Digital predistortion process apparatus and updating method of digital predistorter

Abstract

The invention discloses a digital predistortion processing device which includes a pre-distorter, a self-adapting updating module, a control module and a calibration sequence generation model used for generating the source calibration sequence and providing the source calibration sequence for the pre-distorter; the self-adapting updating module is used for acquiring the feedback calibration sequence from the power amplification output; the latest pre-distorter is obtained according to the source calibration sequence and the feedback calibration sequence; the pre-distorter is used for storing the predistortion function, processing the source calibration sequence and the source signal through the predistortion function and sending the processed source calibration sequence and source signal to the power amplifier; meanwhile, the latest predistortion function of the self-adapting updating module can be adopted to update the predistortion function stored in the self-adapting updating module; the control module is used for controlling the pre-distorter, the self-adapting updating module and the calibration sequence generation module for coordination operation. The digital predistortion processing device adopts the newly-constructed calibration sequence to control all the amplitudes from the minimum value to the peak value; namely, the pre-distorter can be updated so that the updating speed is improved and the algorithm difficulty is simplified. The digital predistortion processing device also provides an updating method of the digital pre-distorter.

Description

technical field [0001] The invention relates to digital pre-distortion processing technology, in particular to a digital pre-distortion processing device in a time-division communication system and a method for updating a digital pre-distortion device. Background technique [0002] The power amplifier (Power Amplifier, PA, hereinafter referred to as the power amplifier) ​​is an indispensable part of a communication system. Due to the nonlinear characteristics of the transistor itself, the input and output characteristics of the power amplifier that has not been linearized are nonlinear, especially the input signal The larger part will be more distorted. Non-linearity will generate spectrum regrowth, which will lead to adjacent channel interference, so that the system cannot meet the strict out-of-band radiation requirements; non-linearity will also cause in-band interference, which will reduce the bit error rate performance of the system. [0003] Among all linearization te...

AI Technical Summary

Problems solved by technology

This method has defects such as slow update speed and complex implementation. The specific reasons are as follows:

[0008] 1) Predistorter update speed is slow

[0009] The reason is that, in a normal service flow, the signal whose amplitude is near the mean value has the highest probability of appearing, and the closer to the peak value, the lower the probability of appearing. It takes a long time to wait for all source signals of all possible amplitudes to appear. The peak signal is the most distorted in the power amplifier and needs to be updated most. Therefore, it will be very slow to update all the LUTs once, and it is difficult to achieve rapid adaptive changes with the system.

[0010] 2) The adaptive algorithm is complex

[0013] Due to the processing of a large number of source signals and feedback signals, the adaptive algorithm is very complicated, and the hardware requirements of the whole system are very high. Some systems even need to add additional DSP processors to run the algorithm, which increases the system cost, power consumption and plate making. difficulty

[0014] For polynomial-based predistorters, similar problems as above exist, and are more severe

Images