Downlink control information receiving method and user equipment, and downlink control information transmitting method and base station

1. A method performed by a user equipment (UE) in a wireless communication system, the method comprising:

determining a coverage enhancement (CE) mode as one of a plurality of predetermined CE modes comprising a CE mode A and a CE mode B;

receiving downlink control information (DCI) related to scheduling a data channel, wherein a format of the DCI is related to the CE mode; and

communicating the data channel based on the DCI,

wherein determining the CE mode comprises: determining the CE mode based on an index of a physical random access channel (PRACH) resource set comprising a PRACH resource on which a PRACH is transmitted,

wherein the PRACH resource set is related to a CE level for the UE,

wherein the index is determined as one of 0, 1, 2, 3,

wherein based on the index being determined as 0, the CE mode is determined as the CE mode A,

wherein based on the index being determined as 1, the CE mode is determined as the CE mode A,

wherein based on the index being determined as 2, the CE mode is determined as the CE mode B, and

wherein based on the index being determined as 3, the CE mode is determined as the CE mode B.

2. The method of claim 1 , wherein based on the data channel being a physical downlink shared channel (PDSCH) and the CE mode being determined as the CE mode A, the format of the DCI is a first format,

based on the data channel being the PDSCH and the CE mode being determined as the CE mode B, the format of the DCI is a second format, and

wherein the DCI with the first format and the second format of the DCI with the first format are different in: (i) a physical resource block (PRB) assignment field for downlink reception, (ii) a hybrid automatic repeat request (HARQ) process number field, (iii) a transmit power control (TPC) command field for a physical uplink control channel (PUCCH), and (iv) a redundancy version (RV) field.

3. The method of claim 2 , wherein the DCI with the first format comprises (i) the PRB assignment field, (ii) the HARQ process number field, (iii) the TPC command for the PUCCH, and (iv) the RV field, and

wherein each of (i) the PRB assignment field for the downlink reception, (ii) the HARQ process number field, (iii) the TPC command field for the PUCCH, and the (iv) RV field is not included in the second format of the DCI or is smaller than included in the DCI with the first format.

4. The method of claim 1 , wherein based on the data channel being a physical uplink shared channel (PUSCH) and the CE mode being determined as the CE mode A, the format of the DCI is a third format,

based on the data channel being the PUSCH and the CE mode being determined as the CE mode B, the format of the DCI is a fourth format, and

wherein the DCI with the third format and the DCI with the fourth format are different in: (i) a PRB assignment field for uplink transmission, (ii) a TPC command field for the PUSCH, (iii) a channel state information (CSI) request field, and (iv) a sounding reference signal (SRS) request field.

5. The method of claim 4 , wherein the DCI with the third format comprises (i) the PRB assignment field for the uplink transmission, (ii) the TPC command field for the PUSCH, (iii) the CSI request field, and (iv) the SRS field, and

wherein each of (i) the PRB assignment field for the uplink transmission, (ii) the TPC command field for the scheduled PUSCH, (iii) the CSI request field, and (iv) the SRS field is not included in the fourth DCI format or is smaller than included in the DCI with the fourth format.

6. The method of claim 1 , wherein the CE mode is related to a machine type communication (MTC).

7. The method of claim 1 , wherein determining the CE mode further comprises:

determining the CE mode as identical to a CE mode indicated by information indicating the CE mode received through a radio resource control (RRC) signal after an RRC connection setup establishment is completed, and

wherein determining the CE mode based on the PRACH resource set is applied before the RRC connection setup establishment is completed.

8. The method of claim 1 , wherein based on the CE mode being determined as CE mode A, a cross-narrowband scheduling is available for the UE,

wherein based on the CE mode being determined as CE mode B, the cross-narrowband scheduling is not available for the UE, and

wherein the cross-narrowband scheduling denotes a scheduling method related to the DCI received or transmitted in a first narrowband different from a second narrowband in which the DCI is received.

9. A user equipment (UE) configured to operate in a wireless communication system, the UE comprising:

a memory; and

at least one processor coupled with the memory,

wherein the at least one processor is configured to:

determine a coverage enhancement (CE) mode as one of a plurality of predetermined CE modes comprising a CE mode A and a CE mode B;

receive downlink control information (DCI) related to scheduling a data channel, wherein a format of the DCI is related to the CE mode; and

communicate the data channel based on the DCI,

wherein the at least one processor is further configured to:

determine the CE mode based on an index of a physical random access channel (PRACH) resource set comprising a PRACH resource on which a PRACH is transmitted,

wherein the PRACH resource set is related to a CE level for the UE,

wherein the index is determined as one of 0, 1, 2, 3,

wherein based on the index being determined as 0, the CE mode is determined as the CE mode A,

wherein based on the index being determined as 1, the CE mode is determined as the CE mode A,

wherein based on the index being determined as 2, the CE mode is determined as the CE mode B, and

wherein based on the index being determined as 3, the CE mode is determined as the CE mode B.

10. A method performed by a base station (BS) in a wireless communication system, the method comprising:

determining a coverage enhancement (CE) mode for a user equipment (UE), wherein the CE mode is determined as one of a plurality of predetermined CE modes comprising a CE mode A and a CE mode B;

transmitting downlink control information (DCI) related to scheduling a data channel, wherein a format of the DCI is related to the CE mode; and

communicating the data channel related to the DCI,

wherein determining the CE mode comprises:

determining the CE mode based on an index of a physical random access channel (PRACH) resource set comprising a PRACH resource on which a PRACH is received,

wherein the PRACH resource set is related to a CE level for the UE,

wherein the index is determined as one of 0, 1, 2, 3,

wherein based on the index being determined as 0, the CE mode is determined as the CE mode A,

wherein based on the index being determined as 1, the CE mode is determined as the CE mode A,

wherein based on the index being determined as 2, the CE mode is determined as the CE mode B, and

wherein based on the index being determined as 3, the CE mode is determined as the CE mode B.

11. A base station (BS) configured to operate in a wireless communication system, the BS comprising:

a memory; and

at least one processor coupled with the memory,

wherein the at least one processor is configured to:

determine a coverage enhancement (CE) mode for a user equipment (UE), wherein the CE mode is determined as one of a plurality of predetermined CE modes comprising a CE mode A and a CE mode B;

transmit downlink control information (DCI) related to scheduling a data channel, wherein a format of the DCI is related to the CE mode; and

communicate the data channel related to the DCI,

wherein the at least one processor is further configured to:

determine the CE mode based on an index of a physical random access channel (PRACH) resource set comprising a PRACH resource on which a PRACH is received,

wherein the PRACH resource set is related to a CE level for the UE,

wherein the index is determined as one of 0, 1, 2, 3,

wherein based on the index being determined as 0, the CE mode is determined as the CE mode A,

wherein based on the index being determined as 1, the CE mode is determined as the CE mode A,

wherein based on the index being determined as 2, the CE mode is determined as the CE mode B, and

wherein based on the index being determined as 3, the CE mode is determined as the CE mode B.