Method and apparatus for channel encoding and decoding in a communication system using a low-density parity check code
A method is provided for channel encoding in a communication system using a Low-Density Parity Check (LDPC) code. The method includes grouping information bits into a plurality of groups, determining an order of the plurality of groups to be shortened, according to a code rate, determining a length of information bits to be obtained by shortening the plurality of groups, shortening the plurality of groups on a group basis in the determined order, based on the determined length of the information bits, and LDPC-encoding shortened information bits.
1. A method for channel encoding in a communication system using low-density parity check (LDPC) codes having different codeword lengths based on a given parity check matrix by performing at least one of shortening or puncturing, the method comprising:
determining a number of bits to be shortened based on a number of input bits;
determining a number of bit groups to be shortened, based on the determined number of bits to be shortened;
shortening one or more bits according to the determined number of bit groups and an order among a plurality of orders according to which the bit groups are shortened;
LDPC-encoding information bits generated from the input bits based on the shortened one or more bits;
puncturing one or more bits in the LDPC-encoded information bits; and
transmitting a signal that is generated from the LDPC-encoded information bits based on the punctured one or more bits,
wherein the plurality of orders are based on puncturing parameters and include a first order and a second order that is different from the first order.
2. The method of claim 1 , wherein if a length of an LDPC codeword is 16200, a length of the information bits is 3240, and the first order is applied, then shortening is performed on 7 th , 6 th , 3 rd , 5 th , 2 nd , 4 th , 1 st , 8 th , and 0 th groups among the bit groups, in order; and
if the length of the LDPC codeword is 16200, the length of the information bits is 3240, and the second order is applied, then shortening is performed on the 7 th , 6 th , 3 rd , 5 th , 2 nd , 4 th , 1 st , 8 th , and 0 th groups among the bit groups, in order.
3. The method of claim 1 , wherein the puncturing parameters include a ratio of a number of the punctured one or more bits to a number of the shortened one or more bits.
4. An apparatus for channel encoding in a communication system using low-density parity check (LDPC) codes having different codeword lengths based on a given parity check matrix by performing at least one of shortening or puncturing, the apparatus comprising:
a shortening pattern applying unit configured to:
determine a number of bits to be shortened, based on a number of input bits,
determine a number of bit groups to be shortened, based on the determined number of bits to be shortened, and
shorten one or more bits according to the determined number of bit groups and an order among a plurality of orders according to which the bit groups are shortened;
an encoder configured to LDPC-encode information bits generated from the input bits based on the shortened one or more bits;
a puncturing pattern applying unit configured to puncture one or more bits in the LDPC-encoded information bits; and
a transmitter configured to transmit a signal that is generated from the LDPC-encoded information bits based on the punctured one or more bits,
wherein the plurality of orders are based on puncturing parameters and include a first order and a second order that is different from the first order.
5. The apparatus of claim 4 , wherein if a length of an LDPC codeword is 16200, a length of the information bits is 3240, and the first order is applied, then shortening is performed on 7 th , 6 th , 3 rd , 5 th , 2 nd , 4 th , 1 st , 8 th , and 0 th groups among the bit groups, in order; and
wherein if the length of the LDPC codeword is 16200, the length of the information bits is 3240, and the second order is applied, then shortening is performed on the 7 th , 6 th , 3 rd , 5 th , 2 nd , 4 th , 1 st , 8 th , and 0 th groups among the bit groups, in order.
6. The apparatus of claim 4 , wherein the puncturing parameters include a ratio of a number of the punctured one or more bits to a number of the shortened one or more bits.
7. A method for channel decoding in a communication system using low-density parity check (LDPC) codes having different codeword lengths based on a given parity check matrix by performing at least one of shortening or puncturing, the method comprising:
receiving, from a transmitter, a signal that is generated from LDPC-encoded information bits, based on punctured one or more bits;
demodulating the signal transmitted from the transmitter;
determining position information of shortened bits related to the signal; and
decoding data based on the determined position information,
wherein determining the position information comprises:
determining a number of the shortened bits,
determining a number of shortened bit groups based on the determined number of the shortened bits, and
acquiring an order of bit groups for shortening bit groups applied to the shortened bit groups among a plurality of orders, and
wherein the plurality of orders are based on puncturing parameters and include a first order and a second order that is different from the first order.
8. The method of claim 7 , wherein if a length of an LDPC codeword is 16200, a length of information bits is 3240, and the first order is applied, then 7 th , 6 th , 3 rd , 5 th , 2 nd , 4 th , 1 st , 8 th , and 0 th groups are determined as shortened, in order; and
wherein if the length of the LDPC codeword is 16200, the length of the information bits is 3240, and the second order is applied, then the 7 th , 6 th , 3 rd , 5 th , 2 nd , 4 th , 1 st , 8 th , and 0 th groups are determined as shortened, in order.
9. The method of claim 7 , wherein the puncturing parameters include a ratio of a number of the punctured one or more bits to a number of the shortened one or more bits.
10. An apparatus for channel decoding in a communication system using low-density parity check (LDPC) codes having different codeword lengths based on a given parity check matrix by performing at least one of shortening or puncturing, the apparatus comprising:
a receiver configured to receive, from a transmitter, a signal that is generated from LDPC-encoded information bits, based on punctured one or more bits;
a demodulator configured to demodulate the signal transmitted from the transmitter;
a shortening pattern determiner configured to determine position information of shortened bits related to the signal; and
a decoder configured to decode data based on the position information,
wherein determining the position information comprises:
determining a number of the shortened bits,
determining a number of shortened bit groups based on the determined number of the shortened bits, and
acquiring an order of bit groups for shortening bit groups applied to the shortened bit groups among a plurality of orders, and
wherein the plurality of orders are based on puncturing parameters and include a first order and a second order that is different from the first order.
11. The apparatus of claim 10 , wherein if a length of an LDPC codeword is 16200, a length of information bits is 3240, and the first order is applied, then 7 th , 6 th , 3 rd , 5 th , 2 nd , 4 th , 1 st , 8 th , and 0 th groups are determined as shortened, in order; and
wherein if the length of the LDPC codeword is 16200, the length of the information bits is 3240, and the second order is applied, then the 7 th , 6 th , 3 rd , 5 th , 2 nd , 4 th , 1 st , 8 th , and 0 th groups are determined as shortened, in order.
12. The apparatus of claim 10 , wherein the puncturing parameters include a ratio of a number of the punctured one or more bits to a number of the shortened one or more bits.