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Research On Key Technologies For Multi-level Optical Disc Using Waveform Modulation

Posted on:2010-02-28Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y TangFull Text:PDF
GTID:1118360308457486Subject:Instrument Science and Technology
Abstract/Summary:PDF Full Text Request
High density and large capacity are the trends of optical storage. Multi-level is a candidate technology to increase storage capacity. A new proposed multi-level method, signal waveform modulation (SWM) multi-level is researched. It is based on conventional DVD production equipment and readout optical pick-up, and it has exclusive physical format. Research on some key technologies on this multi-level method is presented.Storage principle and specific implementation are presented. For SWM multi-level, a sub-pit/sub-land is inserted into the original land/pit in order to change the waveform of readout signal. The waveform is used for level differentiation. Compared to conventional multi-level, which uses signal amplitude for level differentiation, the SWM multi-level has advantages on storage capacity and servo performance. The specific implementation on read-only DVD platform is presented.Due to the insertion of sub-pit/sub-land, the write strategy optimization is different from that of other storage method. A write strategy optimization method based on simulation is proposed. A complete calculation model from mastering to readout signal is established. The optimization target is that the levels are easy to differentiate and the run-length is varied by the sub-pit/sub-land. The write strategy vector for every run-length and every level is achieved by simulation calculatiion. The result is validated on the commercial DVD production line and readout system. The readout waveform agrees with the simulation result. The jitter is below 8% and the error radio of run-length can be kept less than 2×10-4.The SWM employs waveform for the level differentiation, and thus its level detection is difference from other multi-level method. Because the readout signal does not respond to a symbol sequence, the partial response maximum like-hood (PRML) detection cannot be used to the SWM multi-level. A signal detection solution, where level detection is after run-length detection, is proposed. An adaptive level detection method based on minimum Euclid distance is presented. This level detection can overcome the readout signal fluctuation as well as the processing variation of disk production. This detection method is implemented on the hardware platform with FPGA. A level error ratio of less than 2×10-4 is achieved. Constant and stable playback of high definition video is realized.The influence of mastering processing and servo error on the readout signal is analyzed. A parameter, waveform deviation, is defined to evaluation the influence on level detection. By simulation, the readout signals with mastering processing fluctuation and focusing/tracking error are figured out. As well, responding waveform deviations are achieved. The results provide important reference to the control of mastering processing and servo system design.
Keywords/Search Tags:Optical Storage, Waveform Modulation Multi-Level, Write Stratege Opitimization, Level Detection, Mastering Processing
PDF Full Text Request
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