Joint optimization of power allocation and cooperation in wireless OFDM networks

In wireless communication networks more than one antenna can be used to enhance the quality of transmission with transmit diversity. However, wireless devices such as mobile phones cannot have more than one antenna because of limits on size and complexity. Recently, cooperative communications have been proposed to create virtual antenna systems for circumventing this problem. This technique achieves a diversity gain by using a combination of the relayed signal and the direct signal. Here, we use a dual optimization method for non-convex problems to jointly optimize the power allocation and the scheduling of wireless cooperative OFDM systems. We find the optimal solution, and confirm our analysis by numerical results.