Signal processing techniques in magnetic recording

Abstract

Magnetic recording systems for hard disk drives (HDDs) have evolved from longitudinal magnetic recording to perpendicular magnetic recording, and more recently to energy-assisted magnetic recording, to achieve greater capacities and higher areal densities. In this process, signal processing systems have also evolved from amplitude detection with peak detection, partial-response maximum-likelihood (PRML), and iterative decoding, which have contributed to higher densities without compromising the reliability of information while compensating for the characteristics of read/write systems. In this study, the PRML system is explained. In particular, PRML has become the basis for signal processing in magnetic recording and has supported a rapid improvement in the areal density of HDDs along with the adoption of magnetoresistive heads and the iterative decoding system used in current HDDs.