Simulation techniques for mobile satellite channel

To evaluate the system performance for mobile satellite communications, it is necessary to take into account the effects of channel impairments by quantitative simulations. Although multipath fading is less destructive to signal propagation than in the case of land mobile radio, channel characterization is still of interest to system planners and designers. The research reported in the paper has resulted in the development of a Markov 3-state stochastic channel model that is useful in testing various digital modulation, channel coding, and receiver diversity designs. A mathematical algorithm is used to generate the Rayleigh fading, Rician fading, and log-normal fading signals which are subsequently used to realize the proposed channel model in cooperation with a linear combination of probabilities of state occurrence and state transition. This developed channel model has been successfully implemented in a TMS320C30 microprocessor to provide a real-time simulation capability. The bit-error-rate (BER) performance of π/4DQPSK modulation, with I/Q coherent detection has been tested using the system