A simplified noise-predictive partial response maximum likelihood detection using M-algorithm for perpendicular magnetic recording channels

We propose a simplified noise-predictive partial response maximum likelihood (NPML) system in conjunction with M-algorithm for dual-layered perpendicular magnetic recording channels. The complexity, which is increased by the construction of noise prediction filter, can be reduced through the M-algorithm. Despite the complexity of the proposed scheme (M=4) is decreased to 1/4 than one of the full NP(12321)ML system, two systems maintain almost the same bit-error rate and the detection performance of the noise-predictive maximum likelihood is better than that of the conventional PRML.

I. Introduction

Perpendicular magnetic recording (PMR) schemes are a technology for achieving high magnetic recording density beyond the super-paramagnetic limitation. The PMR system with a single-pole-type (SPT) head provides a practical approach for high-density hard disk drives [1]–[3].