Modulation and Coding for the Magnetic Recording Channel

现代通信理论在以下方面发挥了重要作用： 提高通信的效率和可靠性 系统. 本研究的目的是实现 存储和检索的效率和可靠性 磁记录系统中的数字数据。 特别是 目的是增加数字数据的封装密度， 也就是说，一个单元中可以存储的数据量 磁介质的面积。 这可以通过 增加线性密度（即， 沿轨道沿着英寸）和/或通过增加 轨道（即，每英寸的磁道数）。 这一切 必须在不牺牲可靠性的情况下完成。 检索数据。 首席研究员将探索两种不同的 用于利用调制和编码来增加 磁记录系统的封装密度。 的 首先是对目前使用的技术的改进， 包括一类称为调制码的代码， 作为错误检测和纠正码。 第二个忽略 本系统和使用的技术已经与 具有类似磁记录特性的通道 渠道 PI将继续搜索调制代码 它具有良好的纠错性能。 特别是， 他将研究具有良好汉明距离的网格码 并满足游程长度约束。 其次，他会试图 为了改进他的信道误差模型， 真实的系统的实际性能。 第三，PI建议 研究，其中包括一个实验计划，他 将对磁盘驱动器和突发性进行测量 在磁记录系统中发生的错误。 这 研究的一部分还包括建立电路， 实现新的信号处理算法， 均衡器以及新的调制和编码系统。 最后 PI建议继续研究新的代码， 确保磁记录数字数据的可靠性 和光学介质。

Modern communications theory has played a major role in increasing the efficiency and reliability of communication systems. The aim of the proposed research is to achieve efficiency and reliability for the storage and retrieval of digital data in magnetic recording systems. Specifically the aim is to increase the packing density of the digital data, that is, the amount of data that can be stored in a unit area of the magnetic media. This can be achieved by increasing the linear density (i.e. the number of bits per inch along a track) and/or by increasing the density of the tracks (i.e., the number of tracks per inch). All of this must be done without sacrificing the reliability of the retrieved data. The principal investigator will explore two distinct techniques for utilizing modulation and coding for increasing the packing density for magnetic recording systems. The first is an improvement of a presently used techniques, including a class of codes called modulation codes, as well as error detection and correction codes. The second ignores the present systems and uses techniques that have worked with channels with characteristics similar to magnetic recording channels. The PI will continue the search for modulation codes that gave good error correction properties. In particular, he will study trellis codes that have good Hamming distance and satisfy run length constraints. Second he will attempt to improve his model for channel errors to better reflect the actual performance of real systems. Third the PI proposes research that includes a experimental program in which he will make measurements on disk drives and of the burstiness of errors that occur in magnetic recording systems. This part of the research also includes building circuitry to implement new signal processing algorithms such as adaptive equalizers, and new modulation and coding systems. Finally the PI proposes to continue research on new codes for insuring the reliability of digital data recorded on magnetic and optical media.