Joint source and relay power optimization in multiuser cooperative wireless networks

This paper considers the minimization of overall power transmitted from source and relay nodes in a multiuser cooperative network, constrained with the quality of service (QoS) of each user determined by their output signal-to-interference-plus-noise ratio (SINR). In this paper, we consider a two-hop cooperative wireless network consisting of single-antenna nodes in which multiple concurrent links are relayed by a number of cooperative nodes. Unlike the previous relevant works that either consider the source power or relay weight optimization or their joint optimization in a separate sense, this paper considers them in the same platform and thus achieves overall transmit power minimization. It is shown that optimized power distribution over the source and relay nodes depends on the channel conditions and thus requires joint optimization operation as proposed in this paper. Compared to the previously developed schemes, the joint power optimization developed in this paper offers significant transmit power reduction and QoS satisfactions.