Simple Analysis of BER Performance for BPSK and MQAM Over Fading Channel

Abstract

In communication systems during convey messages through wireless channels many factors may effect quality of the messages. Multipath fading, interference and signals phase shift playing crucial roles in deterioration conveying signals. Bit Error Rate (BER) is one of the key metrics which employing to assess quality of such traveling signals. So, this paper is conducted to analyze influence of different factors on the BER with considering effect of multipath fading. Multipath is the propagation phenomenon that results in radio signals' reaching the receiving antenna by two or more paths. The effects of multipath include constructive and destructive interference, and phase shifting of the signal. This distortion of signals caused by multipath is known as fading. Fading causes fluctuations in the attenuation of the signals as traveling along the medium. There are many fading models for the distribution of the attenuation, in this paper Rayleigh fading channel is considered. BER performance for BPSK and MQAM signals over AWGN and Rayleigh fading channels are investigated and analyzed with Matlab. The achieved results show that as the modulation order increases bit error rate also increases, and the BER for BPSK and MQAM over an AWGN channel is less than that obtained with conveying the signals over Rayleigh channel for certain values of signal to noise ratio.