Improved multiuser detector for fast FH/MFSK systems with soft-limiter

In this paper, a modified multiuser detection scheme of the iterative interference cancellation (IIC) is proposed to reduce multiple access interference (MAI) in fast frequency hopping/multilevel frequency shift keying (FH/MFSK) systems. The proposed detector adopts diversity combining with soft-limiter in the IIC detector and simulation results show that the performance of the proposed detector can be improved significantly in a frequency-selective fading channel. The bit error rate (BER) of the proposed detector is about 2x to 10x smaller than that of the IIC detector for systems with frequency slots M=128, diversity order L=7, the number of users K=30 to 80, and the average bit energy-to-noise density ratio Eb/N0=25 dB