A Theoretical Study on 3-level Recording Code

Abstract

Combined usage of multi-layer media and multi-valued systems is one of the most promising techniques for performing high density magneto-optic recording. This paper reports a theory on channel capacity of conventional ternary recording systems, such as a 3B-2T code or a 4B-3T code, including consideration of a DC-free property. The results of channel capacity under several (d, k, c) constraints are tabulated and compared with those of Jacoby-type ternary recording systems. In addition, a design example of a high efficiency DC-free code, called a 7B-5T code, for practical use is proposed.