Research on Development of Ultrahigh-Density Storage System Using Perpendicular Magnetic Recording

1. 垂直磁记录用PRML系统的研制研究了双层介质垂直磁记录用PRML系统。开发了几个以多项式为唯一正系数的高阶PRML系统，例如pr (1,2,3,2,1) ML系统，该系统适用于使用RLL码（如16/17（0,6/6）码）进行高密度记录。在此基础上，提出了适用于具有抖动介质噪声的垂直磁记录通道的直流非平衡PRML系统，如E^2PR3ML和E^3PR3ML系统。开发了E^2PR2ML、ME^2PR2ML和ME^3PR2ML等高阶正系数的3/4MTR编码PRML系统，在高记录密度下表现出优异的性能。垂直磁记录高密度读写仿真系统的研制研制了一种垂直磁记录高密度读写仿真系统，该系统由转盘、个人计算机、任意波形发生器和数字存储示波器组成。这些设备通过GPIB接口相互连接，能够根据来自个人计算机的控制信号交换数据。该系统可以对磁头和介质的几种特性进行评估，并对信号处理方法的性能进行评估。利用高密度的垂直磁记录读写仿真系统，对采用不同RLL码的串行串联turbo编码系统的性能进行了评价。结果表明，采用64/65（0,8）码和PR2编码的系统在RLL编码、串行集中turbo编码系统中性能最好，可以实现57.3Gbit/inch^2的高面密度。

1. Development of PRML Systems for Perpendicular Magnetic RecordingPRML systems for perpendicular magnetic recording using a double layered medium are studied. Several higher order PRML systems characterized by the polynomials with the only positive coefficients, e.g.PR (1,2,3,2,1) ML system, which are suited for high density recording usig RLL codes such as 16/17 (0,6/6) code are developed. Then, DC-unbalanced PRML systems such as E^2PR3ML and E^3PR3ML systems which are effective for a perpendicular magnetic recording channel with jitter-like medium noise are developed. The 3/4MTR coded higher order PRML systems with positive coefficients such as E^2PR2ML, ME^2PR2ML and ME^3PR2ML which show the excellent performance at high recording densities are also developed.2. Development of High-Density R/W Simulation System for Perpendicular Magnetic RecordingA high-density read/write simulation system for perpendicular magnetic recording which consists of a spinstand, a personal computer, an arbitrary waveform gengerator and a digital storage oscilloscope is developed. These devices are conected each other through GPIB interfaces and are able to exchange data according to controll signals from a personal computer. The system can evaluate the several characteristics of heads and media, and evaluate the performance of signal processing methods.3. Performance Evaluation Using Simulation SystemUsing a high-density read/write simulation system for perpendicular magnetic recording, the performance of serially concatenated turbo coding systems using various RLL codes is evaluated. The results show that the system using a 64/65 (0,8) code and PR2 provides the best performance among RLL coded, serially conctenated turbo coding systems, which can achieve an high areal density of 57.3Gbit/inch^2.