Apparatus and method of transmission using HARQ in communication or broadcasting system
The present disclosure relates to a pre-5 th -Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4 th -Generation (4G) communication system such as Long Term Evolution (LTE). The present disclosure discloses a method for effective retransmission when HARQ is applied to data encoded with a low density parity check (LDCP) code. A data transmission method of the transmitter may include: initially transmitting data encoded with an LDPC code to a receiver; receiving a negative acknowledgement (NACK) from the receiver; determining retransmission related information for data retransmission; and retransmitting, in response to the NACK, LDPC-encoded data based on the retransmission related information.
1. A method performed by a transmitter in a communication system, the method comprising:
identifying input bits to be transmitted;
identifying a code block based on the input bits;
identifying Z, a size of an identity matrix or a cyclically shifted matrix of the identity matrix;
identifying a parity check matrix for a low density parity check (LDPC) encoding based on the Z;
encoding the code block by the LDPC encoding based on the parity-check matrix and the Z;
identifying a redundancy version (RV) index;
generating a bit sequence by a rate matching on the encoded code block based on a bit position;
modulating the bit sequence; and
transmitting the modulated bit sequence,
wherein a part of the code block is not included in the encoded code block, and
the bit position is determined based on the RV index and a multiple of the Z.
2. The method of claim 1 ,
wherein a length of the part of the code block is 2×Z.
3. The method of claim 1 ,
wherein the part of the code block is not transmitted for an initial transmission and any re-transmission.
4. The method of claim 1 ,
wherein the rate matching comprises reordering the encoded code block from the bit position.
5. The method of claim 1 , wherein the encoded code block includes of cyclic redundancy check (CRC) bits.
6. A method performed by a receiver in a communication system, the method comprising:
receiving a signal;
demodulating the received signal to identify a demodulated bit sequence;
identifying Z, a size of an identity matrix or a cyclically shifted matrix of the identity matrix;
identifying a parity check matrix for a low density parity check (LDPC) decoding based on the Z;
identifying a redundancy version (RV) index; and
identifying a code block by the LDPC decoding on the demodulated bit sequence based on the parity check matrix and the Z,
wherein the demodulated bit sequence includes a part of an encoded code block associated with a bit position,
wherein a part of the code block is not included in the demodulated bit sequence, and
wherein the bit position is associated with the RV index and a multiple of the Z.
7. The method of claim 6 ,
wherein a length of the part of the code block is 2×Z.
8. The method of claim 6 ,
wherein the part of the code block is not received for an initial transmission and any re-transmission.
9. The method of claim 6 ,
wherein the demodulated bit sequence includes the part of the encoded code block reordered from the bit position.
10. The method of claim 6 , wherein the demodulated bit sequence includes cyclic redundancy check (CRC) bits.
11. A transmitter in a communication system, the transmitter comprising:
a transceiver; and
a controller coupled with the transceiver and configured to:
identify input bits to be transmitted,
identify a code block based on the input bits,
identify Z, a size of an identity matrix or a cyclically shifted matrix of the identity matrix,
identify a parity check matrix for a low density parity check (LDPC) encoding based on the Z,
encode the code block by the LDPC encoding based on the parity-check matrix and the Z,
identify a redundancy version (RV) index,
generate a bit sequence by a rate matching on the encoded code block based on a bit position,
modulate the bit sequence, and
transmit, via the transceiver, the modulated bit sequence,
wherein a part of the code block is not included in the encoded code block, and
the bit position is determined based on the RV index and a multiple of the Z.
12. The transmitter of claim 11 ,
wherein a length of the part of the code block is 2×Z.
13. The transmitter of claim 11 ,
wherein the part of the code block is not transmitted for an initial transmission and any re-transmission.
14. The transmitter of claim 11 ,
wherein the rate matching comprises reordering the encoded code block from the bit position.
15. The transmitter of claim 11 , wherein the encoded code block includes cyclic redundancy check (CRC) bits.
16. A receiver in a communication system, the receiver comprising:
a transceiver; and
a controller coupled with the transceiver and configured to:
receive, via the transceiver, a signal,
demodulate the received signal to identify a demodulated bit sequence,
identify Z, a size of an identity matrix or a cyclically shifted matrix of the identity matrix,
identify a parity check matrix for a low density parity check (LDPC) decoding based on the Z,
identify a redundancy version (RV) index, and
identify a code block by the LDPC decoding on the demodulated bit sequence based on the parity check matrix and the Z,
wherein the demodulated bit sequence includes a part of an encoded code block associated with a bit position,
wherein a part of the code block is not included in the demodulated bit sequence, and
wherein the bit position is associated with the RV index and a multiple of the Z.
17. The receiver of claim 16 ,
wherein a length of the part of the code block is 2×Z.
18. The receiver of claim 16 ,
wherein the part of the code block is not received for an initial transmission and any re-transmission.
19. The receiver of claim 16 ,
wherein the demodulated bit sequence includes the part of the encoded code block reordered from the bit position.
20. The receiver of claim 16 , wherein the demodulated bit sequence includes cyclic redundancy check (CRC) bits.