Transmitting apparatus and signal processing method thereof
A transmitting apparatus and a receiving apparatus are provided. The transmitting apparatus includes an encoder configured to generate a low density parity check (LDPC) codeword by performing LDPC encoding, an interleaver configured to interleave the LDPC codeword, and a modulator configured to modulate the interleaved LDPC codeword according to a modulation method to generate a modulation symbol. The interleaver performs interleaving by dividing the LDPC codeword into a plurality of groups, rearranging an order of the plurality of groups in group units, and dividing the plurality of rearranged groups based on a modulation order according to the modulation method.
1. A broadcasting signal generation and transmission method comprising:
encoding input bits to generate parity bits using a low density parity check (LDPC) code, wherein the input bits are based on a broadcasting data;
interleaving a codeword comprising the input bits and the parity bits;
mapping bits of the interleaved codeword onto constellation points for 256-quadrature amplitude modulation (QAM);
generating a broadcast signal based on the constellation points using an orthogonal frequency division multiplexing (OFDM) scheme; and
transmitting the broadcast signal,
wherein the interleaving comprises:
splitting the codeword into a plurality of bit groups;
interleaving the plurality of bit groups based on an interleaving order, wherein the interleaving order is obtained based on a code rate of the LDPC code and a length of the codeword; and
interleaving the interleaved plurality of bit groups using a plurality of containers, each of the plurality of containers comprising a first part and a second part, wherein a number of the plurality of containers is equal to a modulation order of the 256-QAM,
wherein a number of bits of each bit group is 360,
wherein if a length of the codeword is 64800 bits, a number of bits to be written in the first part of each of the plurality of containers is 7920, and a number of bits to be written in the second part of each of the plurality of containers is 180, and
wherein if the length of the codeword is 16200 bits, a number of bits to be written in the first part of each of the plurality of containers is 1800 and a number of bits to be written in the second part of each of the plurality of containers is 225.
2. The method as claimed in claim 1 , wherein the interleaving the codeword further comprises:
interleaving the parity bits,
wherein the splitting the codeword into a plurality of bit groups comprises splitting the codeword comprising the input bits and the interleaved parity bits into the plurality of bit groups.