Optimal Subcarrier-Chunk Scheduling for OFDM Systems

In practical orthogonal frequency division multiplexing (OFDM) systems, subcarriers are grouped into chunks and a chunk of subcarriers is regarded as the minimum unit for subcarrier allocation. We consider the optimal chunk assignment that maximizes a utility function of average user rates for a wireless OFDM system under different power control policies. It is shown that the optimal schemes adopt a greedy structure. Novel low-complexity algorithms are developed to approach the optimal strategies without a-priori knowledge of statistics of the intended wireless channels. Numerical results are provided to gauge the performance of the proposed schemes.