Koichiro Nishimura

High-speed DVD-multi drive system

High speed DVD-RAM and DVD-R recording technologies have been established for the DVD-multi drive system. The developed key components are LSIs, especially a laser diode driver, and an optical pickup.

Architecture of PRML Decoder for BD/HD DVD Compatible System

A partial-response maximum-likelihood (PRML) decode system, which enables to read Blu-ray Disc (BD) and HD DVD, has been developed. This system integrates following two functions; a PRML decoder for BD/HD DVD readout at highspeed, and an improved adaptive equalizer for correcting HD DVDs arbitration.

Adaptive signal processing method using PRML for high density optical disks

Numerous types of DVD recording equipment have emerged on the market, and there is much demand for such optical storage systems with high speed and large capacity for digital high definition broadcasts. However, it becomes difficult to maintain data reliability with increasing recording speed and density, because the signal to noise ratio degrades and recording control of the phase changed mark becomes difficult. To improve the error rate of reproduced data, PRML (partial response maximum likelihood) decoding is expected to be used. We have developed a more advanced method of PRML, where the difference of the reproduced waveform is analyzed and the PRML decoder is compensated. In this paper we report the analysis of the reproduced waveform and the effect of the developed PRML algorithm.