Effects of limit equalizer in Blu-ray disc format

In 2002, the "limit equalizer" which we developed was utilized in the Blu-ray disc format. The limit equalizer improves signal-to-noise ratio without increasing inter-symbol interference and improves jitter and error rates during operation. The limit equalizer is a nonlinear equalizer and deterioration of individual data patterns had to be verified. We used two methods of computer simulation to study behavior of every data patterns of modulation code. We calculated jitter and error rates on individual data patterns in the case of adding low frequency noise as the degradation factor, and in the case of adding random noise or defocus as the degradation factors. We derived the characteristics of both jitter and error rates on combinations of neighboring run-lengths (preceding and succeeding run-lengths). The results confirmed that both jitter and error rates were improved by the use of a limit equalizer throughout the series of data pattern combinations.