Date Added: Apr 2011
This paper studies the long-term throughput performance of repetition protocols coupled with power control for multiple access block-fading channels where the feedback bits are used to inform the transmitter about the decoding status and the instantaneous channel quality. The throughput of simple and practically inspired protocols is determined. Remarkable throughput improvements, especially at low and moderate SNR, is demonstrated compared to protocols where the feedback bits are used for acknowledgment only or for power control only. Numerical results for symmetric Rayleigh fading channels show that the throughput improvement is mainly due to the ability to perform a power control, rather than to retransmit.