Soft-Decision Decoding of Codes

近年来，对高效可靠的数字数据传输和存储系统的需求很大。 随着大规模高速数据网络和全球卫星电话的出现，这种需求得到了加速，用于军事、政府和私人领域的数字信息交换、处理和存储。 在设计这些系统时，需要将电信和计算机技术结合起来。 设计者的一个主要关注点是控制传输和存储错误，以便可以获得可靠的数据再现。 本文提出了实现可靠数据传输和存储的有效方法，差错控制编码是实现可靠数据传输的最有力的技术，几乎已成为每一个数据通信系统设计中不可或缺的一部分。 今天，非常复杂的差错控制编码方案被广泛地用于数据通信系统中，以实现可靠的数据传输。 本计画的目的是研究错误控制编码的一个重要方面--码的软判决译码。 我们的目标是设计有效的软判决译码算法的代码，以达到最佳或次优的错误性能，降低解码复杂度和延迟。 要研究的算法包括：（1）MAP算法;（2）MLD和次优解码算法;（3）基于网格的解码算法;以及（4）通过二进制分解的Reed-Solomon码的Turbo解码。 这些译码算法的重要特点是：双向并行处理、码分解和多级译码。

In recent years, there has been a great demand for efficient and reliable digital data transmission and storage systems. This demand has been accelerated by the emergence of large-scale, high-speed data networks and global satellite telephony for exchange, processing, and storage of digital information in military, governmental, and private spheres. A merging of telecommunications and computer technology is required in the design of these systems. A major concern of the designer is the control of transmission and storage errors so that reliable reproduction of data can be obtained. This research proposal addresses some efficient means to achieve reliable data transmission and storage.Error control coding is the most powerful technique for achieving reliable data transmission and has become an integral part in almost every data communication system design. Today very sophistical error control coding schemes are being used in a broad range of data communication systems to achieve reliable data transmission. This project is set up to investigate an important aspect of error control coding, soft-decision decoding of codes. The objective is to devise efficient soft-decision decoding algorithms for codes to attain either optimal or suboptimal error performance with reduced decoding complexity and delay. Algorithms to be investigated include: (1) MAP algorithms; (2) MLD and suboptimum decoding algorithms; (3) trellis-based decoding algorithms; and (4) turbo decoding of Reed-Solomon codes through binary decomposition. Important features in these decoding algorithms are: bi-directional and parallel processing, code decomposition and multistage decoding.