Joint Channel- and Queue-Aware Scheduling for Multiuser Diversity in Wireless OFDMA Networks

In this paper, packet scheduling in an orthogonal frequency division multiplex access downlink is investigated based on cross-layer design and optimization. We first develop max-delay-utility scheduling with the help of channel and queue state information to exploit multiuser diversity and guarantee quality of service. The stability property of a scheduling policy is characterized by the stability region, which is the largest region on arrival rates for which the queueing system can be stabilized by the scheduling policy. It is shown in this paper that under very loose conditions, the max-delay-utility scheduling has the maximum stability region. In environments with insufficient scattering or strong line-of-sight components, delay transmit diversity can increase the fluctuation in the frequency domain to improve the performance. The simulation results show that the max-delay-utility scheduling with a frugality constraint is highly advantageous to data transmission with a low latency requirement over shared multiple channels, and that joint scheduling and power allocation can substantially boost the performance.