Receiver and method for processing a signal thereof
A receiver is provided. The receiver includes: a first decoder configured to decode a superposition-coded signal by using a parity check matrix to generate Low Density Parity Check (LDPC) information word bits and first parity bits corresponding to a first layer signal; an encoder configured to encode the LDPC information word bits and the first parity bits to generate second parity bits, or encode the LDPC information word bits to generate the first parity bits and the second parity bits, by using the parity check matrix; and a second decoder configured to decode a signal which is generated by removing the first layer signal, corresponding to the LDPC information word bits, the first parity bits, and the second parity bits, from the superposition-coded signal, to reconstruct bits transmitted through the second layer signal.
1. A receiver for receiving superposition-coded signal, the receiver comprising:
a first decoder configured to decode the superposition-coded signal to generate information bits corresponding to a first layer signal of the superposition-coded signal based on a parity check matrix of a low density parity check (LDPC) code;
an encoder configured to encode the information bits and first parity bits to generate second parity bits based on the parity check matrix;
an interleaver configured to interleave bits of a codeword comprising the information bits, the first parity bits and the second parity bits;
a mapper configured to map bits of the interleaved codeword to constellation points; and
a second decoder configured to decode a second layer signal of the superposition-coded signal to generate bits corresponding to the second layer signal,
wherein the second layer signal is obtained by removing signal which is based on the constellation points, from the superposition-coded signal.
2. The receiver of claim 1 , wherein the first decoder is configured to decode the superposition-coded signal to generate the information bits and the first parity bits based on the parity check matrix.
3. The receiver of claim 2 , wherein the parity check matrix comprises:
a first parity check matrix comprising a first information sub-matrix and a first parity sub-matrix comprising a dual diagonal matrix; and
a second parity check matrix comprising a second information sub-matrix and a second parity sub-matrix comprising an identity matrix, and
wherein the first parity bits correspond to the first parity sub-matrix, and the second parity bits correspond to the second parity sub-matrix.
4. The receiver of claim 3 , wherein the first decoder is configured to generate the information bits and the first parity bits based on the first parity check matrix or the first parity check matrix and at least a part of the second parity check matrix.
5. The receiver of claim 3 , wherein the first decoder is configured to generate the information bits and the first parity bits based on the parity check matrix or a part of the parity check matrix before a number of iterations exceeds a predetermined number during the decoding, and
generate the information bits and the first parity bits based on the first parity check matrix after the number of iterations exceeds the predetermined number.
6. The receiver of claim 3 , wherein the first decoder is configured to generate the information bits and the first parity bits based on the first parity check matrix and at least one sub-matrix among a plurality of sub-matrixes of the second parity check matrix.
7. The receiver of claim 6 , wherein the plurality of sub-matrixes comprise the second parity sub-matrix and a part of the second information sub-matrix.
8. The receiver of claim 3 , wherein the encoder is configured to encode the information bits and the first parity bits based on the second parity check matrix to generate the second parity bits corresponding to the second parity sub-matrix.
9. The receiver of claim 8 , wherein based on an LDPC syndrome value satisfying a predetermined value according to a syndrome check result with respect to the information bits and the first parity bits based on the first parity check matrix, the encoder is configured to encode the information bits and the first parity bits based on the second parity check matrix to generate the second parity bits corresponding to the second parity sub-matrix.
10. The receiver of claim 1 , wherein the parity check matrix differs from a parity check matrix used by the second decoder to generate the bits corresponding to the second layer signal.
11. A method for receiving a superposition-coded signal, the method comprising:
decoding the superposition-coded signal to generate information bits corresponding to a first layer signal of the superposition-coded signal based on a parity check matrix of a low density parity check (LDPC) code;
encoding the information bits and first parity bits to generate second parity bits based on the parity check matrix;
interleaving bits of a codeword comprising the information bits, the first parity bits and the second parity bits;
mapping bits of the interleaved codeword to constellation points; and
decoding a second layer signal of the superposition-coded signal to generate bits corresponding to the second layer signal,
wherein the second layer signal is obtained by removing a signal which is based on the constellation points, from the superposition-coded signal.
12. The method of claim 11 , wherein the decoding the superposition-coded signal comprises;
decoding the superposition-coded signal to generate the information bits and the first parity bits based on the parity check matrix.
13. The method of claim 12 , wherein the parity check matrix comprises:
a first parity check matrix comprising a first information sub-matrix and a first parity sub-matrix comprising a dual diagonal matrix; and
a second parity check matrix comprising a second information sub-matrix and a second parity sub-matrix comprising an identify matrix, and
wherein the first parity bits correspond to the first parity sub-matrix, and the second parity bits correspond to the second parity sub-matrix.
14. The method of claim 13 , wherein the decoding the superposition-coded signal comprises;
decoding the superposition-coded signal to generate the information bits and the first parity bits based on the first parity check matrix or the first parity check matrix and at least a part of the second parity check matrix.
15. The method of claim 13 , wherein the decoding the superposition-coded signal comprises,
decoding the superposition-coded signal to generate the information bits and the first parity bits based on the parity check matrix or a part of the parity check matrix before a number of iterations exceeds a predetermined number during the decoding, and generate the information bits and the first parity bits based on the first parity check matrix after the number of iterations exceeds the predetermined number.
16. The method of claim 13 , wherein the decoding the superposition-coded signal comprises:
decoding the superposition-coded signal to generate the information bits and the first parity bits based on the first parity check matrix and at least one sub-matrix among a plurality of sub-matrixes of the second parity check matrix.
17. The method of claim 16 , wherein the plurality of sub-matrixes comprise the second parity sub-matrix and a part of the second information sub-matrix.