Digital audio broadcasting (DAB) over non-stationary satellite systems

Non-stationary broadcast (BC) satellite systems can provide a continuous, direct-to-user, and worldwide BC service. Owing to the improved radio link margin of LEO/MEO systems, one can overcome the problems of blockage and foliage attenuation, which are significant in the alternative GEO/HEO systems. A basic analysis also reveals that the specifications of the standardized ITU A (EUREKA 147) DAB signal are adequate to cope with range and range rate effects due to the satellite motion. It is shown that a continuous, area-wide high-quality BC service can be provided by overlapping cellular service areas. Each cell may have an individual uplink station for feeding the BC signal. A system concept is discussed which is based on the exploitation of range, range rate, and angular information onboard the satellites with respect to each individual uplink station in order to compensate for Doppler frequency shifts and for variable signal propagation delay. Copyright (C) 2000 John Wiley & Sons, Ltd.