BER performance analysis of M-ary modulation techniques in an outdoor environment with MLSE equalizer over fading channels

Abstract

In this paper, we consider a communication system that uses M-ary phase shift keying (MPSK), M-ary quadrature amplitude modulation (MQAM), M-ary differential phase shift keying (MDPSK) and M-ary pulse amplitude modulation (MPAM) to transmit information over a Rayleigh and Ricean fading channel perturbed by additive white Gaussian noise (AWGN). We model the fading channel using Jakes Doppler power spectrum and AJakes Doppler power spectrum. The performance of these different modulation techniques is analyzed in terms of bit error rate (BER) for single and multipath Rayleigh fading channel in outdoor environment by MATLAB simulation. For the simulation of fading channel the different property values e.g. path delays, average path gains, maximum Doppler shifts, Doppler spectrum parameters etc are chosen properly to a reflect realistic fading channels. In all the cases, our analysis shows that MQAM performs better and the system performance increases with the use of maximum likelihood sequence estimation (MLSE) equalizer over Rayleigh and Ricean Fading channels.