Joint Source and Channel Coding for Wireless Networks

无线网络的联合源和信道编码

• 批准号: 0635177
• 负责人: Elza Erkip
• 金额: $ 17.66万
• 依托单位: Polytechnic University of New York
• 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: 2007-02-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0635177&HistoricalAwards=false
• 关键词: Joint; Source; Channel; Coding; Wireless

Wireless network design poses several challenges that do not exist in wired networks. The wireless medium suffers from random time variations, the broadcast nature of wireless signals causes interference, the wireless spectrum is limited and mobile terminals have small batteries. These features become especially limiting for applications such as multimedia over wireless and low power sensor networks, where maintaining the end-to-end signal quality given the specific system resources is difficult. This research outlines a cross-layer approach between the application layer and the physical layer to address these problems. The objective is to design joint source and channel coding techniques to minimize the end-to-end source distortion. A general source and channel separation theorem for wireless networks does not exist; optimality of Shannon's separate source and channel code design fails for non-ergodic fading channels or for multiuser communication systems. On the other hand, even when source and channel separation is not optimal, it is desirable to have only a loose coupling between the source and channel coders to simplify the designs. The research addresses joint source and channel coding for the fundamental building blocks of a wireless network, namely single user (point-to-point), multiple access, broadcast and interference channels. The system model is general to encompass different communication scenarios: Correlation among the source signals is allowed, the receivers may have correlated side information, the channel can be time-invariant or fading may be present, links can have multiple degrees of freedom such as multiple antennas or multiple fading blocks. This project investigates the design of optimal joint source and channel coding strategies, and performance improvements when minimal interaction among the source and channel coders is allowed. The goal is to discover scenarios under which separation is optimal, or close to optimal. The information theoretic results will be complemented by analytical and experimental studies for video transmission over wireless channels.

无线网络设计提出了有线网络中不存在的若干挑战。无线介质受到随机时间变化的影响，无线信号的广播性质导致干扰，无线频谱有限，并且移动的终端具有小电池。这些特征对于诸如无线多媒体和低功率传感器网络之类的应用变得特别受限，其中在给定特定系统资源的情况下维持端到端信号质量是困难的。这项研究概述了一个跨层的方法之间的应用层和物理层来解决这些问题。目标是设计联合信源和信道编码技术，以最小化端到端信源失真。无线网络的一般信源和信道分离定理并不存在;香农的分离信源和信道码设计的最优性在非遍历衰落信道或多用户通信系统中失败。另一方面，即使当源和信道分离不是最佳的时，也希望在源和信道编码器之间仅具有松散耦合以简化设计。该研究针对无线网络的基本构建块，即单用户（点对点），多址，广播和干扰信道的联合信源和信道编码。系统模型通常包含不同的通信场景：允许源信号之间的相关性，接收器可以具有相关的边信息，信道可以是时不变的或可能存在衰落，链路可以具有多个自由度，例如多个天线或多个衰落块。本计画探讨最佳联合来源与通道编码策略的设计，以及在允许来源与通道编码器间最小互动时的效能提升。我们的目标是发现分离是最佳或接近最佳的情况。信息理论的结果将补充通过无线信道的视频传输的分析和实验研究。