Sum-Power Minimization Problem in Multisource Single-AF-Relay Networks: A New Revisit to Study the Optimality

Abstract

For multisource single amplify-and-forward (AF) relay networks, the optimality of power allocation is revisited from different solution aspect, and a universal optimization framework is proposed. The proposed framework can be used to solve problems that have some common specific structure. As a baseline of the optimization framework, two theorems are proposed to obtain the extreme value of the problem, which is general to realize the optimal resource allocation under some system-specific constraints. Then, based on the proposed theorems, for multiuser single-AF-relay cooperative networks without direct links between sources and destinations, optimal power allocation strategies with low computational complexity are proposed to minimize sum-source-power consumption and sum-system-power consumption. When the number of mobile user is $n$ , the overall complexity of both power allocation schemes is $\mbox{O}(n)$ , which is lower than or same as the existing strategies. While comparing with the traditional methods to solve this type of problem, extensive numerical simulation has been conducted for different system setups to justify the effectiveness and efficacy of our proposed power allocation schemes.