An adaptive selective repeat ARQ scheme under Rayleigh fading channel

An adaptive selective automatic repeat request scheme under Rayleigh fading channel is proposed, which adjusts the transmission modes such as packet sizes according to the channel state variation. Multi-state Markov system model is generated after the channel variation state and the transmission mode are united. Closed form expressions of throughput efficiency of ideal and non-ideal adaptive selective repeat automatic repeat request (ARQ) are derived. Furthermore, system parameters of non-ideal adaptive selective repeat ARQ are optimized based on ideal adaptive selective ARQ state transition graph. Simulation results verify that the throughput efficiency of non-ideal adaptive selective ARQ with optimum system parameters is nearly equal to that of ideal adaptive selective ARQ and better than that of non-ideal adaptive selective ARQ without optimum system parameters in a wide range of signal to noise ratio.