Channel Estimation And AGC Technology And Its Implementation In OFDM Systems

In today’s society, the requirement for wireless communication service quality isbecoming more and more high. The phenomenon promotes the innovation of mobilecommunication from current generation to the next one. So far, the3GPP organizationraise The long term evolution (LTE) project to further improve the system datatransmission rate and the utilization of frequency,To reduce the system delay,andincrease system coverage and channel capacity. The project is the evolution of3Gtechnology, at the same time also compatible to3G.LTE use OFDM technology as a keytechnology,and achieve in the future wireless communication performance requirements.This project is the cooperation project of CETC.The primary mission is to refer to thestandard of LTE, and to accomplish a new generation of wireless communication systemphysical layer using FPGA platform. This work is mainly reflected in two aspects:The Channel estimation and equalization module is indispensable for OFDMsystem. A improved algorithm for LS algorithm is put in the article in order to improvethe performance of channel estimation module.In this thesis,we finish the structures ofthe wireless communication system based on OFDM technology in Matlab,make acomparison on BER curve between DCT_LS algorithm and LS algorithm,and realizethe the channel estimatior and equalizatior using FPGA.In terms of implementation,wewrote the RTL code,bring out the point of adaptive threshold.according to the power ofproject frame’s ups and downs.Moreover,we verify the correctness of the module byModelsim.Finally,we make the board level verification and analysis by Chipscope.The other important point is to finish the key module of the communication systemwhich is called Auto Gain Control module (AGC).Usually,AGC module is divided intwo parts which are external AGC and internal AGC.In spect of the control words’shock in external AGC,we put forward a counter-delayed program,which will make thesystem more stable.In spect of the problem of slow convergence in internal AGC,wepropose a two-factor convergence program.In this thesis,we accomplish the overallframework, the theoretical simulation and FPGA implementation of the AGC module.The module is verified by modelsim6.5and board debugging.At last,we can achieve a wireless mobile communication within a certain distance.