A Framework for Efficient Wireless Video Communication: Dynamic Source/Channel Adaptation and Distortion Evaluation

西北大学对支持无线网络上的视频通信有很大的兴趣。这并不是一项简单的任务，因为视频应用程序要求严格的服务质量(Qos)，而且无线通道存在许多缺陷。视频的两个重要的服务质量特征是信号失真程度和传输延迟。无线信道是有损耗的，具有时变响应，并且容易受到多用户干扰。此外，由于无线网络的用户是移动的，因此利用可用能量是一个关键的考虑因素。无线视频中固有的缺陷可以在物理层和资源编码层两者中解决。我们在一个跨层的框架中共同考虑这些方法的组合，具体地，我们考虑联合调整信源编码参数，如量化步长和预测模式，以及物理层资源，如传输速率和功率。我们的目标是在考虑可用能量等系统约束的同时提供可接受的服务质量。我们提出了一个通用的框架，它允许一些资源/失真最优的公式来平衡不同应用的需求。

ABSTRACT0311838Pappas, ThrasyvoulosNorthwestern UThere has been much interest in supporting video communication over wireless networks. This isnot a simple task due to the stringent Quality of Service (QoS) required by video applications andthe many impairments of wireless channels. Two important QoS characteristics for video are thedegree of signal distortion and the transmission delay. Wireless channels are lossy, have a timevaryingresponse, and are subject to multi-user interference. Furthermore, since users of a wirelessnetwork are mobile, e.ciently utilizing the available energy is a key consideration.The di.culties inherent in wireless video can be addressed at both the physical layer and thesource coding layer. We jointly consider a combination of these approaches in a cross-layer framework.Speci.cally, we consider jointly adapting source coding parameters, such as the quantizationstep-size and prediction mode, along with physical layer resources, such as the transmission rate andpower. Our goal is to provide acceptable QoS while taking into account system constraints such asthe available energy. We propose a general framework that allows a number of resource/distortionoptimal formulations for balancing the requirements of di.erent applications.