Kevin D. Fisher

Advanced read channels for magnetic disk drives

Advanced read channels which sample the read signal and process those samples using algorithms borrowed from the communications industry allow us to reach higher storage densities and faster data rates than ever before. In this paper we describe some of the design issues involved in using a PRML (partial-response, maximum-likelihood) channel in a disk drive employing thin-film heads, zoned-recording, and embedded servo sectors. We discuss the effect of high transition densities required for a PRML channel on the design of heads and media. Finally, we survey some additional signal processing methods which might lead to even higher performance in the future. >

Signal processing for 10 GB/in.2 magnetic disk recording and beyond (invited)

After providing an overview of the read channel function in a magnetic disk recording system, we describe a range of possible partial‐response maximum‐likelihood (PRML) detection schemes. Improvements upon the current industry‐standard PRML system can potentially provide substantial increases in areal density, as is shown by means of computer simulation of channel and detector.