CAPACITY OF AN FH-SSMA SYSTEM IN DIFFERENT FADING ENVIRONMENTS

In this paper, the capacity of a previously proposed frequency-hopped spread-spectrum multiple-access system (FH-SSMA) is evaluated under th ree types of fading, namely, Rician, shadowed Rician, and Nakagami fad ing, The results of recent experiments have indicated that these fadin g phenomena occur in various environments, where the FH-SSMA system ma y be implemented, This paper presents the derivation of the deletion p robability for each type of fading and analyzes the system capacity in ,terms of the maximum number of users versus the average bit-error rat e (BER), The effect of a change in the signal-to-noise ratio (SNR) lev el on the system capacity is also demonstrated, For Rician fading, we find that the capacity of the system with a Rician factor of 2 dB is r educed by 13% as compared to the capacity for the nonfading case, For shadowed Rician fading, three shadowing scenarios are considered: ligh t, average, and heavy, It is shown that the light and average shadowin g scenarios provide only a slight decrease in the capacity, while the heavy shadowing scenario renders a capacity identical to that for the Rayleigh fading case, Finally, for Nakagami fading, the capacity is fo und to decrease by 50% as the fading parameter is reduced to 0.5.