Bimodulation code for signal waveform modulation multilevel optical disc

摘要

A new method for implementing a multilevel run length limited (ML-RLL) modulation code used in a signal waveform modulation multilevel (SWMM) optical disc, termed bimodulation code (BMC), is proposed. BMC is implemented with two steps: run length modulation and level modulation. A code rate of 5/6 BMC is realised, and the code efficiency reaches 94.47%. The parameter user bits per 400 nm of the presented code is 1.96, which is 30.7% more than that of EFMplus code used in a DVD system.