Methods and apparatuses for uplink channel sounding between BWPs

1. A method comprising:

receiving first information for a set of uplink (UL) bandwidth parts (BWPs) of a serving cell, wherein the set of UL BWPs includes more than one UL BWP;

receiving second information, for each UL BWP from the set of UL BWPs, for sounding reference signal (SRS) resource sets;

receiving third information that provides:

a first periodicity for SRS transmissions only in an active UL BWP, and

a second periodicity for SRS transmissions in each UL BWP from the set of UL BWPs;

determining, for each UL BWP from the set of UL BWPs, corresponding first SRS resources from the SRS resource sets;

transmitting a first SRS in the active UL BWP according to the first periodicity; and

transmitting a second SRS, in each UL BWP from the set of UL BWPs, according to the second periodicity and using the corresponding first SRS resources.

2. The method of claim 1 , further comprising:

receiving fourth information providing a mapping among SRS resources for each UL BWP from the set of UL BWPs and values of a SRS request field;

receiving a physical downlink control channel (PDCCH) that provides a downlink control information (DCI) format, wherein the DCI format includes the SRS request field; and

determining, for each UL BWP from the set of UL BWPs, the corresponding first SRS resources based on the value of the SRS request field in the DCI format.

3. The method of claim 1 , further comprising:

receiving fourth information for a second set of UL BWPs, wherein the set of UL BWPs is a subset of the second set of UL BWPs;

receiving fifth information providing a mapping among subsets of the second set of UL BWPs and values of a SRS request field; and

receiving a physical downlink control channel (PDCCH) that provides a downlink control information (DCI) format, wherein the DCI format includes a SRS request field with a value that indicates the set of UL BWPs.

4. The method of claim 1 , further comprising:

receiving fourth information providing a mapping among SRS resources, for each UL BWP from the set of UL BWPs, and values of a SRS request field;

receiving a physical downlink control channel (PDCCH) that provides a downlink control information (DCI) format, wherein:

the DCI format includes a number of SRS request fields equal to a number of UL BWPs in the set of UL BWPs, and

the SRS request fields have a one-to-one mapping with the UL BWPs; and

determining, for each UL BWP from the set of UL BWPs, the corresponding first SRS resources based on a value of a corresponding SRS request field in the DCI format.

5. The method of claim 1 , further comprising:

receiving a physical downlink control channel (PDCCH) that provides a downlink control information (DCI) format that includes a transmission power control (TPC) command field;

determining a power based on the TPC command field; and

transmitting the second SRS in each UL BWP from the set of UL BWPs using the power.

6. The method of claim 1 , wherein an active UL BWP is not included in the set of UL BWPs.

7. A user equipment (UE) comprising:

a transceiver configured to receive:

first information for a set of uplink (UL) bandwidth parts (BWPs) of a serving cell, wherein the set of UL BWPs includes more than one UL BWP,

second information, for each UL BWP from the set of UL BWPs, for sounding reference signal (SRS) resource sets,

third information that provides:

a first periodicity for SRS transmissions only in an active UL BWP, and

a second periodicity for SRS transmissions in each UL BWP from the set of UL BWPs; and

a processor operably connected to the transceiver, the processor configured to determine, for each UL BWP from the set of UL BWPs, corresponding first SRS resources from the SRS resource sets,

wherein the transceiver is further configured to transmit:

a first SRS in the active UL BWP according to the first periodicity, and

a second SRS, in each UL BWP from the set of UL BWPs, according to the second periodicity and using the corresponding first SRS resources.

8. The UE of claim 7 , wherein:

the transceiver is further configured to receive:

fourth information providing a mapping among SRS resources for each UL BWP from the set of UL BWPs and values of a SRS request field, and

a physical downlink control channel (PDCCH) that provides a downlink control information (DCI) format, wherein the DCI format includes the SRS request field; and

the processor is further configured to determine, for each UL BWP from the set of UL BWPs, the corresponding first SRS resources based on the value of the SRS request field in the DCI format.

9. The UE of claim 7 , wherein the transceiver is further configured to receive:

fourth information for a second set of UL BWPs, wherein the set of UL BWPs is a subset of the second set of UL BWPs,

fifth information providing a mapping among subsets of the second set of UL BWPs and values of a SRS request field, and

a physical downlink control channel (PDCCH) that provides a downlink control information (DCI) format, wherein the DCI format includes a SRS request field with a value that indicates the set of UL BWPs.

10. The UE of claim 7 , wherein:

the transceiver is further configured to receive:

fourth information providing a mapping among SRS resources, for each UL BWP from the set of UL BWPs, and values of a SRS request field, and

a physical downlink control channel (PDCCH) that provides a downlink control information (DCI) format;

the DCI format includes a number of SRS request fields equal to a number of UL BWPs in the set of UL BWPs;

the SRS request fields have a one-to-one mapping with the UL BWPs; and

the processor is further configured to determine, for each UL BWP from the set of UL BWPs, the corresponding first SRS resources based on a value of a corresponding SRS request field in the DCI format.

11. The UE of claim 7 , wherein:

the transceiver is further configured to receive a physical downlink control channel (PDCCH) that provides a downlink control information (DCI) format that includes a transmission power control (TPC) command field;

the processor is further configured to determine a power based on the TPC command field; and

the transceiver is further configured to transmit the second SRS in each UL BWP from the set of UL BWPs using the power.

12. The UE of claim 7 , wherein an active UL BWP is not included in the set of UL BWPs.

13. A base station (BS) comprising:

a transceiver configured to transmit:

first information for a set of uplink (UL) bandwidth parts (BWPs) of a serving cell, wherein the set of UL BWPs includes more than one UL BWP, and

second information, for each UL BWP from the set of UL BWPs, for sounding reference signal (SRS) resource sets,

third information that provides:

a first periodicity for SRS transmissions only in an active UL BWP, and

a second periodicity for SRS transmissions in each UL BWP from the set of UL BWPs; and

a processor operably connected to the transceiver, the processor configured to determine, for each UL BWP from the set of UL BWPs, corresponding first SRS resources from the SRS resource sets,

wherein the transceiver is further configured to receive;

a first SRS in the active UL BWP according to the first periodicity, and

a second SRS, in each UL BWP from the set of UL BWPs, according to the second periodicity and using the corresponding first SRS resources.

14. The BS of claim 13 , wherein:

the transceiver is further configured to transmit:

fourth information providing a mapping among SRS resources for each UL BWP from the set of UL BWPs and values of a SRS request field, and

a physical downlink control channel (PDCCH) that provides a downlink control information (DCI) format, wherein the DCI format includes the SRS request field; and

the processor is further configured to determine, for each UL BWP from the set of UL BWPs, the corresponding first SRS resources based on the value of the SRS request field in the DCI format.

15. The BS of claim 13 , wherein the transceiver is further configured to transmit:

fourth information for a second set of UL BWPs, wherein the set of UL BWPs is a subset of the second set of UL BWPs,

fifth information providing a mapping among subsets of the second set of UL BWPs and values of a SRS request field, and

a physical downlink control channel (PDCCH) that provides a downlink control information (DCI) format, wherein the DCI format includes a SRS request field with a value that indicates the set of UL BWPs.

16. The BS of claim 13 , wherein:

the transceiver is further configured to transmit:

fourth information providing a mapping among SRS resources, for each UL BWP from the set of UL BWPs, and values of a SRS request field, and

a physical downlink control channel (PDCCH) that provides a downlink control information (DCI) format;

the DCI format includes a number of SRS request fields equal to a number of UL BWPs in the set of UL BWPs;

the SRS request fields have a one-to-one mapping with the UL BWPs; and

the processor is further configured to determine, for each UL BWP from the set of UL BWPs, the corresponding first SRS resources based on a value of a corresponding SRS request field in the DCI format.

17. The BS of claim 13 , wherein an active UL BWP is not included in the set of UL BWPs.