Method and apparatus for determining HARQ timing in wireless communications
Sidelink downlink control information may include a first indicator field that indicates a sidelink hybrid automatic repeat request (HARQ) feedback timing. A bitwidth of the first indicator field may be based on at least one of one or more parameters from the base station. The first wireless user device may transmit, based on the SL DCI and to a second wireless user device, a first sidelink signal. The first wireless user device may receive, during a first time interval and from the second wireless user device, first sidelink HARQ feedback information responsive to the first sidelink signal. The first wireless user device may determine, based on the sidelink HARQ feedback timing and based on the first time interval, a second time interval. The first wireless user device may transmit, during the second time interval and to the base station, the first sidelink HARQ feedback information.
1. A wireless user device comprising:
an antenna;
at least one processor; and
a memory storing instructions that, when executed by the at least one processor, cause the wireless user device to:
receive, from a base station, one or more radio resource control (RRC) signals indicating one or more parameters associated with sidelink communication between wireless user devices;
receive, from the base station, sidelink downlink control information (SL DCI) comprising a first indicator field that indicates a sidelink hybrid automatic repeat request (HARQ) feedback timing, wherein a bitwidth of the first indicator field is based on at least one of the one or more parameters;
based on the SL DCI, transmit, to a second wireless user device, a first sidelink signal;
during a first time interval, receive, from the second wireless user device, first sidelink HARQ feedback information responsive to the first sidelink signal;
determine, based on the sidelink HARQ feedback timing and based on the first time interval, a second time interval, wherein the one or more parameters indicate information of a time window that comprises the second time interval, wherein the time window comprises a plurality of discontinuous time intervals, and wherein each of the plurality of discontinuous time intervals corresponds to one or more uplink slots; and
during the second time interval, transmit, to the base station, the first sidelink HARQ feedback information.
2. The wireless user device of claim 1 , wherein a value of the first indicator field indicates a timing offset between the first time interval and the second time interval.
3. The wireless user device of claim 1 , wherein the time window is configured for the wireless user device to transmit sidelink HARQ feedback information to the base station.
4. The wireless user device of claim 1 , wherein the instructions, when executed by the at least one processor, cause the wireless user device to:
determine, based on the bitwidth and based on the SL DCI, a value of the first indicator field, and
determine the sidelink HARQ feedback timing by determining, based on the value of the first indicator field, the sidelink HARQ feedback timing.
5. The wireless user device of claim 1 , wherein the bitwidth corresponds to 1, 2, or 3.
6. The wireless user device of claim 1 , wherein the one or more parameters indicate one or more timing offset values associated with available timing offsets between the first time interval and the second time interval, and
wherein the bitwidth is determined based on a quantity of the one or more timing offset values.
7. The wireless user device of claim 1 , wherein the instructions, when executed by the at least one processor, cause the wireless user device to:
transmit the first sidelink signal by transmitting the first sidelink signal via a physical sidelink shared channel (PSSCH);
wherein the first time interval corresponds to a physical sidelink feedback channel (PSFCH) reception slot; and
wherein the second time interval corresponds to an uplink slot or a slot comprising one or more uplink symbols.
8. The wireless user device of claim 1 , wherein the instructions, when executed by the at least one processor, cause the wireless user device to:
receive, from the base station, second SL DCI comprising a second indicator field that indicates a second sidelink HARQ feedback timing;
based on the second SL DCI, transmit, to the second wireless user device or a third wireless user device, a second sidelink signal;
during a third time interval, receive second sidelink HARQ feedback information responsive to the second sidelink signal;
determine, based on the second sidelink HARQ feedback timing and based on the third time interval, the second time interval to transmit the second sidelink HARQ feedback information; and
during the second time interval, transmit, to the base station, the second sidelink HARQ feedback information.
9. The wireless user device of claim 8 , wherein the first sidelink HARQ feedback information and the second sidelink HARQ feedback information are multiplexed.
10. The wireless user device of claim 1 , wherein the first indicator field indicates a physical sidelink feedback channel (PSFCH) to physical HARQ timing.
11. The wireless user device of claim 1 , wherein the one or more parameters indicate a size of a time window for transmitting sidelink HARQ feedback information to the base station, and
wherein the SL DCI indicates a slot, in the time window, for transmitting the first sidelink HARQ feedback information to the base station.
12. The wireless user device of claim 1 , wherein the instructions, when executed by the at least one processor, cause the wireless user device to:
determine, based on the first indicator field indicating a first value, that the first time interval and the second time interval are in a same slot.
13. A wireless user device comprising:
a transceiver;
at least one processor; and
a memory storing instructions that, when executed by the at least one processor, cause the wireless user device to:
receive, from a base station, one or more parameters associated with sidelink communication between wireless user devices;
receive, from the base station, sidelink downlink control information (SL DCI) comprising a first indicator field that indicates a sidelink hybrid automatic repeat request (HARQ) feedback timing;
after receiving the SL DCI, transmit, to a second wireless user device, a first sidelink signal via a physical sidelink shared channel (PSSCH);
during a first time interval, receive, from the second wireless user device, first sidelink HARQ feedback information responsive to the first sidelink signal;
determine, based on the sidelink HARQ feedback timing and based on reception of the first sidelink HARQ feedback information, a second time interval, wherein the one or more parameters indicate information of a time window that comprises the second time interval, wherein the time window comprises a plurality of discontinuous time intervals, and wherein each of the plurality of discontinuous time intervals corresponds to one or more uplink slots; and
during the second time interval, transmit, to the base station, the first sidelink HARQ feedback information.
14. The wireless user device of claim 13 , wherein the instructions, when executed by the at least one processor, cause the wireless user device to:
receive one or more radio resource control (RRC) signals indicating the one or more parameters;
wherein a bitwidth of the first indicator field is based on at least one of the one or more parameters; and
wherein the instructions, when executed by the at least one processor, cause the wireless user device to determine the second time interval based on the first time interval.
15. The wireless user device of claim 13 , wherein the instructions, when executed by the at least one processor, cause the wireless user device to:
determine, based on at least one of the one or more parameters, a bitwidth of the first indicator field; and
determine, based on the SL DCI and the determined bitwidth of the first indicator field, a value of the first indicator field.
16. The wireless user device of claim 15 , wherein the value of the first indicator field is associated with a quantity of slots between a first slot comprising the first time interval and a second slot comprising the second time interval.
17. The wireless user device of claim 13 , wherein the instructions, when executed by the at least one processor, cause the wireless user device to:
receive, from the base station, one or more radio resource control (RRC) signals indicating at least one of:
one or more semi-static sidelink transmission resources; or
a slot of a time window for transmitting sidelink HARQ feedback information to the base station.
18. The wireless user device of claim 13 , wherein the SL DCI further comprise a physical uplink control channel (PUCCH) resource indicator field indicating one or more uplink resources for transmitting the first sidelink HARQ feedback information to the base station.
19. The wireless user device of claim 13 , wherein the one or more parameters indicate one or more timing offset values associated with available timing offsets between the first time interval and the second time interval, and
wherein a bitwidth of the first indicator field is determined based on a quantity of the one or more timing offset values.