Soft-Decision Decoding of Codes

近年来，人们对高效可靠的数字数据传输和存储系统有了很大的需求。大规模高速数据网络和全球卫星电话的出现加速了这一需求，这些网络和全球卫星电话用于在军事、政府和私人领域交换、处理和存储数字信息。在这些系统的设计中，需要融合电信和计算机技术。设计者主要关心的是传输和存储错误的控制，以便能够获得可靠的数据再现。该研究方案提出了一些实现可靠数据传输和存储的有效手段，其中差错控制编码是实现可靠数据传输的最强有力的技术，已成为几乎所有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用于广泛的数据通信系统中以实现可靠的数据传输。这个项目是为了研究差错控制编码的一个重要方面--码的软判决译码。目的是设计有效的软判决译码算法，以获得最优或次优的误码性能，同时降低译码复杂度和时延。要研究的算法包括：(1)MAP算法；(2)MLD和次优译码算法；(3)基于网格的译码算法；(4)基于二进制分解的里德-所罗门码的Turbo译码。这些译码算法的重要特点是：双向并行处理、代码分解和多级译码。

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.