Patent ID: 7908541

Claim:
A method for transmitting a signal of a signal transmission apparatus in a communication system, the method comprising: generating an interleaved vector by channel-interleaving a Low Density Parity Check (LDPC) codeword according to a channel interleaving rule; and generating a modulation symbol by modulating the interleaved vector according to a modulation scheme; wherein the channel interleaving rule is one of a first channel interleaving rule and a second channel interleaving rule; wherein the first channel interleaving rule is a rule for setting degree distribution for nodes in a factor graph of the LDPC codeword separately for individual levels supported by the modulation scheme, wherein the second channel interleaving rule is a rule for allowing coded bits included in the LDPC codeword to be interleaved according to an unequal error characteristic of the modulation scheme.