Concatenated Codes and Iterative Decoders for Magnetic Recording Channels

磁记录通道的级联编码和迭代解码器

• 批准号: 9814472
• 负责人: William Ryan
• 金额: $ 20万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9814472&HistoricalAwards=false
• 关键词: Concatenated; Codes; Iterative; Decoders; Magnetic

The integrity of the data stored on magnetic disk and tape drives must be protected from error-inducing noise and distortion using error control codes. The most exciting discovery in quite some time in the area of coding is the so-called turbo code which involves a concatenation (cascading) of two distinct codes in a manner which facilitates iterative ("turbo") decoding. This coding technique has enabled performance near theoretical limits on simple communications channels unlike any code before its discovery. This research investigates the design of turbo codes and related codes for error protection in magnetic recording devices, which may be modeled as a (very difficult) communication channel. The goals in this research involve the design of high performance concatenated codes and their iterative decoders for magnetic recording. Both parallel and serial concatenated codes will be considered. Error control code design for magnetic recording has focused in the past on the design of trellis-oriented codes to maximize the minimum free Euclidean distance between pairs of received sequences. This has been a notoriously difficult problem since, by adding coding and its concomitant overhead, intersymbol interference is increased, hampering the intended benefits of the code. Concatenated codes, on the other hand, are capable of achieving gains not just by increasing overhead (lowering code rate) to increase minimum distance, but via interleaver gain. Early work has shown that unprecendented gains are achievable with concatenated codes and iterative decoding.

必须使用错误控制代码来保护存储在磁盘和磁带驱动器上的数据的完整性，防止错误引起的噪声和失真。编码领域相当长一段时间以来最令人兴奋的发现是所谓的turbo码，它涉及以有利于迭代（“turbo”）解码的方式连接（级联）两个不同的代码。 与发现之前的任何代码不同，这种编码技术在简单通信信道上的性能接近理论极限。 这项研究研究了用于磁记录设备中错误保护的 Turbo 码和相关代码的设计，可以将其建模为（非常困难的）通信通道。 这项研究的目标涉及设计用于磁记录的高性能级联码及其迭代解码器。将考虑并行和串行级联代码。磁记录的差错控制码设计过去集中于网格导向码的设计，以最大化接收序列对之间的最小自由欧几里得距离。这一直是一个众所周知的难题，因为通过增加编码及其伴随的开销，符号间干扰会增加，从而妨碍了代码的预期好处。另一方面，级联码不仅可以通过增加开销（降低码率）来增加最小距离来实现增益，还可以通过交织器增益来实现增益。早期的工作表明，通过级联代码和迭代解码可以实现前所未有的增益。