Inter-track interference free coding and equalization

Abstract

A new coding technique using improved inter-track orthogonal coding (ITOC) was proposed for high track density and/or multi-track recording. The coding has, in principle, the ability to eliminate cross talk from adjacent tracks. The new coding was compared with direct NRZI by a computer simulation. The coding showed superior characteristics to the NRZI in terms of signal-to-noise ratio (S/N) and bit error rate (BER) for additive and jitter noise. These simulation results were confirmed by experiments. Furthermore, to improve the performance of ITOC, PR4 and integral equalization for wave form equalization were also studied. It was shown that the new coding technique has a high ability to establish high track density recording with neither guard bands nor azimuth, and to realize a collective reading system of multi-track channel signals by a single head or simultaneous reading by array heads.