NeTS: Small: QoS Assured Multimedia Communication over Non-stationary Wireless Channels

下一代无线网络的目标是支持诸如语音、数据和多媒体的各种应用。然而，无线信道是不可靠的，并且无线衰落信道的容量是时变的，这可能导致视频/音频质量的严重劣化。因此，它是特别具有挑战性的设计服务质量（QoS）保证机制和多媒体压缩技术的多媒体通信在无线网络。本计画的目的在于发展新的理论与技术，以在非静态无线信道上提供有服务品质保证的多媒体通讯。为了实现这一目标，本文开展了以下研究工作：1）提出一种新的进化谱方法，该方法能够精确地模拟一般非平稳衰落信道的动态特性; 2）提出非平稳衰落信道下多媒体通信的QoS保证的滑模拥塞控制和调度机制;以及3）发展用于信源编码中的因果速率控制的伽马速率理论，以及发展跨层设计以实现多媒体编码和传输的网络友好性和观看者友好性。 本计画所发展的技术将填补非平稳无线信道上多媒体通信服务品质保证的基本认知上的一些重要空白，并为系统设计与算法实作提供理论基础。

The next-generation wireless networks are targeted at supporting various applications such as voice, data, and multimedia. However, wireless channels are unreliable and the capacity of a wireless fading channel is time-varying, which may cause severe degradation to video/audio quality. Therefore, it is particularly challenging to design quality of service (QoS) assurance mechanisms and multimedia compression techniques for multimedia communication over wireless networks. This project aims to develop new theories and techniques for QoS assured multimedia communication over non-stationary wireless channels. To accomplish this goal, the following research tasks are conducted: 1) developing a novel evolutionary spectrum approach, which is able to accurately model the dynamics of general non-stationary fading channels; 2) developing QoS-assured sliding-mode congestion control and scheduling mechanisms for multimedia communication over non-stationary fading channels; and 3) developing gamma rate theory for causal rate control in source coding, and developing cross layer design to achieve both network friendliness and viewer friendliness for multimedia coding and transmission. Techniques developed in this project will fill some important gaps in fundamental understanding of QoS-assured multimedia communication over non-stationary wireless channels, and provide the theoretical underpinning for system design and algorithm implementation.