Cooperative Networks With Limited Feedback

In this paper, we propose a limited feedback scheme to minimize the outage probability for a wireless cooperative decode-and-forward network. Specifically, based on the instantaneous conditions of the source-destination and relay-destination channels, the destination will allocate the transmission time of the source and relay and feed back the allocation results to the source. Both full, or infinite-rate, feedback and limited feedback are considered. To simplify the expression of the outage probability in the full feedback case, a lower bound is proposed, based on which we find the sub-optimal location of the relay that can result in a close-to-optimal outage performance. Our results show that, even with only one-bit feedback, a significant improvement in terms of the outage probability can be achieved compared to the no feedback case. Furthermore, the outage performance can approach optimality by exploiting only two or three bits feedback from the destination.