| 摘要 |
<p>Digital data, in the form of blocks delimited by end-of-block words, that is to be coded into variable length codewords, is protected against errors occurring within a block, as well as errors crossing block boundaries, by modulating the respective end-of-block words with a bit or bits of a larger reference pattern which bit or bits have been conditioned to carry information on the content of VLC codewords coding a corresponding (eg. preceding) data block. The 'modulation' may be by means of selecting between different possible end-of-block words dependent upon the value of the conditioned reference pattern bit or bits, or by means of appending the conditioned bit(s) to the end-of-block word. The reference pattern may be a repeated pseudo-random sequence.</p> |
