Soft-decision Decoding of Reed-solomon Codes Using Pattern Information over Partial Response Channels

Reed-Solomon (RS) codes have been used for a long time in many data storage systems for error correction. Popularity of RS codes is due to their powerful burst error correction capability and well-established decoding algorithm with efficient hardware implementation providing high throughput. Conventional hard-decision decoding algorithms are able to correct up to half the minimum distance. To achieve higher areal density needed these days, enhanced error correction capability is required. Soft information, which is probability information about binary decision, can be used to correct more errors than half the minimum distance. Rapid increase of computing power enables the systems to execute complicated decoding algorithms using soft information. Many soft-decision decoding algorithms for RS codes have been proposed and have been investigated for application to magnetic recording channels. However, even with increased computing power, the complexity of soft-decision decoding algorithms is too high for them to be employed in real applications which require high data rate, small hardware area and low power. Some soft-decision decoding algorithms adopt bit-based decoding schemes using bit reliability. Performance gains in magnetic recording channels provided by