Koubun Sakagami

Data Detection using Pattern Recognition for Multi-level Optical Recording

An optical disc system using multi-level (ML) amplitude-modulation can achieve higher data capacity and transfer rates than previous systems without changing the drive or pick-up head except to add a new chip set to the ML. The ML system can provide a bit error rate (BER) that is fully correctable around the order of 10-5 with sigma to dynamic range (SDR) < 2%. We improved the margin of SDR using a new data detection method that uses pattern recognition and evaluated its performance.

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.