Full Digital Video Read Write Disk Drive Using M-ary Coding

Abstract

We consider the application of real-time storage at full digital video rates. Traditional optical recording systems utilizing binary runlength limited coding, cannot support the coding density required for the data rates and capacities. New optical recording channels [1], have been developed that support non-binary, M-ary (M≥3) coding. In this paper we consider linear optical recording media (such as demonstrated by Optex’s proprietary stimulable phosphor material called Electron Trapping Optical Media, ETOM™) and the system design (see Figure 1) to support the full digital video rate. The system uses a new class of runlength limited M-ary codes, that was constructed using a modified version of the state splitting algorithm due to Adler Coppersmith Hassner[2], These codes increase (by 2-3 times) the data rate and storage density on the disk and improve on the minimum squared Euclidean distance to provide coding gains of up to 1.9 dB above Ungerbock-style trellis codes used for amplitude modulation.