Inter-track interference cancelation in presence of frequency offset for shingled magnetic recording

Abstract

The enormous growth of consumer electronic industry is driving the need for achieving ultra-high areal storage densities. Shingled magnetic recording (SMR) is a promising high density storage technique where shingles are created by overlapping tracks for increasing the track per inch (TPI) and achieving higher areal densities. High TPI values, however, introduce sidetrack interference in the equalized output of the center track sensed through the read head. The problem of removing interference from the center track signal can be formulated as estimating pulse shapes of sidetracks assuming sidetracks are decodable. In this paper, we first propose a solution using the correlation method for estimating the pulse shape and the phase-misalignment. The correlation method fails when there is a frequency offset present from sidetracks. Furthermore, we devise a solution based on the least mean square (LMS) algorithm which can provide time varying estimates of the sidetrack pulse shapes and remove the interference from the center track signal. Experimental and simulation results which corroborate the analysis of the proposed algorithm, demonstrate that the proposed algorithm outperforms other techniques and gives the minimum bit error rate (BER). The complexity of the proposed algorithm is low and it can be easily implemented on the hardware.

Multihead multitrack detection in shingled magnetic recording with ITI estimation

“…Iterative ITI cancellation, which removes ITI from each single-track readback signal before detection. is explored in [3] and [4]. These SHST techniques achieve acceptable performance when ITI is low, but suffer as ITI becomes severe.…”

Multihead Multitrack Detection with ITI Estimation in Next Generation Magnetic Recording System

“…The performance of two single-head/single-track (SHST) detectors are studied in [3]. Iterative ITI cancellation, which removes ITI from each single-track readback signal before detection, is explored in [4] and [5]. These SHST techniques maintain acceptable performance when ITI is low, but suffer as ITI becomes severe.…”

Baseline Wander Cancellation on Trellis for Perpendicular Magnetic Recording

“…The longitudinal magnetic recording can achieve upto 1-30 Gbit/in 2 whereas the perpendicular recording can achieve upto 1 Tbit/in 2 . In future, the demand for several Tbit/in 2 is predicted which can be achieved by novel technologies like TDMR (Two-Dimensional Magnetic Recording) and shingled magnetic recording (SMR) [2], [3], [4], [5], [6], [7]. These technologies achieve densities around 10 Tbit/in.…”