Performance of a FH/MFSK System with Aldaptive Thresholds over a Rayleigh Fading Channel

In this paper, a frequency-hopped/multilevel frequency shift keying (FH/MFSK) system with adaptive thresholds is proposed for a Rayleigh fading channel. The adaptive thresholds are determined by averaging the signal level of output from the envelope detector for eaich M-ary symbol. Low threshold for a row gives high detection probability, when the average output of the envelope detector is high. High threshold for a row gives low false alarm probability, when the average output of the envelope detector is low. The simulation results show that the FH/MFSK system with adaptive thresholds achieves lower bit error probability than the system with fixed thresholds. I