The rate 19/20 trellis code matched to enhanced extended class-4 partial response channel

In this paper, a rate 19/20 trellis code matched to the partial response (PR) channel is presented. Our trellis rode is designed on a multidimensional Euclidean space for which the minimum free Euclidean distance is larger than conventional recording codes. By using this trellis coding, a trellis coded partial response (TCPR) system is defined for the enhanced extended class-4 partial response (E/sup 2/PR4) channel. Further, the decoding method for this TCPR system is based on the syndrome-former trellis decoding. The number of add-compare-selects (ACS's) in our system is fewer than that of conventional Viterbi decoding. The result shows that TCPR system employing this rate 19/20 trellis code with the constraint length 7 for the E/sup 2/PR4 has an excellent performance compared with the conventional 8/9 maximum transition run (MTR) coding system in high-density recording.