A new data modulation method for multi-level optical recording

Previously, we developed a data detection method named DDPR (Data Detection using Pattern Recognition) for multi-level data recording on optical discs [I]. We have added a new data modulation process, LSB (Least Significant Bit) Limited Modulation (LLM), to DDPR in order to reduce data errors. The LLM modulates Il-bit input data into four eight-level data symbols (3 bits x 4 data = 12 bits) using a conversion table that converts three bits in the input data into four bits to be LSBs in the eight-level data. The experimental results showed that coupling LLM with DDPR was effective in reducing data errors.