Performance of BFSK FHMA systems with RTT side information over fading channels

The performance of frequency-hopping multiple-access systems with side information and binary frequency-shift keying signaling is evaluated. The side information is generated by Viterbi's ratio threshold test (RTT). Both synchronous and asynchronous hopping systems over fading channels are examined. The system with RTT side information performs significantly better than that with perfect side information or hard decision. Compared with hard decision, the RTT side information provides more than 20% improvement in capacity for E/sub b//N/sub 0/=10 dB over Rayleigh channels. Also, we find that the optimum threshold in the RTT scheme should be dynamically adjusted with the number of simultaneous users in the system.