Power Allocation Framework for OFDMA-based Relay-Enhanced Cellular Networks

In this paper, a framework for power allocation is presented for downlink transmissions in an OFDMA-based cellular relay network. We consider a system with a single base station communicating with multiple users assisted by multiple relays. The relays have limited power which must be divided among the users they support in order to maximize the data rate of the whole network. By finding the optimal power requirement of each user, and based on knapsack problem the optimal power allocation which maximizes the data rate is proposed as an upper bound. Another power allocation scheme, weighted-based scheme, is proposed considering the fairness issue. Finally, to utilize the power wisely and improve the data rate of the network, an efficient power reallocation scheme is proposed. Simulation results demonstrate the efficacy of the proposed schemes.