Diversity combining for M-ary fast frequency hopping multiple-access Rayleigh fading channel

This paper investigates four diversity combining techniques for a fast frequency hopped spread-spectrum multiple-access (FFH/SSMA) communications system. A single cell system is considered with multiple-access interference, additive white Gaussian noise and Rayleigh fading. The modulation is M-ary frequency shift keying with non-coherent detection at the receiver. The system performance is evaluated for a fixed bandwidth and various values of M and diversity. The order statistics-normalized envelope detection technique is shown to be the best of the methods considered, and its spectral efficiency is presented. A land mobile communication system is considered.