Quality-Driven Cross-Layer Design for H.264/AVC Video Transmission over OFDMA System

Video applications over wireless network have attracted more and more attention in recent years. However, due to the unique characteristics of video, limited available resources and the time-varying wireless channel state, video transmission over wireless network is still a challenging task. In this paper, a novel cross-layer design is proposed to maximize the overall received video quality with the limited network resource and the stringent deadline constraints over OFDMA network. Considering the information extracted from the Application layer, Media Access Control layer and Physical layer, we formulate the packet scheduling, subcarrier assignment and power allocation into a mathematical model. By employing Lagrange dual decomposition, asymptotically optimal packet scheduling and resource allocation strategy can be obtained. To reduce the computation complexity, we further develop a suboptimal solution which performs packet scheduling and subcarrier assignment jointly but power optimization independently. Finally, we validate our proposed algorithms in a multi-user scenario where all the video sequences are pre-encoded by H.264/AVC encoder. Experimental results demonstrate that our proposed algorithms can indeed improve the received video quality significantly compared with other existing algorithms.