A novel radio resource allocation scheme with delay considerations for OFDMA wireless networks

In this paper, we propose an adaptive cross-layer radio resource allocation (CL_ARRA) scheme, which is compatible with the IEEE 802.16e-2005 Orthogonal Frequency Division Multiple Access (OFDMA) air interface. The scheme comprises two steps: dynamic subcarrier allocation (DSA) and dynamic power allocation (DPA). Using DSA and DPA, we obtain a cross-layer function to maximize the system throughput and average delay performance under specific constraints. Unlike conventional methods that require different frequency resources for neighboring cells, our scheme allows overlapped cells to share the same frequency resource and reduces transmission collisions. In addition, our scheme incorporates a delay component to support real-time traffic. The performance of our scheme is validated by analytical and simulation results. It will be shown that CL_ARRA is superior to the proportional fair scheduler in 802.16e OFDMA because it takes into consideration of not only the channel state information but also the queue state information.