Constrained Concatenated Codes for Noisy Channels

本研究的主要目标是为磁性和光学记录设备中遇到的噪声调制信道开发有效的编码。在这些信道中，通常需要将数据映射到具有特殊调制特性的序列；由于大多数设备都有噪声，因此记录的序列也应该具有一定的误差控制能力。编码技术用于将任意数据转换为满足调制和误差控制要求的序列。编码技术是促成当今磁性记录设备惊人容量的关键因素之一。最常用的编码方案是将用于错误控制的外部代码与用于调制的内部代码连接起来。虽然这两个组成代码中的每一个都可能是最优的，但整体连接方案可能不是最优的。现在业界已经认识到，使用这种方法获得的编码增益接近饱和点。本研究的目的是优化整体串联编码方案，而不是优化组件编码。预计这种方法将显著提高总体编码增益。为了完成这一任务，不应该单独设计和实现这两个组成部分的代码。相反，内部代码中的任何错误控制功能都应该由外部代码最佳地利用，以获得更好的性能。该项目的资金将用于支持在数据存储和通信领域有许多应用的研究生，这些应用本质上是跨学科的。在这些应用程序的编码方面需要更多的研究人员。

The primary goal of this research is to develop efficient codes for noisy modulation channels such as those encountered in magnetic and optical recording devices. In these channels, it is often required to map the data to a sequence with special modulation properties; since most devices are noisy, the recorded sequence should have some error control capability as well. Coding techniques are used to transform arbitrary data to sequences that satisfy the modulation and error control requirements. Coding technology is one of the critical factors that has contributed to the astounding capacity of today's magnetic recording devices. The most commonly used coding scheme is based on concatenating an outer code for error control with an inner code for modulation. Although each of the two component codes may be optimal with respect to its function, the overall concatenated scheme may not be optimal. It is recognized now in industry that the coding gain achieved using this approach is close to reaching a saturation point. This research aims at optimizing the overall concatenated coding scheme rather than optimizing the component codes. It is expected that this approach will significantly improve the overall coding gain. To accomplish this task, the two component codes should not be independently designed and implemented. Instead, any error control capability in the inner code should be optimally exploited by the outer code for better performance. Funding for this project will be used to support graduate students in an area with many applications in data storage and communications, which are interdisciplinary in nature. There is a need for more researchers in the coding aspects of these applications.