| 摘要 |
The present invention relates to a coding strategy for joint modulation coding and ECC coding. It relates in particular to the situation where 2D coding is performed along one- dimensionally evolving strips containing a number of bit rows in the radial direction of the strip, which is orthogonal to the former direction. The idea further relates to high-rate modulation coding. According to the invention, a strip is built up by an alternation of two basic sub-units, each with their own modulation code. The first sub-unit comprises a larger number of bit rows, and its (high-rate) modulation code has a high coding efficiency realized through the use of large codewords. The second sub-unit comprises a single or only few bit rows, and its modulation code has a lower efficiency, which makes it much less sensitive to error-propagation: another function of the sub-unit of the second type is to glue sub-units of the first type together while maintaining the 2D constraint also at the boundaries of the subunits of the first type. The first sub-unit relates to most or all of the source data, and is encoded first, prior to ECC coding. The second sub-unit relates to the ECC parities, and possibly the remainder of the source data. Both at the encoder and the decoder, special measures are taken related to the precise order of both modulation code encoders (and decoders), and of the ECC encoder (and decoder).
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