Base station device, terminal device, and communication method

1. A terminal apparatus comprising:

a receiving portion configured to

receive a setting of an initial downlink (DL) bandwidth part (BWP) via a radio resource control (RRC) message, and

receive a downlink control information (DCI) format that schedules a physical downlink shared channel (PDSCH) in an active DL BWP; and

a control portion configured to identify, in a field in the DCI format, a value corresponding to a resource block set to which the PDSCH is allocated and which is indicated by a start resource block and a number of consecutively allocated resource blocks, wherein

the setting of the initial DL BWP comprises setting a first parameter and a second parameter of a control resource set (CORESET) #0,

a value of an identifier of the CORESET #0 is 0,

the first parameter represents a size of the CORESET #0,

the second parameter represents a size of the initial DL BWP,

a serving cell is set with the initial DL BWP and an additional DL BWP,

one of the initial DL BWP and the additional DL BWP is activated as the active DL BWP,

the value identified by the control portion is determined based on a size of a DL BWP, the start resource block, and the number of the consecutively allocated resource blocks,

a size of the DCI format in a common search space (CSS) is determined based on the size of the CORESET #0, and when the field in the DCI format is applied to the active DL BWP, the size of the DL BWP is the size of the CORESET #0, and

a size of the DCI format in a user equipment (UE)-specific search space (USS) is determined based on a size of the active DL BWP, and when the field in the DCI format is applied to the active DL BWP, the size of the DL BWP is the size of the active DL BWP.

2. The terminal apparatus according to claim 1 , wherein

the value identified by the control portion is further determined based on a first value,

when the size of the active DL BWP is greater than the size of the CORESET #0, the first value is determined based on the size of the active DL BWP and the size of the CORESET #0, and

when the size of the active DL BWP is less than the size of the CORESET #0, the first value is 1.

3. The terminal apparatus according to claim 1 , wherein

the initial DL BWP is activated as the active DL BWP, and

the size of the active DL BWP is the size of the initial DL BWP.

4. The terminal apparatus according to claim 1 , wherein

the setting of the first parameter of the CORESET #0 does not comprise a setting of a BWP other than the initial DL BWP,

a field of the first parameter is 4 bits, and

the initial DL BWP comprises the CORESET #0 in a frequency domain.

5. A base station apparatus comprising:

a transmitting portion configured to

transmit a setting of an initial downlink (DL) bandwidth part (BWP) via a radio resource control (RRC) message, and

transmit a downlink control information (DCI) format that schedules a physical downlink shared channel (PDSCH) in an active DL BWP; and

a control portion configured to set, in a field in the DCI format, a value corresponding to a resource block set to which the PDSCH is allocated and which is indicated by a start resource block and a number of consecutively allocated resource blocks, wherein

the setting of the initial DL BWP comprises setting a first parameter and a second parameter of a control resource set (CORESET) #0,

a value of an identifier of the CORESET #0 is 0,

the first parameter represents a size of the CORESET #0,

the second parameter represents a size of the initial DL BWP,

a serving cell is set with the initial DL BWP and an additional DL BWP,

one of the initial DL BWP and the additional DL BWP is activated as the active DL BWP,

the value set by the control portion is determined based on a size of a DL BWP, the start resource block, and the number of the consecutively allocated resource blocks,

a size of the DCI format in a common search space (CSS) is determined based on the size of the CORESET #0, and when the field in the DCI format is applied to the active DL BWP, the size of the DL BWP is the size of the CORESET #0, and

a size of the DCI format in a user equipment (UE)-specific search space (USS) is determined based on a size of the active DL BWP, and when the field in the DCI format is applied to the active DL BWP, the size of the DL BWP is the size of the active DL BWP.

6. The base station apparatus according to claim 5 , wherein

the value set by the control portion is further determined based on a first value,

when the size of the active DL BWP is greater than the size of the CORESET #0, the first value is determined based on the size of the active DL BWP and the size of the CORESET #0, and

when the size of the active DL BWP is less than the size of the CORESET #0, the first value is 1.

7. The base station apparatus according to claim 5 , wherein

the initial DL BWP is activated as the active DL BWP, and

the size of the active DL BWP is the size of the initial DL BWP.

8. The base station apparatus according to claim 5 , wherein

the setting of the first parameter of the CORESET #0 does not comprise a setting of a BWP other than the initial DL BWP,

a field of the first parameter is 4 bits, and

the initial DL BWP comprises the CORESET #0 in a frequency domain.

9. A communication method for a terminal apparatus, the communication method comprising:

receiving a setting of an initial downlink (DL) bandwidth part (BWP) via a radio resource control (RRC) message;

receiving a downlink control information (DCI) format that schedules a physical downlink shared channel (PDSCH) in an active DL BWP; and

identifying, in a field in the DCI format, a value corresponding to a resource block set to which the PDSCH is allocated and which is indicated by a start resource block and a number of consecutively allocated resource blocks, wherein

the setting of the initial DL BWP comprises setting a first parameter and a second parameter of a control resource set (CORESET) #0,

a value of an identifier of the CORESET #0 is 0,

the first parameter represents a size of the CORESET #0,

the second parameter represents a size of the initial DL BWP,

a serving cell is set with the initial DL BWP and an additional DL BWP,

one of the initial DL BWP and the additional DL BWP is activated as the active DL BWP,

the identified value is determined based on a size of a DL BWP, the start resource block, and the number of the consecutively allocated resource blocks,

a size of the DCI format in a common search space (CSS) is determined based on the size of the CORESET #0, and when the field in the DCI format is applied to the active DL BWP, the size of the DL BWP is the size of the CORESET #0, and

a size of the DCI format in a user equipment (UE)-specific search space (USS) is determined based on a size of the active DL BWP, and when the field in the DCI format is applied to the active DL BWP, the size of the DL BWP is the size of the active DL BWP.

10. The communication method according to claim 9 , wherein

the identified value is further determined based on a first value,

when the size of the active DL BWP is greater than the size of the CORESET #0, the first value is determined based on the size of the active DL BWP and the size of the CORESET #0, and

when the size of the active DL BWP is less than the size of the CORESET #0, the first value is 1.

11. The communication method according to claim 9 , wherein

the initial DL BWP is activated as the active DL BWP, and

the size of the active DL BWP is the size of the initial DL BWP.

12. The communication method according to claim 9 , wherein

setting the first parameter of the CORESET #0 does not comprise a setting of a BWP other than the initial DL BWP,

a field of the first parameter is 4 bits, and

the initial DL BWP comprises the CORESET #0 in a frequency domain.