Xiangwei Liu

New interleaving scheme for error correction code of a multilevel optical storage system

Disc scratches, dusts and noise corruption et al. will cause data sequence errors including random errors and burst errors. With the recording density of multilevel (ML) optical storage system increasing, the same length of scratches on the surface of optical disc will bring more burst errors in ML DVD than conventional optical recording systems, e.g., digital versatile disc (DVD) and compact disc (CD). A new interleaving scheme based on Reed-Solomon code (RS) is proposed to solve this problem. In DVD system, the burden of the Parity of Outer-code (PO) is huge, while the Parity of Innercode (PI) has more correcting ability than needed. The new interleaving algorithm adjusts the structure of data frame and block and improves the interleaving depth of ECC block to reduce the burden of PO. The results of numerical simulations are presented to verify the performance of the new interleaving algorithm compared with RSPC. The new proposed scheme can correct maximum burst error length of the proposed code is 6912 bytes. Burst error correcting capacity of the proposed scheme is improved up to137.4% more than that of the RSPC.

Research on a manufacturing on demand (MOD) system based on DVD download specification

This article introduces DVD Download specification and Manufacturing On Demand (MOD) system firstly. Then it will show a designed MOD system and analyze the function of each part in it. In this system, we need to combine two DVDs files into one disc automatically, so in the last part, the article shows work on this problem and achievement up to now.

Designing a New Multilevel Run-Length Limited Modulation Code

Multilevel modulation coding is the core technology for multilevel optical storage. The technology is employed to increase the capacity of the read-only disc with no change on original recording symbols size. With the combination of multilevel modulation and the run-length limited modulation, short run-length with low levels can form long run-length with high levels while it also suitable for long run-length by short run-lengths. And the DC-suppression can be controlled by the allowance of long run-length without sacrifice effective bits. This double-modulation scheme not only can improve coding efficiency, but also can greatly increase the recording density. In this paper, the theory of multilevel run-length limited modulation coding is discussed. And a high rate of 6/7, five level (1,8) code scheme is proposed. This scheme can increase the recording density compared to that in of DVD. Therefore, it is expected that this proposed scheme could be used for the next high-density multilevel run-length limited modulation optical storage system.