Abstract: The paper presents throughput analysis results obtained by analyzing the application of Selective repeat, and Go-back-N protocols, to data transmission over an HF radio channel in a real communication system with a practical goal to attain optimal system utilization by maximizing system throughput in the presence of fading. An expression for the optimal information block length has been derived. The communication system is based on a multitone modem. The analysis has been performed for a channel with additive Gaussian noise and a Rayleigh fading channel. System throughput has been analyzed for 75-3600 b/s parallel data modem, for M-ary DPSK modulation schemes, without coding and with Reed- Solomon (6,4) and Golay (24,12) error correction coding, with several levels of in-band diversity.
Key words: Data transmission, selective repeat protocol, HF radio, DPSK.