A wireless video streaming system based on OFDMA with multi-layer H.264 coding and adaptive radio resource allocation

摘要

With the advancement of video-compression technology and the wide deployment of wireless networks, there is an increasing demand for wireless video communication services, and many design challenges remain to be overcome. In this work, an adaptive framework is proposed and simulated for multi-user video transmission over OFDMA-based communication system for the efficient streaming of multi-layered H.264 video over wireless channels. The aim of the proposed method is to combine adaptive sub-carrier allocation and bit loading with the transmission of the H.264 SVC(Scalable Video Coding ) encoded video sequences in order to increase the number of supported users in the system and provide the best quality of service(QoS) to the sub-carriers. The scalable extension H.264/MPEG4-AVC video codec is used to obtain two different bitstreams: a base-layer (carrying the most critical information content at low bitrate), and an enhancement layer, characterized by increasing bitrate and decreasing importance of video content. A prior study of the video quality is performed with a theoretical model, as the quality of the received video will depend on the errors introduced by the wireless channel. The required BER is depends on the video quality, which is the most crucial parameter to determine. The bandwidth is distributed among the orthogonal sub-carriers and the best suited sub-carriers is given to the base layers to achieve the required BER. The paper proposes an overview of the system and tests its performance through extensive simulations. The proposed framework significantly improves the video transmission quality with the maximum use of radio resources.