Simulation Model for a Frequency-Selective Land Mobile Satellite Communication Channel

This paper investigates a three-state simulation model for a frequency-selective land mobile satellite communication (LMSC) channel. Aside from ionospheric effects, the propagation channels for LMSC systems are also characterized by wideband effects due to multipath fading which makes the channels time-variant and exhibit frequency-selective distortion. Hence, an adequate knowledge and modelling of the propagation channel is necessary for the design and performance evaluation of the LMSC systems. A three-state simulation model for a frequency-selective LMSC channel, which is a combination of Rayleigh, Rician and Loo fading processes, is developed. The propagation characteristics of the proposed LMSC channel model are presented, and comparisons are made with the Rayleigh, Rician and Loo fading channels using bit error rate (BER) as the figure of merit. The simulation results show that the degree of fading experienced by the LMSC link depends on the length of time the mobile terminal is in a particular state or location, depending on the assumed probability of occurrence of each fading process; and it is observed from the BER results that the propagation impairment of the LMSC fading channel is relatively lower than that of Rayleigh and Loo fading channels but higher than the Rician fading channel. Keywords: mobile, multipath fading, propagation channel, satellite communication, wideband.