Bit-error rate simulation and analysis of various frequency-hopped multiple-access receivers

Abstract

In the 21st century, with the large-scale development of mobile communication network, users put forward higher requirements for the excellent performance of the system, and FHSS system has been proposed and widely applied in military nowadays. FHSS system has good performance in anti-interference and high security in message transmission. In this dissertation, we mainly focus on the fast FHSS system modulated in BFSK. The fading channel, diversity combination and MAI at the receiver are three factors we study that have influence on the performance of the whole system. We simulate the spread sequence transmitting in AWGN channel, Rayleigh fading channel and Rician fading channel separately and in each channel, we use 3 different combination methods: MRC, EGC and SC to receive the signal. The MAI factor is also considered. After receiving the signal, we compare the BER performance in the case of 1 user, 5 users and 10 users to find how multi-users affect the system. In the end, we get the results of BER performances in different situations. In each channel, we have 3 figures illustrating the BER performance of MRC, EGC and SC with multiple users. The results show that MRC performs the best and SC is the worst; Rayleigh fading channel and Rician fading channel both can degrade the BER of the system while Rician channel performs better than Rayleigh channel; the MAI does have bad effects at the receiver and degrades the BER performance significantly.