초록 ▼

Apparatus for decoding digital signals, such as digital television signals, which have been transmitted by concatenated coded modulation using partitioning levels of a constellation of points representing different code values. The apparatus includes successive decoding stages which respectively ope

Apparatus for decoding digital signals, such as digital television signals, which have been transmitted by concatenated coded modulation using partitioning levels of a constellation of points representing different code values. The apparatus includes successive decoding stages which respectively operate on the successive partitioning levels of the constellation. Each decoding stage includes a detector for detecting received points in the relevant partitioning level. At least one stage includes an internal decoder for generating estimated bit sequences in accordance with an inner code and erasures of bit sequences for which the estimation is found to be ambiguous, an external decoder decoding in accordance with an outer code and correcting bit sequence erasures, and an encoder for encoding the output of the external decoder and supplying the resulting re-encoded bit sequences to the succeeding stages of the decoding apparatus to validate detection thereby of points in their partitioning levels. The apparatus may be arranged to produce only a predetermined maximum number of erased bit sequences.

대표청구항 ▼

Apparatus for decoding a received digital signal representing a series of modulated code words each of which has been formed by concatenated encoding of one or more of the symbols in a corresponding information word in accordance with an inner code and an outer code and modulation of the resulting e

Apparatus for decoding a received digital signal representing a series of modulated code words each of which has been formed by concatenated encoding of one or more of the symbols in a corresponding information word in accordance with an inner code and an outer code and modulation of the resulting encoded information word in accordance with modulation values corresponding to points in successive partitioning levels of a constellation of modulation values; said decoding apparatus comprising successive decoding stages for the successive partitioning levels of said constellation, each decoding stage including detection means for receiving the digital signal and deriving therefrom bit sequences corresponding to points in the relevant partitioning level of said constellation, at least one of said decoding stages further comprising: internal decoding means for decoding the bit sequences derived by said detection means by estimating in accordance with said inner code, so as to derive estimated inner decoded bit sequences, said decoding including erasure of inner decoded bit sequences for which the estimation decision is ambiguous; external decoding means for receiving the inner decoded bit sequences and erasures from the internal decoding means and decoding in accordance with said outer code so as to derive outer decoded bit sequences, the outer decoded bit sequences including correction of said erasures; encoding means coupled to said external decoding means for re-encoding the outer decoded bit sequences and supplying the re-encoded bit sequences to the detection means of all decoding stages succeeding said one decoding stage, the re-encoded bit sequences enabling the detection means in said succeeding decoding stages to validate that the bit sequences derived thereby correspond to points in the relevant partitioning levels of said constellation; and storage means coupled to all of said decoding stages for combining the outer decoded bit sequences derived by said at least one decoding stage with bit sequences derived by the remaining decoding stages, the combined bit sequences constituting successive decoded information words corresponding to successive modulated code words of the received digital signal.