Performance comparisons of multi-level codes for high density MO recording

We discuss the performance of the multi-level codes for high density recording on magneto-optical (MO) disks. The performance of multi-level codes is compared with that of run-length limited (RLL) binary codes using the partial response maximum likelihood (PRML) method. The simulations indicate that the multi-level codes have good performance in high density recording and that the PRML method produces little improvement in the performance of multi-level codes compared with those of binary-level codes.