal;

determining a first envelope tracking signal corresponding to the envelope of the IQ signal according to a preset shaping lookup table, wherein the preset shaping lookup table is used for storing the corresponding relation between the envelope and the envelope tracking signal, and the first envelope tracking signal is used for representing an envelope tracking expected voltage;

carrying out envelope tracking modulation according to the first envelope tracking signal;

acquiring a second envelope tracking signal according to a first envelope tracking voltage obtained by envelope tracking modulation;

determining a parameter value sequence of a calibration parameter according to the first envelope tracking signal and the second envelope tracking signal;

adjusting the first envelope tracking signal according to the parameter value sequence of the calibration parameter;

carrying out envelope tracking modulation according to the adjusted third envelope tracking signal;

inputting a second envelope tracking voltage obtained by envelope tracking modulation into a power amplifier, so that the power amplifier processes a radio frequency signal according to the second envelope tracking voltage, wherein the error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than the error between the first envelope tracking voltage and the envelope tracking expected voltage.

2. The method of claim 1, wherein determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal comprises:

determining a frequency response characteristic of an envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal;

determining the frequency response characteristic of a calibration unit according to the frequency response characteristic of the envelope tracking modulator, wherein the product of the frequency response characteristic of the envelope tracking modulator and the frequency response characteristic of the calibration unit is a preset constant;

and determining a parameter value sequence of the calibration parameters according to the frequency response characteristic of the calibration unit.

3. The method of claim 1, wherein determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal comprises:

determining a desired input signal for an envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal;

operating on the first envelope tracking signal and a desired input signal of the envelope tracking modulator using an adaptive algorithm;

and when the error obtained by the operation is smaller than the preset error, determining the parameter value sequence corresponding to the error obtained by the operation as the parameter value sequence of the calibration parameter.

4. The method of claim 3, wherein the adaptive algorithm is a least mean square algorithm or a least squares algorithm.

5. The method of claim 1, wherein determining the sequence of parameter values for the calibration parameters from the first envelope tracking signal and the second envelope tracking signal comprises:

and processing the first envelope tracking signal and the expected input signal of the envelope tracking modulator by using a neural network algorithm to obtain a parameter value sequence of the calibration parameter.

6. The method according to any one of claims 1 to 5, wherein the calibration parameters are filter coefficients, equalizer coefficients, fitting coefficients of a spline function or fitting coefficients of a polynomial.

7. A signal processing method, comprising:

determining a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping look-up table, wherein the first envelope tracking signal is used for indicating an envelope tracking expected voltage;

converting a first envelope tracking voltage obtained by envelope tracking modulation into a second envelope tracking signal;

adjusting the envelope of the IQ signal according to the parameter value sequence of the calibration parameter;

determining a third envelope tracking signal corresponding to the adjusted envelope according to a preset shaping look-up table;

carrying out envelope tracking modulation according to the third envelope tracking signal;

8. The method of claim 7, wherein determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal comprises:

9. The method of claim 7, wherein determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal comprises:

10. The method of claim 9, wherein the adaptive algorithm is a least mean square algorithm or a least squares algorithm.

11. The method of claim 7, wherein determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal comprises:

12. The method according to any of claims 7 to 11, wherein the calibration parameters are filter coefficients, equalizer coefficients, fitting coefficients of a spline function or fitting coefficients of a polynomial.

13. A signal processing method, comprising:

determining a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping lookup table, wherein the first envelope tracking signal is used for indicating an envelope tracking expected voltage;

inputting a first envelope tracking voltage obtained by envelope tracking modulation into a power amplifier;

determining a second envelope tracking signal corresponding to the output power of the power amplifier according to the shaping look-up table;

correcting the first envelope tracking signal according to the parameter value sequence of the calibration parameter to obtain a third envelope tracking signal;

and inputting a second envelope tracking voltage obtained by envelope tracking modulation into a power amplifier, wherein the error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than the error between the first envelope tracking voltage and the envelope tracking expected voltage.

14. The method of claim 13, wherein determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal comprises:

15. The method of claim 13, wherein determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal comprises:

16. The method of claim 15, wherein the adaptive algorithm is a least mean square algorithm or a least squares algorithm.

17. The method of claim 13, wherein determining the sequence of parameter values for the calibration parameter from the first envelope tracking signal and the second envelope tracking signal comprises:

18. The method according to any of claims 13 to 17, wherein the calibration parameters are filter coefficients, equalizer coefficients, fitting coefficients of a spline function or fitting coefficients of a polynomial.

19. The method according to any one of claims 13 to 17,

after the first envelope tracking voltage obtained by envelope tracking modulation is input into the power amplifier, the method further comprises:

determining a direct current offset error according to the zero-frequency voltage of the second envelope tracking signal and the zero-frequency voltage of the first envelope tracking signal;

determining a direct-current component adjustment quantity according to the direct-current offset error, wherein the direct-current component adjustment quantity is the inverse number of the direct-current offset error;

after the modifying the first envelope tracking signal according to the sequence of parameter values of the calibration parameter to obtain a third envelope tracking signal, the method further includes:

and adjusting the direct-current component of the third envelope tracking signal according to the direct-current component adjustment amount.

20. The method according to any one of claims 13 to 17,

acquiring a signal index of a radio frequency signal output by the power amplifier, wherein the signal index comprises an adjacent channel power leakage ratio or an error vector amplitude;

and when the signal index is greater than or equal to a preset threshold value, increasing the direct current component of the third envelope tracking signal according to a preset increment.

21. A signal processing apparatus, characterized by comprising:

the amplitude-phase conversion unit is used for carrying out amplitude-phase conversion on the input in-phase quadrature IQ signal to obtain the envelope of the IQ signal;

a shaping lookup table unit, configured to determine a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping lookup table, where the preset shaping lookup table is used to store a corresponding relationship between the envelope and the envelope tracking signal, and the first envelope tracking signal is used to represent an envelope tracking expected voltage;

an envelope tracking modulator for performing envelope tracking modulation based on the first envelope tracking signal;

the processing unit is used for acquiring a second envelope tracking signal according to the first envelope tracking voltage obtained by envelope tracking modulation;

the processing unit is further configured to determine a parameter value sequence of a calibration parameter according to the first envelope tracking signal and the second envelope tracking signal;

the calibration unit is used for adjusting the first envelope tracking signal according to the parameter value sequence of the calibration parameter;

the envelope tracking modulator is also used for carrying out envelope tracking modulation according to the adjusted third envelope tracking signal; inputting a second envelope tracking voltage obtained by envelope tracking modulation into a power amplifier, so that the power amplifier processes a radio frequency signal according to the second envelope tracking voltage, and the mean square error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than that between the first envelope tracking voltage and the envelope tracking expected voltage.

22. The apparatus of claim 21,

the processing unit is specifically configured to determine a frequency response characteristic of an envelope tracking modulator according to the first envelope tracking signal and the second envelope tracking signal; determining the frequency response characteristic of a calibration unit according to the frequency response characteristic of the envelope tracking modulator, wherein the product of the frequency response characteristic of the envelope tracking modulator and the frequency response characteristic of the calibration unit is a preset constant;

23. The apparatus of claim 21,

the processing unit is specifically configured to determine an expected input signal of an envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; operating on the first envelope tracking signal and a desired input signal of the envelope tracking modulator using an adaptive algorithm; and when the error obtained by the operation is smaller than the preset error, determining the parameter value sequence corresponding to the error obtained by the operation as the parameter value sequence of the calibration parameter.

24. The apparatus of claim 23, wherein the adaptive algorithm is a least mean square error algorithm or a least squares algorithm.

25. The apparatus of claim 21,

the processing unit is specifically configured to determine an expected input signal of an envelope tracking modulator from the first envelope tracking signal and the second envelope tracking signal; and processing the first envelope tracking signal and the expected input signal of the envelope tracking modulator by using a neural network algorithm to obtain a parameter value sequence of the calibration parameter.

26. The apparatus of any one of claims 21 to 25, wherein the calibration parameters are filter coefficients, equalizer coefficients, fitting coefficients of a spline function, or fitting coefficients of a polynomial.

27. A signal processing apparatus, characterized by comprising:

a shaping lookup table unit, configured to determine a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping lookup table, where the first envelope tracking signal is used to indicate an envelope tracking expected voltage;

the processing unit is used for converting the first envelope tracking voltage obtained by envelope tracking modulation into a second envelope tracking signal;

the calibration unit is used for adjusting the envelope of the IQ signal according to the parameter value sequence of the calibration parameter;

the shaping lookup table unit is further configured to determine a third envelope tracking signal corresponding to the adjusted envelope according to a preset shaping lookup table;

the envelope tracking modulator is further configured to perform envelope tracking modulation according to the third envelope tracking signal; inputting a second envelope tracking voltage obtained by envelope tracking modulation into a power amplifier, so that the power amplifier processes an input radio frequency signal according to the second envelope tracking voltage, wherein the error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than the error between the first envelope tracking voltage and the envelope tracking expected voltage.

28. The apparatus of claim 27,

the processing unit is specifically configured to determine a frequency response characteristic of an envelope tracking modulator according to the first envelope tracking signal and the second envelope tracking signal; determining the frequency response characteristic of a calibration unit according to the frequency response characteristic of the envelope tracking modulator, wherein the product of the frequency response characteristic of the envelope tracking modulator and the frequency response characteristic of the calibration unit is a preset constant; and determining a parameter value sequence of the calibration parameters according to the frequency response characteristic of the calibration unit.

29. The apparatus of claim 27,

30. The apparatus of claim 29, wherein the adaptive algorithm is a least mean square error algorithm or a least squares algorithm.

31. The apparatus of claim 27,

32. The apparatus of any one of claims 27 to 31, wherein the calibration parameters are filter coefficients, equalizer coefficients, fitting coefficients of a spline function, or fitting coefficients of a polynomial.

33. A signal processing apparatus, characterized by comprising:

a shaping lookup table unit, configured to determine a first envelope tracking signal corresponding to an envelope of the IQ signal according to a preset shaping lookup table, where the first envelope tracking signal is used to indicate an envelope tracking desired voltage;

an envelope tracking modulator for performing envelope tracking modulation based on the first envelope tracking signal; inputting a first envelope tracking voltage obtained by envelope tracking modulation into a power amplifier;

a processing unit, configured to determine a second envelope tracking signal corresponding to the output power of the power amplifier according to the shaping lookup table;

the calibration unit is used for correcting the first envelope tracking signal according to the parameter value sequence of the calibration parameter to obtain a third envelope tracking signal;

the envelope tracking modulator is further configured to perform envelope tracking modulation according to the third envelope tracking signal; and inputting a second envelope tracking voltage obtained by envelope tracking modulation into a power amplifier, wherein the error between the second envelope tracking voltage and the envelope tracking expected voltage is smaller than the error between the first envelope tracking voltage and the envelope tracking expected voltage.

34. The apparatus of claim 33,

35. The apparatus of claim 33,

36. The apparatus of claim 35, wherein the adaptive algorithm is a least mean square error algorithm or a least squares algorithm.

37. The apparatus of claim 33,

38. The apparatus of any one of claims 33 to 37, wherein the calibration parameter is a filter coefficient, an equalizer coefficient, a fitting coefficient of a spline function, or a fitting coefficient of a polynomial.

39. The apparatus of any one of claims 33 to 37,

the processing unit is further configured to determine a direct current offset error according to the zero-frequency voltage of the second envelope tracking signal and the zero-frequency voltage of the first envelope tracking signal;

the signal processing apparatus further includes:

and the direct current offset unit is used for adjusting the direct current component of the third envelope tracking signal according to the direct current component adjustment quantity after the calibration unit corrects the first envelope tracking signal according to the parameter value sequence of the calibration parameter to obtain a third envelope tracking signal.

40. The apparatus of any one of claims 33 to 37,

the processing unit is further configured to obtain a signal indicator of the radio frequency signal output by the power amplifier, where the signal indicator includes an adjacent channel power leakage ratio or an error vector magnitude;

the signal processing apparatus further includes:

and the direct current offset unit is used for increasing the direct current component of the third envelope tracking signal according to a preset increment when the signal index is greater than or equal to a preset threshold value.

41. A terminal, comprising:

processor, memory, baseband unit, radio frequency module, antenna and signal processing device according to any of claims 21 to 40, the processor, memory and the baseband unit being connected by a bus, the radio frequency module being connected to the baseband unit, the signal processing device and the antenna, respectively.

42. A network device, comprising:

43. A computer storage medium comprising instructions that, when executed on a computer, cause the computer to perform a signal processing method according to any one of claims 1 to 20.