Design And Implementation Of Radio Frequency Power Amplifier Digital Pre-distortion Technology On The Soft-core

A RF po wer amplifier is an indispensable part in wireless communication system,which is used to magnify the power of the signal.Its working characteristic has a significant effect on the performance of the communication system.But the nonlinear effect of the amplifier will cause nonlinear distortion in the process.Therefore,it is necessary to reduce the distortion effect of the amplifier,improve the error rate and increase the utilization rate of the spectrum.Technical experts have proposed various techniques to improve the distortion characteristics of RF power amplifiers.Because it is simple and efficient,digital predistortion is the most popular one among these techniques.In this paper,the baseband digital predistortion has been realized through the combination of Micro Blaze and FPGA.The Soft-core is a Programmable chip system inside the FPGA(Field Programmable Gate Array),which is used to calculate the predistortion algorithm.The specific content of this study is as follows.Firstly,distortion characteristics of the RF power amplifier and its common behavior model are introduced in details.After a careful study of baseband digital predistortion technology,the overall design scheme has been proposed.The minimum mean square error algorithm is determined as the predistortion algorithm in the scheme,and the parameters of the predistorter are determined by simulation.Secondly,the baseband digital predistortion technology has been realized through the combination of soft core and FPGA which is based on the proposed overall design scheme.Then the total implementation block diagram of the overall design scheme is determined.The block diagram is divided into the soft core,the FPGA and the data interaction.The principle and realization of each functional module in block diagram are introduced in detail.Thirdly,FPGA engineering link is constructed by using soft core and FPGA,and the overall design scheme of the proposed baseband digital predistortion technology is tested and analyzed.This paper verifies the correctness of the proposed scheme for realizing baseband digital predistortion.The method of combining the soft core with FPGA is low cost and has certain value in engineering.