Performance of DS-CDMA over Multipath Fading Channel Using Rake Receivers for QAM

This paper access and reviews the work pertaining to reduction of Bit Error Rate (BER) over AW GN multipath fading channel using QAM. Further more quality improvement by bringing down the effectual bit error rate in the AWGN multipath fading channel is achieved. A high Signal to noise ratio indicate a reduced BER. The focus of this study is improvement of the performance of digital communication system. Low BER implies a reliable communication. A special type of receiver called “Rake receiver” consist of multiple correlators, it multiply the signal received, by a time shifted version of a known standard code sequence thus increasing the Signal to Noise Ratio (SNR) and decreasing the BER. For 16-QAM the BER performance of AWGN channel versus Rayleigh fading channel are compared and Gold Code is used as carrier for multipath fading using Rake receiver. The MATLAB simulation is done for different QAM versions. DS-CDMA system performance using 16 QAM for AWGN channel has been discussed.