On the delay performance of selective-repeat ARQ for underwater acoustic channels

摘要

There are few approaches for the delay analysis of ARQ in underwater acoustic links owing to the fact that only the worst efficient SW-ARQ can function over the half-duplex channel. Meanwhile, many approaches for the delay analysis of the most efficient SR-ARQ in terrestrial communications have appeared to be impractical because of the static channel assumption and/or much high computational complexity. In this paper, we first characterize the time-varying underwater acoustic channel by a two-state Markov model; then we perform SR-ARQ protocol based on the transmission scheme that is tailored for underwater acoustic channels and, in turn, analyze the mean delivery delay, which consists of transmission and resequencing delays. A closed-form expression of delivery delay whose computational complexity is insensitive to round-trip delay is derived. Both numerical and simulation results are finally provided to highlight the accuracy of the delivery delay analysis.