Hybrid SR ARQ Scheme Using Trellis Coded Modulation for Point-To-Multipoint Communication Over Nonstationary Channels

Authors: NECMİ TAŞPINAR

Abstract: In this paper, a type-I hybrid SR ARQ scheme using trellis coded modulation (TCM) for point-to-multipoint communication was analyzed on nonstationary broadcast channels where the channel bit error rate (BER) varies over time. A nonstationary channel is modelled as a two-state Markov chain. In the numerical calculations, it is found that, for a given p_{1} and \bar \varepsilon , the values of the average burst length \bar b have a very small influence on the throughput. Numerical results show that the throughput is better for values between 10 ^{-6} and 10 ^{-4}of average bit error rate \bar \varepsilon if the errors occur in bursts. However, the scheme performs better for the stationary channel when the average bit error rate becomes large. For medium and high values of \bar \varepsilon , the throughput decreases when the number of receivers increases.

Keywords: Data transmission, multicast ARQ, nonstationary channel, throughput efficiency.

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