Frequency-hopped multiple-access communication with nonorthogonal BFSK in Rayleigh fading channels

A nonorthogonal binary frequency-shift keying is considered in frequency-hopped multiple-access communication systems with Reed–Solomon coding. The effect of tone spacing on the average number of successfully transmitted information bits per unit time per unit bandwidth (called normalized throughput) is examined in Rayleigh fading channels. The tradeoff among tone spacing, code rate, and number of frequency slots in maximizing the normalized throughput is examined, keeping the total bandwidth fixed. The optimal tone spacing, code rate, and number of frequency slots in terms of the number of users and Eb=N0 is also discussed. The throughput gain attained by using the optimal tone spacing becomes more significant as the number of users is increased.