AN ADVANCED SIGNAL-PROCESSING TECHNIQUE DESIGNED FOR MULTILEVEL SIGNAL OPTICAL DISC SYSTEM

We propose a novel signal processing technique by which we can increas e the effective signal to noise ratio of optical discs. This technique is capable of reducing the influence of random noise even when the pl ayback signal contains a distortion. We apply this signal processing t echnique to single carrier independent pit edge recording optical disc system. When a linear recording density of 0.2 mu m/bit and a track p itch of 0.8 mu m for an optical pickup is used in a DVD pickup (lambda =635 nm, NA=0.6), the experimental results show that the system can ob tain tangential and radial skew margins of +/-0.5 degrees and +/-0.75 degrees, respectively. From the experimental results, we estimate that the proposed method is capable of increasing the capacity of DVD by a factor of about 1.2.