On the throughput of ARQ over multiple-access relay fading channels with queueing constraints

In this paper, the throughput under queuing constraints in multiple-access relay fading channels achieved by fixed-rate transmissions and a simple automatic repeat request (ARQ) protocol is investigated in the absence of channel side information (CSI) at the transmitters. Transmission is considered to be either in the ON or OFF state, depending on the reliability of the reception, and retransmissions are triggered by the ARQ protocol in the OFF state. The probabilities of these transmission states are identified. Through stability and queuing analysis, feasible set of system parameters is determined, and the maximum constant arrival rates at source nodes, which can be supported by the system under queuing constraints, are characterized in terms of the fixed transmission rates, state probabilities, and quality of service parameters.