Digital predistortion device and method for band-limited simplified nonlinear filter

Abstract

The invention provides a digital predistortion device and method for a band-limited simplified nonlinear filter. The device comprises a digital predistorter and a predistortion model training module of a predistortion model based on band limited simplified nonlinear filtering; the digital predistorter performs digital predistortion processing on an input digital baseband signal; a power amplifier outputs an analog radio frequency signal, generates an output digital baseband signal after the analog radio frequency signal is subjected to power coupling by an attenuation coupler, quadrature demodulation by a wideband quadrature demodulator, low-pass filtering by a low-pass filter and analog-to-digital conversion of a low sampling frequency, and inputs the output digital baseband signal after the input digital baseband signal and the output digital baseband signal are synchronized into a predistorter training module; the predistorter training module uses the least square algorithm to perform parameter training and then obtains power amplifier model parameters based on a band limited simplified nonlinear filter function, and sends the power amplifier model parameters to the digital predistorter. The invention uses the band limited method on a nonlinear filter function model to reduce the sampling frequency of a digital predistortion analog-to-digital converter, thereby reducing the difficulty and cost of realizing digital predistortion.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to a digital predistortion device and method based on a band-limited simplified nonlinear filter. Background technique [0002] With the wide application of the fourth-generation mobile communication system and the in-depth research on the fifth-generation mobile communication technology, the data traffic of the communication system is increasing day by day. The modulation method leads to a higher peak-to-average ratio of the signal. The peak-to-average ratio of the broadband baseband signal has high requirements on the linearity of the RF power amplifier. [0003] High-speed DAC and ADC will increase system power consumption and cost, which has become the bottleneck of the current digital pre-distortion technology development. How to use low-speed DAC and ADC to realize digital pre-distortion with wider signal bandwidth is also becoming a research hotspot and devel...

AI Technical Summary

Problems solved by technology

[0007] Purpose of the invention: Aiming at the problem that broadband signals cause the sampling frequency of analog-to-digital converters to be too high, and the Volterra series model behavior model is complex, the present invention provides a digital predistortion device and method based on a band-limited simplified nonlinear filter, The present invention effectively reduces the sampling frequency of the analog-to-digital converter by using the band-limited method

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