Application of coding and diversity to UHF satellite soundbroadcasting systems

Results are presented of a study of alternative means by which to reduce the required link margins in a satellite sound broadcasting system, thus improving the economic feasibility of the service and increasing the possibility of sharing a radio-frequency allocation with terrestrial services. Propagation models are presented that account for the effects of shadowing and multipath in the operating environments. Comparisons are made of the performance that results using time, frequency, and space diversity to moderate the effects of shadowing and multipath for vehicular and portable receivers. It is shown that space diversity has the broadest applicability in restoring the channel performance that would otherwise be degraded by Rayleigh fading channels and by quasistationary AWGN (additive white Gaussian noise) channels. Example link budgets are given for candidate satellite sound broadcasting system designs that use analog FM and digital modulation techniques