CIF: Small: Collaborative Research: New Approaches to the Design of Joint Source-Channel Codes

联合信源信道编码和解码技术正迅速成为复杂度和延迟受限传输系统的重要设计工具，这些传输系统是多媒体革命的基础。在这种情况下，这些技术有可能提供相同的性能，与完全分离的源和信道编码功能的系统相比，具有更小的复杂性或延迟。研究人员通过解决某些类别的最佳变长纠错码及其在网络中的应用，开发了构建联合源信道码的理论见解和实用方法。这些研究所获得的见解促进了新的先进的编码策略，以及指导未来无线和多媒体系统的设计的基本理论。联合信源信道编码的一种方法是考虑前缀条件码，其具有固有的信源压缩特性，并且另外能够检测或校正由通信信道上的噪声引起的错误。因此，这些码通常需要比经典信道码更少量的冗余来实现相同量的差错恢复。然而，目前对这些代码的理解仍然相当有限，这使得研究人员将重点放在了密码学上。调查人员通过在三个相互关联的方向上解决研究问题来解决这些问题。特别是，我们（1）开发新的最小冗余可变长度码与固有的错误恢复性能，并调查有关的问题，他们的设计和压缩性能;（2）研究这一系列的代码的应用，传感器和ad hoc网络，并深入了解他们的影响更高的通信层;（3）研究可逆变长码的构造，包括具有特殊纠错性质的可逆变长码的构造。

Joint source-channel coding and decoding techniques are rapidly emerging as important design tools for the complexity- and latency-constrained transmission systems that underlie the multimedia revolution. In such scenarios these techniques have the potential to offer the same performance with less complexity or delay compared with systems which completely separate the source and channel coding functions. The investigators develop theoretical insights and practical approaches into the construction of joint source-channel codes by addressing certain classes of optimal variable-length error correcting codes and their application to networks. The insights gained by these studies facilitates new advanced coding strategies as well as a fundamental theory that guides the design of future wireless and multimedia systems. One approach to joint source-channel coding is to consider prefix condition codes which have an inherent source compression property and are in addition able to detect or correct errors resulting from noise on the communication channel. Thus, these codes typically require a smaller amount of redundancy than classical channel codes to achieve the same amount of error resilience. However, the current understanding of these codes remains rather limited which has led researchers to focus on heuristics. The investigators address these issues by tackling research problems in three interrelated directions. In particular, we (1) develop new minimum-redundancy variable-length codes with inherent error resilience properties and investigate issues related to their design and compression performance; (2) study the application of this family of codes to sensor and ad hoc networks and gain insight into their repercussions for higher communication layers; (3) investigate the construction of reversible variable-length codes including those with special error-correcting properties.