Signal processing methods in telecommunication field applied to optical disc systems

Abstract

The main topic in the telecommunication field is to increase the capacity of information transformation with a limited channel bandwidth. Since the readout and recording bandwidths are also limited in optical disc systems, many technologies in communication systems should be applied to them. In this study, two examples of such technologies, orthogonal frequency division multiplexing (OFDM) and divergence detection methods, were applied to optical disc systems to achieve a higher recording density. I studied optical disc recording and reproduction using the OFDM method, and showed the sample calculation of an approximately 1.5-fold recording density for a BDXL™ system using 5-band multiplexing and 64-quadrature amplitude modulation (64-QAM). Typically, optical disc systems have additional readout channels for objective lens control signals. A dual-phase partial response (PR) signal detection method is demonstrated using an additional signal called tangential push–pull. The calculation result of the method indicates a smaller normalized two-dimensional signal deviation than that of the conventional PR detection method.