Joint Source-Channel Coding for Wireless Networks

无线网络的联合源信道编码

• 批准号: 0729210
• 负责人: Krishna Narayanan
• 金额: $ 30万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-10-01 至 2011-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0729210&HistoricalAwards=false
• 关键词: Joint; Source; Channel; Coding; Wireless

0729210 - Joint Source-Channel Coding for Wireless NetworksCurrently, there is a significant demand for reliable, high-quality access to multimedia content over wireless networks. This demand stems from society's growing desire for ubiquitous access to multimedia, whether it be critical medical information (x-rays, real-time patient video), news, or entertainment.Providing such services over wireless networks is challenging because wireless channels are subject to a phenomenon known as fading, due to which the instantaneous link quality from the transmitter to the receiver varies with time, frequency and location. The link quality is often not known at the transmitter, necessitating the use of transmission schemes that are robust tochanges in the link quality. This research involves the design and analysis of efficient encoding schemes for transmission of analog signals such as multimedia signals over fading wireless channels, when the instantaneous link quality is not known at the transmitter. Particular emphasis is placed on techniques which are efficient for broadcasting signals to many users with different link qualities and techniques that allow the reconstruction quality at the receiver to scale gracefully with the link quality.This research focusses on the design and analysis of joint source-channel coding schemes for broadcast channels and non-ergodic wireless channels. Specific problems addressed in the research include - (i) the design of several novel joint source-channel coding schemes based on layered transmission with superposition coding, hybrid digital-analog coding with and without side information and the use of matched tandem-encoding. Such codes are designed for multiple-input multiple-output channels, single-input single-output Gaussian and erasure broadcast channels, and a single-input single-output broadcast channel in the presence of an interference known to the transmitter and unknown to the receiver. (ii) development of tools to understand the potentials and fundamental limits of these schemes, and in the definition of appropriate metrics that are analytically tractable as well as insightful. (iii) construction of practically realizable joint source-channel codes. Particular attention is given to the construction of a single code of moderate length that is simultaneously a good source code and a good channel code when used with practical encoding/decoding algorithms, instead of under hypothetical maximum-likelihood decoding.

当前，存在对通过无线网络对多媒体内容的可靠、高质量访问的显著需求。这种需求源于社会对无处不在的多媒体访问的日益增长的需求，无论是重要的医疗信息（X射线、实时患者视频）、新闻还是娱乐。通过无线网络提供这样的服务是具有挑战性的，因为无线信道受到称为衰落的现象的影响，由于衰落，从发射机到接收机的瞬时链路质量随时间、频率和位置而变化。链路质量在发射机处通常是未知的，这就需要使用对链路质量变化具有鲁棒性的传输方案。本研究涉及的设计和分析的有效编码方案的模拟信号，如多媒体信号在衰落的无线信道传输时，瞬时链路质量是未知的发射机。特别强调的是放置在技术，这是有效的广播信号到许多用户具有不同的链路质量和技术，允许在接收机的重建质量，以规模优雅的链路quality.This研究的重点是联合信源信道编码方案的设计和分析广播信道和非遍历无线信道。在研究中解决的具体问题包括：（i）几个新的联合信源信道编码方案的设计的基础上分层传输叠加编码，混合数字模拟编码和不带边信息和使用匹配的串联编码。这样的码被设计用于多输入多输出信道、单输入单输出高斯和擦除广播信道、以及存在发射机已知而接收机未知的干扰的单输入单输出广播信道。(ii)开发工具，以了解这些计划的潜力和基本限制，并在定义适当的指标，分析易于处理，以及洞察力。(iii)实际上可实现的联合信源信道码的构造。特别注意的是给予建设的一个单一的代码的长度适中，同时是一个很好的源代码和一个很好的信道代码时，使用实际的编码/解码算法，而不是根据假设的最大似然解码。