COMPARATIVE ANALYSIS OF M-QAM SIGNALINGS SCHEMES PERFORMANCE OVER FAST AND FREQUENCY NON-SELECTIVE RAYLEIGH FADING CHANNEL WITH MRC RECEIVER

This paper presents a comparative analysis of some digital modulation signaling schemes over fast and frequency non selective Rayleigh fading channel with multiplicative distortion, addictive white Gaussian Noise (AWGN) and maximal ratio combining (MRC) at the receiver. Three M-ary (with m=4, 8, 16) modulation schemes are used as the channel input and a comparative analysis is carried out in terms of bit error rate (BER) averaged over the iterations (ABER) versus the signal-to-noise ratio(SNR) for different orders of the M-ary over the channel and the processing of the received signal by an MRC were simulated using MATLAB 7.0 application package. The result show that, of the three modulation schemes considered, the ABER performance for 4. Level quadrature amplitude modulated (QAM) signal is the best followed by that for 8QAM, while an excessive degradation is noticeable in the ABER performance of the 16QAM scheme when compared with the performances of the other two schemes even when an MRC receiver is used