Coding for two-head recording systems

A reduction in the track width in disc-recording systems results in a desirable increase in areal density, but also in the undesirable appearance of inter-track interference (ITI) and loss of signal-to-noise ratio (SNR). One way the effects of ITI may be alleviated is through the use of multiple-head systems simultaneously writing and reading a number of adjacent tracks. In this paper we investigate the performance of two-track detectors, and design codes that combat two-dimensional interference patterns, ISI in the axial dimension, and ITI in the radial dimension, and recover the loss in SNR due to track-narrowing. Sliding-block decoders and reduced-complexity Viterbi detectors are also designed for these codes, which are seen to more than compensate for the performance loss for a large range of ITI levels