Opportunistic relaying in multiuser cooperative networks with proportional rate constraints

Cooperative communication is an efficient solution to combat wireless channel fading and to increase system throughput in future board communication. In this paper, we consider the uplink scenario of multi-user cooperative network, in which the resource is allocated to the users with the consideration of both fairness guarantee and throughput enhancement. The system uplink throughput is optimized by using decode-and-forward (DF) opportunistic relaying. We show that the optimization problem is formulated as a mixed binary integer programming problem, which is hard to find the global optimum in terms of computational complexity. Thus we decomposed the optimization problem into two sub-problems of opportunistic relaying strategy and power allocation. First, the opportunistic relaying strategy is given by making use of the equivalent channel power gain. Second, a low-complexity power allocation scheme is proposed. The simulation result shows that the proposed scheme can both improve the system throughput and ensure the fairness.