The modified multistage decoding scheme (MMDS) for a fast frequency-hoppedmultiple access MFSK system over a Rayleigh fading channel

The stage 3/2 decoding scheme, originally suggested by U. Timer [3], is mod ified for a Rayleigh fading channel to improve the performance of a fast fr equency-hopped multiple access/multilevel frequency shift keying system. Wh en signal-to-noise ratio per bit is 30 dB, the simulation results show that the modified stage 3/2 decoding scheme increases tile spectral efficiency by 11% compared to the modified stage 1 decoding scheme at bit error rate o f 10(-3). Further, the performance comparisons are made between the modifie d multistage decoding scheme and the diversity combining methods, where the modified stage 3/2 decoding scheme shows better performance.