Power injection type multi-channel self-adaptive digital pre-distortion algorithm and system

Abstract

The invention discloses a power injection type multi-channel self-adaptive digital pre-distortion algorithm and system, which adopt a direct learning architecture to construct modules, and have the characteristics of simple structure and convenience in implementation. The pre-distortion signal is composed of three parts: an original baseband signal and two kinds of low-power baseband signals generated by two pre-distortion sub-modules. A low-power signal is obtained through the first pre-distortion sub-module and the second pre-distortion sub-module and injected into a baseband input signal to compensate nonlinearity, memory effect and crosstalk effect of a power amplifier in the MIMO system, and when the PAPR value of a baseband signal is large and the nonlinearity of the power amplifier is strong, a good linearization effect can still be obtained in each branch. The pre-distortion signal is amplified by the power amplifier, the out-of-band spectrum expansion and the in-band distortion can be well inhibited by observing the characteristics of the output signal, the problems of nonlinearity, memory effect and crosstalk of the power amplifier in the MIMO system are solved, and the efficiency of the power amplifier in the MIMO system is improved.

Description

technical field [0001] The present invention relates to the technical field of wireless communication, in particular to a power injection type multi-channel adaptive digital predistortion (DPD) algorithm and system. Background technique [0002] A typical multiple-input multiple-output-orthogonal frequency-division multiplexing (MIMO-OFDM) transmitter architecture has been proposed in 4G, which significantly improves the system transmission rate and spectral efficiency on the basis of frequency selective fading, multipath interference. These problems can also be effectively solved. The combination of MIMO technology and OFDM technology ensures that the communication system can achieve high transmission rate and strong system reliability. [0003] In 5G-NR, massive MIMO technology is extremely effective in improving channel capacity, spectral efficiency, and data throughput. 5G base stations need to comply with their respective transmission requirements or conduction require...

AI Technical Summary

Problems solved by technology

The application indicators of the base station include: base station output power, transmission signal quality, signal bandwidth, adjacent channel leakage ratio, harmful radiation in the working frequency band, spurious radiation of the transmitter, intermodulation of the transmitter, etc.; radio frequency (RF) power amplifier (PA) in the base station The impact of the quality of the performance on these indicators is particularly critical. The inherent nonlinearity of the RF power amplifier and the memory effect when transmitting broadband signals, as well as the crosstalk effect applied in massive MIMO scenarios deteriorate the performance of the communication system and affect the performance of the communication system. Signal Transmission Quality

[0004] Compared with the traditional single-input single-output (SISO) system, the predistorter at the transmitting end of the MIMO system faces more technical challenges. Since the transmitter performs up-conversion on multiple signals at the same time, there are multiple branches on the same chip. Crosstalk will occur between multiple branches when the chip size is small, and the effect of crosstalk will be more significant when the chip size is small, which will directly lead to the distortion of the output signal of the RF power amplifier, and then affect the accuracy of the predistorter coefficient estimation stage, reducing the The performance of the predistortion technology

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