An Adaptive High-Efficiency 5G Digital Predistortion Power Amplifier and Its Control Method

Abstract

The present invention relates to an adaptive high-efficiency 5G digital pre-distortion power amplifier, which includes a baseband signal converting intermediate frequency signal + peak clipping processing unit, a digital pre-distortion processing unit, a data storage unit, an adaptive processing unit, a control unit, up-conversion, down-conversion, a local oscillator and a power amplifier; the baseband signal converting intermediate frequency signal + peak clipping processing unit is respectively connected to the digital pre-distortion processing unit, the control unit and the data storage unit; the digital pre-distortion processing unit is connected to the up-conversion; the digital pre-distortion processing unit is also connected to the data storage unit; the adaptive processing unit is respectively connected to the digital pre-distortion processing unit, the data storage unit and the control unit; the adaptive processing unit is connected to the down-conversion; the local oscillator is respectively connected to the up-conversion and the down-conversion; the up-conversion is also connected to the power amplifier. The present invention effectively solves the problem of adaptively pre-distorting and amplifying signals with different peak-to-average ratios at the same frequency, improves the efficiency of the power amplifier, and reduces the cost of the power amplifier.

Description

Technical Field

[0001] The present invention relates to the field of mobile communication technologies, and particularly to an adaptive high-efficiency 5G digital pre-distortion power amplifier and its control method. Background Art

[0002] For the large-scale application of 5G, breaking through and implementing the "last mile" has become the focus and difficulty that operators are concerned about. It is understood that currently more than 60% of typical 5G applications occur indoors. Since 5G communication uses a signal transmission frequency higher than that of 4G LTE, the 5G signal transmitted by the base station cannot reach indoors from outdoors. Therefore, deeply cultivating indoor coverage is the key to improving 5G traffic volume and making it useful for the people. With the continuous improvement of 5G macro stations in each province, the repeater will provide a strong supplement to the macro station.

[0003] The requirements for LTE / NR bandwidth in the telecom joint refarming plan are different, and there are co-frequency LTE / NR plans with bandwidths of 50M, 40M, 20M, 10M, and 5M. The peak-to-average power ratio (PAPR) of telecom joint 5G NR is 8.5, and the PAPR of 4G LTE is 8. The PAPR values mixed under different telecom joint refarming plans are different. The original digital pre-distortion technology can only effectively perform digital pre-distortion processing on signals with the same PAPR, and cannot effectively perform digital pre-distortion processing on signals with different PAPRs. To ensure equipment consistency, it is necessary to ensure that a power amplifier can adaptively amplify signals under different telecom joint refarming plans. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an adaptive high-efficiency 5G digital pre-distortion power amplifier and its control method, which effectively solve the problem of adaptively pre-distorting and amplifying signals with different PAPRs in the same frequency, improve the power amplifier efficiency, and reduce the power amplifier cost.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] An adaptive high-efficiency 5G digital pre-distortion power amplifier includes a baseband signal converting to intermediate frequency signal + peak clipping processing unit, a digital pre-distortion processing unit, a data storage unit, an adaptive processing unit, a control unit, upconversion, downconversion, a local oscillator, and a power amplifier; the baseband signal converting to intermediate frequency signal + peak clipping processing unit is respectively connected to the digital pre-distortion processing unit, the control unit, and the data storage unit; the digital pre-distortion processing unit is connected to the upconversion through a DAC module; the digital pre-distortion processing unit is also connected to the data storage unit; the adaptive processing unit is respectively connected to the digital pre-distortion processing unit, the data storage unit, and the control unit; the adaptive processing unit is also connected to the downconversion through an ADC module; the local oscillator is respectively connected to the upconversion and the downconversion; the upconversion is also connected to the power amplifier.

[0007] Furthermore, the digital pre-distortion processing unit uses an FPGA device, which is used to receive the signal from the baseband signal converted intermediate frequency signal + peak clipping processing unit, receive the pre-distortion coefficient from the peak clipping / pre-distortion look-up table for pre-distortion correction, and has a parameter update module built-in to be responsible for parameter update.

[0008] Furthermore, the adaptive processing unit uses a high-speed DSP, which is used to receive the signal collected by the digital pre-distortion processing unit, the signal coupled from the power amplifier output, the peak-to-average ratio acquisition signal of the control unit, and the power amplifier temperature, as the compensation coefficient of the input signal, and is used to control the look-up and update of the peak clipping / pre-distortion coefficient.

[0009] Furthermore, the control unit uses an ARM device, which is used to receive the power amplifier temperature parameter and the parameter collected by the peak-to-average ratio signal, and send the processed data to the adaptive processing unit for adaptive data analysis and processing.

[0010] Furthermore, the data storage unit is provided with a peak clipping / pre-distortion look-up table, specifically including:

[0011] (1) By repeatedly training the signal source composed of different signals mixed and the different voltages, peak-to-average ratio values, etc. fed back, the peak clipping / pre-distortion values are stored;

[0012] (2) After the device is started, the peak clipping / pre-distortion look-up table first looks up through the data sent back by the adaptive processing unit, finds the corresponding value, and sends the CFR coefficient and the pre-distortion coefficient to the corresponding baseband signal converted intermediate frequency signal + peak clipping processing unit and digital pre-distortion processing unit.

[0013] A control method for an adaptive high-efficiency 5G digital pre-distortion power amplifier includes the following steps:

[0014] Step S1: Combine the digital pre-distortion technology and the peak clipping technology to convert the baseband signal to be input into the digital pre-distortion processing unit into an intermediate frequency signal and perform peak clipping processing;

[0015] Step S2: The signal from the baseband signal converted intermediate frequency signal + peak clipping processing unit is transmitted to the digital pre-distortion processing unit for digital pre-distortion processing;

[0016] Step S3: The output signal after pre-distortion processing is converted into an analog quadrature signal through the DAC module;

[0017] Step S4: The signal converted by the DAC module is up-converted and filtered to obtain a radio frequency signal and output to the power amplifier;

[0018] Step S5: Couple a path of signal at the output end of the power amplifier as a feedback signal, which becomes an analog intermediate frequency signal after down-conversion. The analog intermediate frequency signal is then converted back into a digital intermediate frequency signal by the ADC module and enters the adaptive processing unit.

[0019] Step S6: The control unit statistically processes the data collected by acquiring the power amplifier temperature and the peak-to-average ratio signal of the baseband signal conversion intermediate frequency signal + peak clipping processing unit, and transmits the signal to the adaptive processing unit.

[0020] Step S7: The adaptive processing unit compares and calculates the feedback signal, input signal, peak-to-average ratio signal, and temperature information to generate a new peak clipping / pre-distortion parameter value. By querying the peak clipping / pre-distortion look-up table, a new pre-distortion coefficient and CFR coefficient are generated.

[0021] The present invention has the following beneficial effects compared with the prior art:

[0022] The present invention effectively solves the problem of adaptively pre-distorting and amplifying signals with the same frequency but different peak-to-average ratios, improves the power amplifier efficiency, and reduces the power amplifier cost. Brief Description of the Drawings

[0023] Figure 1 is the principle block diagram of the present invention;

[0024] Figure 2 is the workflow diagram in an embodiment of the present invention;

[0025] Figure 1 In the figure: 1 - Baseband signal conversion intermediate frequency signal + peak clipping processing unit, 2 - Digital pre-distortion processing unit, 3 - Adaptive processing unit, 4 - Control unit, 5 - Peak clipping / pre-distortion look-up table, 6 - DAC, 7 - ADC, 8 - Up-conversion module, 9 - Down-conversion module, 10 - Power amplifier, 20 - Digital pre-distortion module, 30 - Analog-to-digital / digital-to-analog conversion module, 40 - Frequency conversion module. Detailed Embodiments

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] Please refer to Figure 1, the present invention provides an adaptive high-efficiency 5G digital pre-distortion power amplifier, which includes a baseband signal converting intermediate frequency signal + crest factor reduction processing unit, a digital pre-distortion processing unit, a data storage unit, an adaptive processing unit, a control unit, an up-conversion unit, a down-conversion unit, a local oscillator, and a power amplifier; the baseband signal converting intermediate frequency signal + crest factor reduction processing unit is respectively connected to the digital pre-distortion processing unit, the control unit, and the data storage unit; the digital pre-distortion processing unit is connected to the up-conversion unit through a DAC module; the digital pre-distortion processing unit is also connected to the data storage unit; the adaptive processing unit is respectively connected to the digital pre-distortion processing unit, the data storage unit, and the control unit; the adaptive processing unit is also connected to the down-conversion unit through an ADC module; the local oscillator is respectively connected to the up-conversion unit and the down-conversion unit; the up-conversion unit is also connected to the power amplifier.

[0028] In this embodiment, the digital pre-distortion processing unit uses an FPGA device, which is used to receive the signal after the baseband signal converting intermediate frequency signal + crest factor reduction processing unit, receive the pre-distortion coefficient from the crest factor reduction / pre-distortion look-up table for pre-distortion correction, and internally has a parameter update module responsible for parameter update.

[0029] In this embodiment, the adaptive processing unit uses a high-speed DSP, which is used to receive the signal collected by the digital pre-distortion processing unit, the signal coupled from the output of the power amplifier, the peak-to-average ratio acquisition signal of the control unit, and the temperature of the power amplifier as the compensation coefficient of the input signal, and is used to control the search and update of the crest factor reduction / pre-distortion coefficient

[0030] In this embodiment, the control unit uses an ARM device, which is used to receive the temperature parameter of the power amplifier and the parameter collected by the peak-to-average ratio signal, and send the processed data to the adaptive processing unit for adaptive data analysis and processing.

[0031] In this embodiment, the data storage unit is provided with a crest factor reduction / pre-distortion look-up table, specifically including:

[0032] (1) By repeatedly training the signal source composed of different signals and the feedback of different voltages, peak-to-average ratio values, etc., store the crest factor reduction / pre-distortion values;

[0033] (2) After the device is started, the crest factor reduction / pre-distortion look-up table first searches through the data sent back by the adaptive processing unit, finds the corresponding value, and sends the CFR coefficient and the pre-distortion coefficient to the corresponding baseband signal converting intermediate frequency signal + crest factor reduction processing unit and digital pre-distortion processing unit.

[0034] Preferably, the crest cancellation / pre-distortion lookup table performs a large amount of signal training at the factory, and the generated parameters are first stored in the crest cancellation / pre-distortion lookup table. After the device is powered on / resetted, the data is first subjected to crest cancellation and pre-distortion processing using the factory preset CFR coefficient and pre-distortion coefficient, and the preset values are obtained from a large amount of signal training analysis. Then, parameter analysis is performed based on the collected output signal, power amplifier temperature, and peak-to-average ratio data. After analysis and processing by the adaptive processing unit, the corresponding lookup coefficients are given, and then new CFR coefficients and pre-distortion coefficients are sent to the corresponding processing units by querying the crest cancellation / pre-distortion lookup table. This process repeats until the adaptive processing unit analyzes that the feedback power amplifier signal index no longer deteriorates, and the device automatically enters the follow-up mode to complete the adaptive correction.

[0035] In this embodiment, a control method for an adaptive high-efficiency 5G digital pre-distortion power amplifier is further provided, including the following steps:

[0036] Step S1: Combining digital pre-distortion technology and crest cancellation technology, convert the baseband signal to be input into the digital pre-distortion processing unit into an intermediate frequency signal and perform crest cancellation processing;

[0037] Step S2: Transmit the signal from the baseband signal conversion intermediate frequency signal + crest cancellation processing unit to the digital pre-distortion processing unit for digital pre-distortion processing;

[0038] Step S3: The output signal after pre-distortion processing is converted into an analog quadrature signal through the DAC module;

[0039] Step S4: The signal transformed by the DAC module is up-converted and filtered to obtain a radio frequency signal and output to the power amplifier;

[0040] Step S5: Couple a signal at the output end of the power amplifier as a feedback signal, convert it into an analog intermediate frequency signal after down-conversion, and the analog intermediate frequency signal is converted back into a digital intermediate frequency signal through the ADC module and enters the adaptive processing unit;

[0041] Step S6: The control unit collects and statistically processes the data by collecting the power amplifier temperature and the peak-to-average ratio signal of the baseband signal conversion intermediate frequency signal + crest cancellation processing unit, and transmits the signal to the adaptive processing unit;

[0042] Step S7: The adaptive processing unit compares and calculates the feedback signal, input signal, peak-to-average ratio signal, and temperature information to generate new crest cancellation / pre-distortion parameter values, and generates new pre-distortion coefficients and CFR coefficients by querying the crest cancellation / pre-distortion lookup table.

[0043] The above are only the preferred embodiments of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims

1. An adaptive high-efficiency 5G digital pre-distortion power amplifier, characterized in that, It includes a baseband signal converting to intermediate frequency signal + peak clipping processing unit, a digital pre-distortion processing unit, a data storage unit, an adaptive processing unit, a control unit, up-conversion, down-conversion, a local oscillator and a power amplifier; the baseband signal converting to intermediate frequency signal + peak clipping processing unit is respectively connected to the digital pre-distortion processing unit, the control unit and the data storage unit; the digital pre-distortion processing unit is connected to the up-conversion through a DAC module; the digital pre-distortion processing unit is also connected to the data storage unit; the adaptive processing unit is respectively connected to the digital pre-distortion processing unit, the data storage unit and the control unit; the adaptive processing unit is also connected to the down-conversion through an ADC module; the local oscillator is respectively connected to the up-conversion and the down-conversion; the up-conversion is also connected to the power amplifier; The adaptive processing unit uses a high-speed DSP, which is used to receive the signals collected by the digital pre-distortion processing unit, the signals coupled from the output of the power amplifier, the peak-to-average ratio acquisition signals of the control unit and the temperature of the power amplifier, as the compensation coefficients of the input signals, and is used to control the search and update of the peak clipping / pre-distortion coefficients; The control unit uses an ARM device, which is used to receive the temperature parameters of the power amplifier and the parameters collected by the peak-to-average ratio signal acquisition, and send the processed data to the adaptive processing unit for adaptive data analysis and processing; The data storage unit is provided with a peak clipping / pre-distortion look-up table, specifically including: (1) By repeatedly training the signal sources composed of different signals and the different voltages and peak-to-average ratio values fed back, the peak clipping / pre-distortion values are stored; (2) After the device is started, the peak clipping / pre-distortion look-up table searches through the data sent back by the adaptive processing unit, finds the corresponding values, and sends the CFR coefficients and pre-distortion coefficients to the corresponding baseband signal converting to intermediate frequency signal + peak clipping processing unit and digital pre-distortion processing unit.

2. The adaptive high-efficiency 5G digital pre-distortion power amplifier according to claim 1, characterized in that, The digital pre-distortion processing unit uses an FPGA device, which is used to receive the signals after the baseband signal converting to intermediate frequency signal + peak clipping processing unit, receive the pre-distortion coefficients from the peak clipping / pre-distortion look-up table for pre-distortion correction, and internally has a parameter update module responsible for parameter update.

3. A control method for the adaptive high-efficiency 5G digital pre-distortion power amplifier according to any one of claims 1-2, characterized in that, It includes the following steps: Step S1: Combining the digital pre-distortion technology and the peak clipping technology, convert the baseband signal to be input into the digital pre-distortion processing unit into an intermediate frequency signal and perform peak clipping processing; Step S2: Transmit the signals from the baseband signal converting to intermediate frequency signal + peak clipping processing unit to the digital pre-distortion processing unit for digital pre-distortion processing; Step S3: The output signal after pre-distortion processing is converted into an analog quadrature signal through a DAC module; Step S4: The signal converted by the DAC module is up-converted and filtered to obtain a radio frequency signal and output to the power amplifier; Step S5: Couple a signal at the output end of the power amplifier as a feedback signal, convert it into an analog intermediate frequency signal after down-conversion, and the analog intermediate frequency signal is converted back into a digital intermediate frequency signal through an ADC module and enters the adaptive processing unit; Step S6: The control unit statistically processes the signals collected by acquiring the temperature of the power amplifier and the peak-to-average ratio signals of the baseband signal converting to intermediate frequency signal + peak clipping processing unit, and transmits the signals to the adaptive processing unit; Step S7: The adaptive processing unit compares and calculates the feedback signal, input signal, PAPR signal, and temperature information to generate a new peak clipping / pre-distortion parameter value. By querying the peak clipping / pre-distortion lookup table, a new pre-distortion coefficient and CFR coefficient are generated.

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