Cross-layer optimization with guaranteed QoS for wireless multiuser OFDM systems

We propose a novel cross-layer optimization scheme for the downlink multiuser orthogonal frequency division multiplexing (OFDM) system. The proposed maximum weighted capacity (MWC) based resource allocation at the physical (PHY) layer can provide a much better QoS than the previous resource allocation schemes, while maintaining the highest or nearly highest capacity and costing a similar complexity. In particular, the more fluctuation in different users' data arrival rates, the more advantages of MWC in both QoS and capacity. Besides, our proposed delay satisfaction (DS) scheduling at the medium access control (MAC) layer allows more than one connection to be served in each slot, which is more efficient than conventional scheduling.