Joint Packet Scheduling and Subcarrier Assignment for Video Communications Over Downlink OFDMA Systems

This paper investigates the joint optimization of multiuser packet scheduling and wireless resource allocation for video communications over downlink orthogonal frequency-division multiple-access (OFDMA) systems. The objective is to maximize the expected video quality of all mobile users under the wireless resource and delay-bound constraints. We formulate a quality-driven cross-layer problem to jointly optimize the packet scheduling and subcarrier assignment. Using a dual approach, an asymptotically optimal solution is derived to efficiently solve the problem. Furthermore, we propose a suboptimal algorithm to reduce the computational complexity such that the requirements of real-time video applications can be satisfied. Finally, the computational complexity of the algorithms is analyzed, and numerical simulations are carried out to evaluate the performance of the proposed algorithms.