M-QAM Communication System Over a Multipath Fading Channel with Delay Spread

Abstract

Multipath performance is an important and practical consideration for communication systems. In this paper the performance of the
M-QAM communication system over a six-ray independent multipath fading channel is evaluated by computer simulations. The low-pass
equivalent model of the M-QAM system is considered. Based on this model, the effects of system parameters on the bit-error (BER)
performance are analyzed. The spread delays, Doppler spread frequency and the attenuation of each ray (path) are the parameters of the
simulation. Effect of bit duration on the BER performance of M-QAM system is also analyzed. BER of 10-3 was found even at higher
Doppler spread frequency and in deep fade scenario and also it is seen that bit-error rate decreases with the increasing data transmission rate.