Open Access

Graph-Based Channel Detection for Multitrack Recording Channels

EURASIP Journal on Advances in Signal Processing20092008:738281

DOI: 10.1155/2008/738281

Received: 26 March 2008

Accepted: 28 November 2008

Published: 20 January 2009

Abstract

We propose a low complexity detection technique for multihead multitrack recording systems. By exploiting sparseness of two-dimensional partial response (PR) channels, we develop an algorithm which performs belief propagation (BP) over corresponding factor graphs. We consider the BP-based detector not only for partial response channels but also for more practical conventional media and bit-patterned media storage systems, with and without media noise. Compared to the maximum likelihood detector which has a prohibitively high complexity that is exponential with both the number of tracks and the number of intersymbol interference (ISI) taps, the proposed detector has a much lower complexity and a fast parallel structure. For the multitrack recording systems with PR equalization, the price is a small performance penalty (less than one dB if the intertrack interference (ITI) is not too high). Furthermore, since the algorithm is soft-input soft-output in nature, turbo equalization can be employed if there is an outer code. We show that a few turbo equalization iterations can provide significant performance improvement even when the ITI level is high.

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Authors’ Affiliations

(1)
Qualcomm Inc
(2)
Electrical Engineering Department, Ira A. Fulton School of Engineering, Arizona State University
(3)
Seagate Technology

Copyright

© The Author(s). 2008

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.