A reliable signal detection method for the combination of PRML method and ternary recording code

We focus our attention on a method for finding the merging state after the ACS (add compare select) operation in a Viterbi algorithm combined with the PR method and the ternary recording system. Firstly, the path shape matrix method is introduced with algebraic lucidity. Secondly, we propose a "rosary" style method that is far much simpler than the path shape matrix method.<<ETX>>