无线环境下失真和时限感知的视频分组调度机制  

Distortion and Deadline Aware Packet Scheduling for Video Streaming over Wireless

作　　者：李志鹏[1] 卢汉成[1] 洪佩琳[1] 

机构地区：[1]中国科学技术大学电子工程与信息科学系,合肥230027

出　　处：《电子与信息学报》2013年第9期2213-2219,共7页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(60832005;61170231)资助课题

摘　　要：现有无线分组调度算法一般以最大化系统吞吐量或者保证用户之间公平性为目标。然而,不同视频分组之间存在着重要性差异,使得传统的内容无关调度算法不适用于无线视频传输。充分发掘视频分组之间存在的重要性差异并准确衡量视频分组的传输失真,能够在资源受限的无线环境下更合理地分配资源,提高视频传输质量。该文首先提出一种分组级别视频传输失真衡量模型,用于预测视频分组丢失对视频质量的影响,然后考虑分组时限的影响,提出分组级别的时限扩展模型。在此基础上,利用正交频分复用(OFDM)技术在无线资源(时域、频域及功率)分配上的灵活性,提出一种基于梯度的失真和时限感知调度算法。仿真结果表明该文所提出的调度算法相对于传统内容无关算法最大有4.3 dB的平均峰值信噪比(PSNR)增益。Most of current wireless packet scheduling algorithms aim at maximizing overall system throughput or achieving a certain type of fairness among mobile users. However, these content-independent algorithms can not be applied to wireless video transmission because different video packets have different levels of contribution to the overall video quality at the receiver side. Fully exploring the differences between the video packets and accurate predicting the transmission distortion caused by lost video packets can significantly improve the performance of video streaming over resource-constrained wireless networks. In this paper, a packet-level transmission distortion model is proposed to predict the quality degradation of decoded videos by lost video packets, the packet-level deadline is defined to extend the model. Based on this packet-level transmission distortion model and packet-level deadline extended model, a gradient-based distortion and deadline aware scheduling algorithm is proposed, which prioritizes the transmissions of different users by considering distortion impact, deadline requirements and fully exploit the flexibility of resource allocation provided by the Orthogonal Frequency Division Multiplexing （OFDM） technology in terms of time, frequency and power. The experimental results demonstrate that the proposed algorithm outperforms the content-independent algorithms with a gain of as much as 4.3 dB in terms of average Peak Signal-to-Noise Ratio （PSNR）.

关 键 词：无线分组调度 视频流 资源分配 时限 

分 类 号：TN919.85[电子电信—通信与信息系统]