A Study For Rake Receiver In Wireless Spread-Spectrum Communication System

CAMA is becoming main stream in 3G mobile communication system,and wireless communication system are expected to provide ubiquitous, high-quality, and high-rate mobile multimedia transmission. Direct spread spectrum is one of the most competitive technologies in the future mobile communication.In order to realize the no-error high-data wireless transmission, many key technologies need to be studied.This dissertation foucuses on the spead spectrum, channel estimation and Rake receiver of the mobile communication system.Firstly, this dissertation analyzes the kye technologies in this wireless DS-SS.Considering the characteristics of this system with short distance and good environment, a useful scheme is obtained by simplifying the algorithm.Additionally, The Channel Estimation in DS-SS system is also studied in this dissertation. Several simple channel estimation methods are presented and their performances are compared. Moreover, simulations of channel estimation in different channel conditions are carried out. The performances of the channel estimation based on polit are shown finally.RAKE receiving is essential in DS-SS system, ant it improves the performance of the receiver. Based on the mathematic module of the radio channel, the principle of the RAKE receiving is given, and a structure of the Rake receiver in DS-SS system is presented. Then performances of the RAKE receiver with different parameters are compared, and an optimized RAKE receiver structure is determined.The last part of this thesis introduces the hardware implementation of base-station receiver in DS-SS system. All the designs are developed with Verilog HDL and design are fully verified on FPGA platform.