Resource Allocation Techniques for OFDMA-Based Decode-and-Forward Relaying Networks

In this paper, we focus on the design of efficient resource allocation algorithms for a multihop cellular network, with orthogonal frequency division multiple access (OFDMA) as downlink transmission technique and utilizing decode-and- forward cooperation strategy. Our objective is to maximize the total capacity based on the constraint of individual transmission power at each transmitter. We also consider users´ QoS requirements by maximizing the total capacity while giving users proportional fairness weights according to their data requirements. We show that for each data symbol (at each subcarrier) transmitted by base station, the best relaying strategy is to let only one among all the relay stations perform the relaying task. This is true for both objectives of maximizing total capacity and maximizing capacity with proportional fairness constraint. We then propose efficient greedy algorithms for both centralized and distributed resource allocations based on our analysis. Simulation results indicate that our proposed algorithms effectively enhance the total capacity.