I. Introduction
One of the challenges along the path to achieving densities in magnetic recording is the read channel signal processing and coding [1]. While perpendicular recording promises to achieve higher areal densities compared to longitudinal recording, there are a number of problems that need to be solved before its benefits can be fully realized [2]. As far as the read channel is concerned, some of the main challenges will be the processing of transition-noise-dominated signals and the handling of intertrack interference (ITI) and longer erasures. In this paper we investigate the issue of ITI in perpendicular magnetic recording channels (PMRCs). The methods used, however, can be easily applied to off-track interference (OTI) as well.