Method of determining physical sidelink feedback channel resource for hybrid automatic repeat request feedback and related device

A user equipment (UE) for determining one or more physical sidelink feedback channel (PSFCH) resources for hybrid automatic repeat request (HARQ) feedback, the UE comprising:

• at least one processor for executing computer-executable instructions;
• and
• at least one non-transitory machine-readable medium, coupled to the processor, for storing the computer-executable instructions, wherein the computer-executable instructions when executed by the at least one processor instruct the UE to:
• receive, from a second UE, first sidelink control information (SCI) for scheduling a first unicast physical sidelink shared channel (PSSCH) transmission, the first SCI associated with a source identifier (ID);
• receive, from the second UE, second SCI for scheduling a second unicast PSSCH transmission, the second SCI associated with the same source ID;
• determine priorities of a first HARQ feedback corresponding to the first PSSCH transmission and a second HARQ feedback corresponding to the second PSSCH transmission according, respectively, to the first SCI and the second SCI;
• and
• transmit, to the second UE, a PSFCH for at least one of the first HARQ feedback and the second HARQ feedback with a higher priority according to the determined priorities when a first PSFCH resource for the first HARQ feedback and a second PSFCH resource for the second HARQ feedback are at least partially overlapped in time domain, wherein transmitting the PSFCH comprises transmitting HARQ bits of both of the first and second HARQ feedbacks in the PSFCH when the PSFCH has enough resource size to include the HARQ bits of both of the first and second HARQ feedbacks in at least four slots after the first and second PSCCH transmissions.