Wireless Transmission of Low Bit-Rate Video

本研究的目标是为低比特率视频应用开发增强的服务选项，以改善其在基于分组的无线信道上的传输。我们将详细研究编码过程，以便更好地理解服务的底层特征。这项研究将借鉴以往在基于ATM的BISDN网络上的可变比特率视频传输领域的工作所获得的专业知识。目前的工作将集中在H.263标准上，它包含了一个非常复杂的编码过程，包含了几个不同的选项。这些选项对基于分组的无线信道上视频数据传输的影响尚未得到广泛研究。研究计划包括研究不同的编码选项，然后研究分组视频数据传输的网络接入和错误恢复方案。正交频分复用和多载波调制（OFDM和MCM）无线传输方案和天线分集策略的研究对视频应用很有意义，因为它们可以灵活地动态分配信道资源以进行分层视频编码传输。非线性接收器结构和非线性处理图像质量增强，以对抗干扰对视频质量的影响也将进行研究。该研究项目包括在信号处理研究实验室和视频处理和电信实验室建立一个无线试验台。该试验台将用于室内无线视频传输实验。

The goal of this research is the development of enhanced service options for low bit rate video applications to improve their transmission over packet based wireless channels. The encoding process will be studied in detail to better understand the underlying characteristics of the service. This research will draw on expertise gained from previous work in the area of variable bit rate video transmission over ATM based BISDN networks. Current work will focus on the H.263 standard which encompasses a very complex encoding process that incorporates several different options. The impact of these options on the transmission of video data over a packet based wireless channel has not yet been studied extensively. The research plan involves studying the different encoding options and then investigating network access and error recovery schemes for the transmission of packetized video data. The orthogonal frequency division multiplexing and multicarrier modulation (OFDM and MCM) wireless transmission schemes and antenna diversity strategy studied are interesting for video applications because of the flexibility with which channel resources may be dynamically allocated for layered video coding transmission. Nonlinear receiver structures and nonlinear processing for image quality enhancement to combat the effects of interference on video quality will also be studied. The research project includes the set-up of a wireless testbed that will be housed in both the Signal Processing Research Laboratory and the Video Processing and Telecommunications Laboratory. The testbed will be used to conduct experiments on indoor wireless video transmission.