SOFT-DECISION VITERBI DECODING WITH DIVERSITY COMBINING FOR MULTIBEAMMOBILE SATELLITE COMMUNICATION-SYSTEMS

Diversity combining methods for mobile satellite communication systems employing convolutional encoding and soft-decision Viterbi decoding a re evaluated. Computer simulation clarifies that the pre-Viterbi-decod ing maximal ratio combining method has better performance than other m ethods in Rician fading channels. The simulation results agree with th e Pe (bit error probability) performance derived from the numerical an alysis for slow fading using the approximate Pe performance of Viterbi decoding in AWGN (additive white Gaussian noise) channels and the pro bability density function of Rician fading. Applying this diversity me thod to the multi-beam mobile satellite communication systems, a satel lite beam diversity reception scheme is proposed. A computer simulatio n result shows that the proposed scheme decreases the packet error rat e of the control signals to less than 1/100 around the satellite beam boundary.