Performance comparison of (1,7) RLL coded PRML systems and 16/17 (0,6/6) coded PRML systems in perpendicular magnetic recording using double‐layered media

Abstract

SUMMARYThe performance of a partial response maximum likelihood (PRML) system in perpendicular magnetic recording that uses double-layered media perpendicular to the MR head is evaluated. The codes of (1,7) RLL and 16/17 (0,6/6), which are commonly used in modern hard disk equipment, are used as the recording codes. The relationship between the normalized linear density and the desired SNR at the reading point for a bit error rate of 10 4 is determined from a computer simulation, assuming equalization by a transversal filter, and a comparative study is performed. It is shown that a (1,7) RLL coded PRML system has better performance when the recording density is comparatively low. For high recording density, a 16/17 (0,6/6) coded PRML system has shown better performance.