Diversity Improvement in Frequency-Hopping Multilevel FSK Systems Under the Influence of Rayleigh Fading and Log-Normal Shadowing

Recently, various frequency-hopping schemes have been proposed for possible application to digital mobile radio telephony. While the advantage of the inherent frequency diversity against fading is well known, the improvement in the system performance due to the use of space diversity has not been studied. In this paper we analyze the performance of FH-MFSK under the influence of Rayleigh fading and log-normal shadowing due to the combined use of frequency and space diversities. It is shown by analysis that the system capacity can be increased from the corresponding nondiversity figure by 26.3 percent relative to the full system capacity (i.e., 209 users) with the use of two diversity branches at channel condition of 10 dB normalized area mean and worst case of shadowing dB. Also, graphical results are given for different channel environments, and required signal-to-noise ratio.