Energy-Efficient Resource Allocation for Two-Way Multiple Relay OFDM System

Relay-assisted cooperative network coding systems are widely investigated as an effective framework to improve the system performance in IMT-Advanced system. On the other hand, green communication issues have been paid much attention due to the large energy consumption in wireless network. In this paper, an energy-efficient resource allocation scheme is proposed for two-way relay-assisted OFDM system with physical network coding. Considering subcarrier-pairing, subcarrier assignment to relay node and power allocation, the resource allocation scheme is formulated to minimize the total power consumption with the individual required QoS, which can further the system performance. The optimization problem is effectively solved by the dual approach and the computational complexity is analyzed. In order to reduce the computational complexity, two suboptimal algorithms are also proposed. Simulations are provided to demonstrate our theoretical analysis and the performance of the proposed optimal iterative algorithm.