Minimum outage probability routing and power allocation in wireless ad-hoc networks

We address the minimum outage probability problem for unicast communication in quasistatic networks when total power consumption is constrained. We use relay-channel signaling rather than traditional multihop routing. Under the assumptions that carrier level synchronization is not available and every intermediate node uses a decode-forward scheme, we show that for any node the interference from other unintended transmissions is effectively cancelled out even if all communications share one common physical medium. We show that any optimal relaying structure can be converted to a sequential path, for which we find a simple optimal power-allocation policy. Finding an optimal sequential path is still complex, and we therefore present two polynomial heuristic algorithms. Our simulation results show that they achieve exceptional outage performance and can obtain gains up to 4.5 dB and 6 dB respectively for outage probability 10/sup -3/.