Method for transmitting transport block by using downlink control information in wireless communication system and apparatus therefor

1. A method for transmitting a transport block (TB) in a wireless communication system, the method performed by a user equipment (UE) and comprising:

receiving, from a base station, a first downlink control information (DCI);

selecting a modulation and coding scheme (MCS) table based on the first DCI;

calculating a first transport block size (TBS) based on at least one any one of a format of the first DCI and the selected MCS table; and

transmitting, to the base station, a first TB based on the calculated first TBS,

wherein the first TBS is identical to a second TBS of a second TB transmitted before the first TB is transmitted,

wherein, based on a code rate related to the first TBS, a base graph of a low-density parity-check code (LDPC) related to the first TB is determined as i) a base graph 1, or ii) a base graph 2 different from the base graph 1, and

wherein, (i) based on the first TB being related to a specific logical channel for ultra-reliable and low latency communications (URLLC) and (ii) based on the first TB being related to a retransmission of the second TB, the base graph of the LDPC related to the first TB is determined as the base graph 2 which is same as a base graph of a LDPC related to the second TB, regardless of the code rate related to the first TBS.

2. The method of claim 1 , wherein the first DCI includes a field indicating the MCS table, and wherein the MCS table is selected based on the field.

3. The method of claim 2 , wherein the field indicating the MCS table is joint-coded with a redundancy version (RV).

4. The method of claim 1 , wherein a format of the first DCI is identical to a format of a second DCI transmitted for transmitting the second TB, and wherein the second DCI is transmitted before the first DCI is transmitted.

5. The method of claim 1 , wherein calculating the first TBS includes:

selecting a quantization method based on a predetermined criterion; and

calculating the first TBS using the selected quantization method.

6. The method of claim 5 , wherein the predetermined criterion is set based on an information bit size.

7. The method of claim 6 , wherein the information bit size is larger than 3,824 bits.

8. A user equipment (UE) transmitting a transport block (TB) in a wireless communication system, the UE comprising:

a radio frequency (RF) module including a transceiver for transmitting/receiving a radio signal; and

a processor functionally connected with the RF module, wherein the processor is configured to:

receive, from a base station, a first downlink control information (DCI) from a base station;

select a modulation and coding scheme (MCS) table based on the first DCI;

calculate a first transport block size (TBS) based on at least one any one of a format of the first DCI and the selected MCS table; and

transmit, to the base station, a first TB based on the calculated first TBS, and

wherein the first TBS is identical to a second TBS of a second TB transmitted before the first TB is transmitted,

wherein, based on a code rate related to the first TBS, a base graph of a low-density parity-check code (LDPC) related to the first TB is determined as i) a base graph 1, or ii) a base graph 2 different from the base graph 1, and

wherein, (i) based on the first TB being related to a specific logical channel for ultra-reliable and low latency communications (URLLC) and (ii) based on the first TB being related to a retransmission of the second TB, the base graph of the LDPC related to the first TB is determined as the base graph 2 which is same as a base graph of a LDPC related to the second TB, regardless of the code rate related to the first TBS.

9. The UE of claim 8 , wherein the first DCI includes a field indicating the MCS table, and wherein the MCS table is determined based on the field.

10. The UE of claim 9 , wherein the field indicating the MCS table is joint-coded with a redundancy version (RV).

11. The UE of claim 8 , wherein a format of the first DCI is identical to a format of a second DCI transmitted for transmitting the second TB, and wherein the second DCI is transmitted before the first DCI is transmitted.

12. The UE of claim 8 , wherein the processor:

selects a quantization method based on a predetermined criterion; and

calculates the first TBS using the selected quantization method.

13. The UE of claim 12 , wherein the predetermined criterion is set based on an information bit size.

14. The UE of claim 13 , wherein the information bit size is larger than 3,824 bits.

15. A method for receiving a transport block (TB) in a wireless communication system, the method performed by a base station and comprising:

transmitting, to a user equipment (UE), a first downlink control information (DCI); and

receiving, from the UE, a first TB based on a first transport block size (TBS), wherein the first TBS is calculated based on at least any one of a format of the first DCI and a modulation and coding scheme (MCS) table selected based on the first DCI,

wherein the first TBS is identical to a second TBS of a second TB received from the UE before the first TB is received,

wherein, based on a code rate related to the first TBS, a base graph of a low-density parity-check code (LDPC) related to the first TB is determined as i) a base graph 1, or ii) a base graph 2 different from the base graph 1, and

wherein, (i) based on the first TB being related to a specific logical channel for ultra-reliable and low latency communications (URLLC) and (ii) based on the first TB being related to a retransmission of the second TB, the base graph of the LDPC related to the first TB is determined as the base graph 2 which is same as a base graph of a LDPC related to the second TB, regardless of the code rate related to the first TBS.