Improving the throughput of a low-Earth orbit microsatellite protocol

This paper proposes an approach to improve the throughput of the uncoded protocol in use by some UoSAT/SSTL microsatellites, i.e., the hole-filling PACSAT broadcast automatic retransmission request (PB-ARQ). The goal is achieved by adaptively incorporating a forward error correction (FEC) capability. Analyses on the design constraints lead to the implementation of a punctured convolutional code with code-combining Viterbi decoding. Simulations show that the propose scheme outperforms the existing one in all simulated possible channel bit error rates (BERs). The formerly zero throughput at channel BER around 5/spl times/10/sup -3/ is now increased to approximately 60%.