Performance enhancement of relay-assisted communications via binary feedback

This paper proposes a modified two-hop wireless communication system and studies its performance. The modified system has a reliable feedback channel that carries a binary signal from the receiver to inform the transmitter about the current state of the channel, and hence affects transmission decision. In the analysis, both regenerative and nonregenerative systems are considered. Outage probability, which is the probability of having the link quality below a certain threshold is used as the performance assessment tool. Numerical results show that binary feedback greatly improves the performance of two-hop systems, specially when the transmission threshold is set close to the outage threshold. They also show that non-regenerative systems with binary feedback can outperform regenerative systems without any feedback.