Transmitting apparatus and mapping method thereof
A transmitting apparatus is disclosed. The transmitting apparatus includes an encoder to perform channel encoding with respect to bits and generate a codeword, an interleaver to interleave the codeword, and a modulator to map the interleaved codeword onto a non-uniform constellation according to a modulation scheme, and the constellation may include constellation points defined based on various tables according to the modulation scheme.
1. A transmitting apparatus comprising:
an encoder configured to encode input bits to generate parity bits based on a low density parity check (LDPC) code according to 4/15 code rate;
an interleaver configured to interleave a codeword comprising the input bits and the parity bits;
a constellation mapper configured to map bits of the interleaved codeword onto constellation points for 1024-quadrature amplitude modulation (QAM); and
a transmitter configured to transmit a signal based on the constellation points,
wherein each of the constellation points is represented in one of A+Bi, −A+Bi, A−Bi and −A−Bi,
where A is a real component, B is an imaginary component, and each of A and B comprises one of values listed below:
0.1924
0.1940
0.2070
0.2050
0.3056
0.3096
0.2890
0.2854
0.7167
0.7362
0.7500
0.7326
0.9667
0.9665
1.1332
1.4761.