I. Introduction
Improving areal density and throughput in magnetic recording systems [1], [2] motivates the development of multitrack detection in which multiple neighboring tracks are detected jointly [3]–[5]. Existing multitrack detection algorithms, with only two recent exceptions [2] and [3], assume that the tracks being detected are written synchronously [4]–[7]. In practice, however, variations in disk rotational speeds can lead to slightly different bit rates from one track to the next, as illustrated in Fig. 1 for the case of two overlapping readers detecting two neighboring tracks.
An illustration of how neighboring tracks can have different bit rates (the difference is exaggerated for emphasis), with a pair of readers for recovering the bits from both tracks.