PRML Method on 4/15 Code and 4/11 Code

A 4/15 code and a 4/11 code have been developed for a magnetooptic disk system with a sampling servo mechanism. We propose the application of PR systems instead of differential detection methods. We also adopt Viterbi detection with PR systems as PRML methods. This paper also proposes another signal detection method which makes use of the unique property of the coding rule for the 4/15 code. The bit error rates of our systems were examined by computer simulation and compared with conventional differential detection. The results show that our proposed systems exhibit excellent performance compared with conventional systems.