摘要 |
<p>A method and apparatus for coding an information signal are provided. In accordance with one aspect of the invention, the method includes the step of encoding all or a portion of the information signal with a first encoder to generate a first set of redundant bits (preferably r1 bits). The method further includes the step of passing a portion of (and possibly all) the information signal through a structured interleaver to generate an interleaved signal. The method then encodes all or a portion of the interleaved signal with a second encoder to generate a second set of redundant bits (preferably r2 bits). Finally, the method includes the step of concatenating the information signal, the first set of redundant bits, and the second set of redundant bits to form an encoded output signal. A significant aspect of the present invention is the use of a structured interleaver in the encoder. It has been found that the structured interleaver provides a low bit error rate, and a much shorter length (and thus delay) than random interleavers. The foregoing concept apply equally to multi-level coding, wherein a parallel concatenated code defined by a structured interleaver may be utilized as a constituent code in a multi-level encoder.</p> |