Cyclic two dimensional IT reducing codes

Multitrack recording codes achieve larger storage capacities than separately applied single-track codes. Beside the ordinary intratrack (d) and the global (k) phrase length constraints, a radial (dy) constraint should be introduced. In order to increase immunity to intertrack interference by coding, an additional radial (dy) constraint must be imposed on coded sequences. An ordinary dy-constraint would lead to lower recording densities for the inner than for the outer tracks. A modified, cyclic radial constraint which solves these problems is proposed. Channel capacities and spectra of these codes are also presented.