Designing a new multilevel run-length limited modulation code
Xiangwei Liu, Jing Pei, Longfa Pan, Hailong Liu · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2008
Multilevel modulation coding is the core technology for multilevel optical storage. The technology is employed to increase the capacity of the read-only disc with no change on original recording symbols size. With the combination of multilevel modulation and the run-length limited modulation, short run-length with low levels can form long run-length with high levels while it also suitable for long run-length by short run-lengths. And the DC-suppression can be controlled by the allowance of long run-length without sacrifice effective bits. This double-modulation scheme not only can improve coding efficiency, but also can greatly increase the recording density. In this paper, the theory of multilevel run-length limited modulation coding is discussed. And a high rate of 6/7, five level (1,8) code scheme is proposed. This scheme can increase the recording density compared to that in of DVD. Therefore, it is expected that this proposed scheme could be used for the next high-density multilevel run-length limited modulation optical storage system.