Method and apparatus for determining resource pool

1. A wireless user device comprising:

at least one processor configured to:

determine, for a period having a plurality of consecutive subframes, a first subset of subframes by excluding, from the plurality of consecutive subframes, first subframes comprising:

subframes in which a sidelink synchronization signal (SLSS) resource is configured;

downlink subframes; and

special subframes;

determine, for the period, a second subset of subframes by excluding, from the first subset of subframes, one or more second subframes, wherein a quantity of the second subset of subframes corresponds to an integer multiple of a length of a bitmap for determining a resource pool for a sidelink transmission, and wherein a quantity of the one or more second subframes is determined based on the length of the bitmap; and

determine, from the second subset of subframes and based on a plurality of repetitions of the bitmap, the resource pool for a sidelink transmission; and

a wireless transceiver comprising at least one antenna and configured to:

receive, from a base station, resource pool configuration information indicating the bitmap; and

transmit, from the wireless user device to a second wireless user device, data.

2. The wireless user device of claim 1 , wherein the at least one processor is configured to determine, from among the resource pool and based on downlink control information (DCI) indicating the sidelink transmission, a data transmission subframe for transmitting sidelink data; and

wherein the wireless transceiver is configured to:

receive, from the base station, the DCI; and

transmit, to the second wireless user device and via the determined data transmission subframe, the sidelink data.

3. The wireless user device of claim 2 , wherein the wireless transceiver is configured to receive, from the base station, information of a resource reservation interval; and

wherein the at least one processor is configured to:

determine, based on the determined data transmission subframe and the resource reservation interval, one or more transmission reservation subframes; and

reserve a transmission of the sidelink data in the one or more transmission reservation subframes.

4. The wireless user device of claim 1 , wherein the downlink subframes are Time Division Duplex (TDD) downlink subframes, and wherein the special subframes are TDD special subframes.

5. The wireless user device of claim 1 , wherein the wireless transceiver is configured to receive, from the base station, SLSS configuration information indicating the SLSS resource.

6. The wireless user device of claim 1 , wherein the at least one processor is configured to determine the period based on a system frame number (SFN) reset period or a direct frame number (DFN) reset period.

7. The wireless user device of claim 1 , wherein the wireless user device comprises one or more of: a vehicle-to-everything (V2X) device or a vehicle-to-vehicle (V2V) device, and

wherein the resource pool for a sidelink transmission corresponds to one or more of: a resource pool for a V2X sidelink communication or a resource pool for a V2V sidelink communication.

8. The wireless user device of claim 1 , wherein a quantity of the one or more second subframes is based on a quantity of the first subset of subframes and the integer multiple of the length of the bitmap.

9. The wireless user device of claim 1 , wherein the at least one processor is configured to:

determine, based on the determined resource pool for the sidelink transmission, a first transmission resource for transmitting the data; and

determine, based on the first transmission resource and a resource reservation interval, a second transmission resource.

10. The wireless user device of claim 1 , wherein the wireless transceiver is configured to:

receive, from the base station, information of a resource reservation interval associated with the length of the bitmap.

11. A method comprising:

receiving, by a wireless user device from a base station, resource pool configuration information indicating a bitmap for determining a resource pool for a sidelink transmission;

determining, for a period having a plurality of consecutive subframes, a first subset of subframes by excluding, from the plurality of consecutive subframes, first subframes comprising:

subframes in which a sidelink synchronization signal (SLSS) resource is configured;

downlink subframes; and

special subframes;

determining, for the period, a second subset of subframes by excluding, from the first subset of subframes, one or more second subframes, wherein a quantity of the second subset of subframes corresponds to an integer multiple of a length of the bitmap, and wherein a quantity of the one or more second subframes is determined based on the length of the bitmap; and

determining, from the second subset of subframes and based on a plurality of repetitions of the bitmap, the resource pool for a sidelink transmission; and

transmitting, to a second wireless user device, data.

12. The method of claim 11 , further comprising:

receiving, from the base station, downlink control information (DCI) indicating the sidelink transmission;

determining, from among the resource pool and based on the DCI, a data transmission subframe for transmitting sidelink data; and

transmitting, to the second wireless user device and via the determined data transmission subframe, the sidelink data.

13. The method of claim 12 , further comprising:

receiving, from the base station, information of a resource reservation interval;

determining, based on the determined data transmission subframe and the resource reservation interval, one or more transmission reservation subframes; and

reserving a transmission of the sidelink data in the one or more transmission reservation subframes.

14. The method of claim 11 , wherein the downlink subframes are Time Division Duplex (TDD) downlink subframes, and wherein the special subframes are TDD special subframes.

15. The method of claim 11 , further comprising receiving, from the base station, SLSS configuration information indicating the SLSS resource.

16. The method of claim 11 , further comprising determining the period based on a system frame number (SFN) reset period or a direct frame number (DFN) reset period.

17. The method of claim 11 , wherein the wireless user device comprises one or more of: a vehicle-to-everything (V2X) device or a vehicle-to-vehicle (V2V) device, and

wherein the resource pool for a sidelink transmission corresponds to one or more of: a resource pool for a V2X sidelink communication or a resource pool for a V2V sidelink communication.

18. The method of claim 11 , wherein a quantity of the one or more second subframes is based on a quantity of the first subset of subframes and the integer multiple of the length of the bitmap.

19. The method of claim 11 , further comprising:

determining, based on the determined resource pool for the sidelink transmission, a first transmission resource for transmitting the data; and

determining, based on the first transmission resource and a resource reservation interval, a second transmission resource.

20. The method of claim 11 , further comprising:

receiving, from the base station, information of a resource reservation interval associated with the length of the bitmap.