Based on the eminent characteristics of opportunistic relaying cooperative communication system,this paper improves the conventional multi-relay ARQ (Automatic Repeat Request)cooperative diversity scheme,and optimizes the utility of wireless spectrum and energy by designing physical layer and data link layer jointly.The end-to-end performance analytical model using absorbing Markov chain is firstly proposed.With the application of this proposed analytical model,we analyze our improved opportunistic cooperative retransmission protocol’s performance parameters in terms of probability of end-to-end delivery success,probability of end-to-end delivery failure,delay,and throughput.Simulation results are finally provided to verify the correctness of our proposed analytical model,and the effects of the maximal retransmission times,channel fading parameters,and total transmission power on performance are discussed in detail.Our numerical results show that our improved opportunistic cooperative retransmission protocol has several desirable characteristics in energy saving and channel fading overcoming compared to other schemes,such as direct retransmission protocol and conventional multi-relay cooperative retransmission protocol.