Optimal Partner Selection Strategies in Wireless Cooperative Networks with Fixed and Variable Transmit Power

Cooperative communication has emerged as a promising technique to enhance system reliability and performances in resource-limited wireless networks. Before any kind of cooperation ever starts, nodes in the network have to find someone to cooperate with and the helping node is so called partner. This paper concerns about the partner selection problem in centralized networks, where an AP assigns partner for each node and schedules all the transmission. Three optimal partner selection strategies with different aims are proposed and analyzed under fixed and variable transmit power respectively. They are the maximum total utility (MTU) strategy, the maximum minimum utility (MMU) strategy and the maximum product utility (MPU) strategy. Simulation results show that with variable transmit power, both system-level efficiency and node-level fairness can be greatly improved, and the three strategies successfully achieve their goals respectively.