Outage-Constrained Source-Sum-Power Minimization in Multiple-Sensor Single-DF-Relay Networks

This letter provides an optimal power allocation that minimizes source-sum-power consumption under outage constraints in a wireless multiple-sensor single-relay network. We consider decode-and-forward (DF) relaying and assume that direct-link communication does not exist. We provide an exact expression of an optimal power allocation by using Karush-Kuhn-Tucker (KKT) conditions. Constructive details used in finding the optimal power allocation as well as numerical investigation is given to verify the optimality of the proposed solution. Numerical results also show that the proposed power allocation reduces the source-sum-power consumption by nearly 34-69% compared to a non-optimal allocation. The power saving depends on the number of sources and becomes large when the number increases.