Coding Technologies for achieving higher capacities and rates in data storage

随着包括音频、视频和数据的数字内容在大小和复杂性上的增加，对具有更快访问时间的更高容量便携式存储设备的需求也在增加。到目前为止，在所有光存储磁盘上使用的经典单轨道技术似乎已经走到了尽头，无论是在容量还是数据速率方面，都是由于物理限制。通过使用二维技术，其中多个轨道存在于宽螺旋内，这取代了以前磁盘的单个轨道，可以将更多信息写入磁盘。通过在二维结构上使用多级编码技术，容量和速率的进一步增加是可能的。为了达到更高的存储容量，这意味着更多的符号间干扰和更高的可能性，通过在制造过程中的存储介质的缺陷的介质噪声，有一个关键的需要，研究实际的，容量接近，错误控制编码（ECC）方案，特别是针对应用程序的数据存储。走向未来的光存储技术的路线已经采取，但没有一个完整的研究的行为，噪声，应用信道编码和容量接近ECC，连同组合的调制，符号检测和编码方案在一个有效的形式，它是不可能的估计现实的程度，任何可能的增益在容量和速率。在开发这些方案之前，必须彻底了解通道及其在读出过程中对光盘上原始数据的限制或影响。最后，一旦开发了所有上述信道建模、检测和ECC方案的软件仿真，就可以实现硬件实现以证明所提出的系统是可行的。

As digital content, including audio, video and data, increases in size and complexity, the demand for higher capacity portable storage devices with faster access times is also increasing. The classical Single Track technology used on all optical storage disks so far seems to have come to an end, both in capacity and data rate due to physical constraints . By using two dimensional techonology where multiple tracks are present within a broad spiral, which replaces the single track of previous disks, more information can be written to disc. Further increase in capacity and rate is possible by using multilevel coding techniques on top on the two dimensional structure. In order to reach higher storage capacities, which imply more intersymbol intereference and higher likelihood of media noise through imperfections of the storage medium during manufacture, there is a crucial need to research practical, capacity approaching, error control coding (ECC) schemes particularly targeted towards applications for data storage. The route towards future optical storage technology has been taken but without a complete study on the behaviour of noise, applying channel coding and capacity approaching ECC, together with the combination of modulation, symbol detection and coding schemes in an effective form, it is impossible to estimate realistically the extent of any possible gain in capacity and rate. Prior to developing these schemes, a thorough understanding of the channel and its limitations or effects on the original data on disc during read-out is essential. Finally, once a software simulation of all the above channel modeling, detection and ECC schemes is developed, a hardware implementation can be realised to prove that the proposed system is feasible.