The FPGA Implementation Of Digital Module Of WCDMA Repeater

Along with fast development of information technical, the communicate abilityof2G has already can not satisfied the business requirement of people．The narrowband digital communication system is developing gradually to the3G mobilecommunication system．WCDMA repeater will be all important part of the mobilecommunication system．The Repeater not only increase the network cover ability,extend the base station, but also increase the telephone traffic load of the idle basestation and optimize the net work．Repeater can be flexible placed in the signal blindarea like underground and emporium．Adopt base station as principle，repeater asmakeup is very meaningful. The digital intermediate frequency is not only one of theimportant technologies in the WCDMA repeater, but also unavoidable issue of itsapplication.This paper introduces the FPGA application of Digital Intermediate Frequency inWCDMA150W Power Amplifier. The main contents are focused on the analysis,design and application of Digital Intermediate Frequency, which includes A/DConverter, D/A Converter, Digital Down-Converter, Digital Up-Converter and DigitalPre-distortion. This article first has focused on the simple introduction to the topic’stechnology background， including WCDMA， repeaters and the digital IFtechnology．Based on these，the digital IF theory which involved to the topic isillustrated in detail．And then the specification of the key modules in the DigitalIntermediate Frequency is based on the WCDMA. And Making the analysis andsoftware simulation for Digital Converter and DPD, included AGC and power detectmodule. The author also provides the hardware solution which both AD/DA chip’schoices and hardware debugging. Finally the function of digital board tested,including: Digital Converter function test, digital pre-distortion, AGC and powerdetect functional testing. And verified with the RF and amplifier module to test thekey indicators of digital module EVM, ACPR and PCDE whether meet the designrequirements.It is discovered from the test results that the digital module of WCDMA repeater can satisfy basically3GPP related standards. The test results as follows: the EVMindex of7.17%,the PCDE of-35.66dB, the ACPR of-60dBc@(+/-5MHz)and-66dBc@(+/-10MHz).The DPD module improves ACPR for12dB,which meansan excellent linearity performance and can satisfy the linearity requirement of singlecarrier WCDMA repeater.