Modulation and coding for short-duration deterministically time-varying channels

Discusses reliable data transmission from a low-orbit satellite to a geostationary satellite or ground station. In such scenarios, the received signal power increases as the transmitting low-orbit satellite comes into view, and then decreases as it then departs, resulting in a short-duration, time-varying communication link. The goal is to choose a modulation and coding scheme which maximizes the link throughput (in bits per contact) while satisfying a prescribed probability of error requirement. The authors assume M-ary PSK and a constant channel signaling rate R/sub s/, and determine optimal values for M and R/sub s/ using information-theoretic arguments. They then examine the throughput of both fixed rate and variable rate concatenated coding schemes for the channel that results from these optimal values.