CIF: Small: Two-Dimensional Channel Modeling, Detection and Coding for Shingled Magnetic Recording

目前的磁记录技术正在迅速接近其每平方英寸1太比特(1TB/in^2)的理论极限，除非开发出能够提供高达10TB/in^2的面密度的新技术，否则硬盘驱动器容量每年增加的速度将迅速减少。目前正在开发几种候选技术，它们将把面密度扩展到4TB/in^2，但只有两种技术可能会一直扩展到10TB/in^2，即位图案化介质上的能量辅助记录和二维磁记录。位图案化介质需要极端的纳米光刻和压印技术，这些技术昂贵得令人望而却步，并且对磁盘表面的平坦化要求非常严格。另一方面，二维磁记录使用传统的磁头和介质，但需要开发适用于磁记录通道的新的二维信号处理和编码技术。该研究计划旨在通过以下方式提供对二维叠瓦式磁记录的深入理解：1)在磁粒级别上开发现实的信道模型；2)开发用于分析此类模型的统计特性的技术；3)开发具有有限的每符号复杂性的二维码间干扰信道检测器；4)开发一种基于循环码的基本代数特性来设计容量逼近码的新颖且变革性的方法；以及5)确定可在实践中实现的最大面记录密度。该研究计划将帮助回答一个基本问题，即是否有可能使用叠片写入达到每个磁粒一个用户位的最终理论极限。该研究计划的更广泛的目标是帮助确定使用叠片写入的面密度高达10TB/in^2的硬盘驱动器的可行性。它的成功完成将使二维磁记录成为下一代磁存储设备的首选技术，并可能塑造这一领域的未来研究。获得如此高的记录密度的意义在于，人们可以在与当前驱动器相同大小的驱动器上存储多达十倍的数据，从而对存储行业产生数十亿美元的经济影响。此外，为检测和编码具有二维符号间干扰的信道而设计的方法在新的二维传输和存储系统变得可用时具有更广泛的应用，例如多口径自由空间光通信系统和全息数据存储系统。

Current magnetic recording technology is fast approaching its theoretical limit of 1 terabit per square inch (1 Tb/in^2), and unless new technology is developed that can deliver areal densities of up to 10Tb/in^2, the annual increases in hard-disk drive capacity will taper rapidly. Several candidate technologies are currently being developed that will extend the areal densities up to 4Tb/in^2, but only two that can possibly extend it all the way to 10Tb/in^2, namely energy assisted recording on bit-patterned media and two-dimensional magnetic recording. Bit-patterned media requires extreme nano-lithography and imprinting techniques, which are prohibitively expensive, and very tight specifications on the planarization of the disk surface. Two-dimensional magnetic recording, on the other hand, uses conventional heads and media, but requires the development of new two-dimensional signal processing and coding techniques suitable for the magnetic recording channel. This research program aims at providing an in-depth understanding of two-dimensional shingled magnetic recording through: 1) development of realistic channel models at the magnetic grain level; 2) development of techniques to analyze the statistical properties of such models; 3) development of two-dimensional intersymbol interference channel detectors with limited per-symbol complexity; 4) development of a novel and transformative approach to the design of capacity-approaching codes based on fundamental algebraic properties of cyclic codes; and 5) determination of the maximum areal recording density that can be achieved in practice. This research program will help answer the fundamental question of whether it is possible to approach the ultimate theoretical limit of one user bit per magnetic grain using shingled writing.The broader goal of this research program is to help determine the feasibility of hard-disk drives with areal densities of up to 10Tb/in^2 using shingled writing. Its successful completion would establish two-dimensional magnetic recording as the technology of choice for the next generation of magnetic storage devices and potentially shape future research in this field. The significance of achieving such a high recording density is that one could store up to ten times as much data on a drive of the same size as current ones, thus fostering a multi-billion dollar economic impact on the storage industry. In addition, the methods devised for detection and coding for channels with two-dimensional intersymbol interference have a wider application to new two-dimensional transmission and storage systems as they become available, for instance multi-aperture free-space optical communication systems and holographic data storage systems.