On Cooperative Strategies in Wireless Relay Networks

In this paper, we study the cooperative strategies of relay stations in wireless relay networks. As pure relay stations distributed across the network and centrally controlled by the base station can be exploited to form cooperative antenna arrays, we determine which relay stations should cooperate with one another such that the performance of wireless relay networks can be optimized. Specifically, we define and formulate the throughput maximization problem for wireless relay networks under practical model of relay station cooperation. We design an iterative search algorithm to solve the relay station cooperation problem. The proposed algorithm is proved via simulations to yield near-optimal solutions with only linear-time complexity. The simulation results also show that cooperative transmissions of relay station can significantly improve system throughput and reduce the handover probability of mobile stations. More importantly, the placement of relay stations is crucial to the throughput gain obtained by relay station cooperation.