New Rate 6/9 Run-Length Limited (2,11) Code with Spaced Pits/Lands Constraint for Four-Level Read-Only Optical Disc

摘要

Multi-level run-length limited (ML-RLL) modulation is a novel way to significantly increase the recording density without changing the optical or mechanical units of current optical disc systems. In this paper, a new rate 6/9 RLL (2,11) code with spaced pits/lands (SPL) constraint is designed for four-level read-only digital versatile disc (DVD). The SPL constraint is used to obtain alternate multi-level pits and lands on the disc, and reduce the difficulty of multi-level disc replication. Compared with the former four-level SPL-RLL code with the same code rate, this new code has smaller size of decoding window and smaller parameter k.