Downlink reference timing determination for physical random access channel in multiple transmission reception point communications

An apparatus for wireless communication at a user equipment (UE), comprising:

• memory;
• a transceiver;
• and
• at least one processor of a user equipment (UE), the at least one processor coupled with the memory and the transceiver and configured to:
• determine two downlink reference timings for an uplink transmission within at least one serving cell, wherein two timing advance groups each associated with a respective timing advance offset are configured for the at least one serving cell, and wherein each of the two downlink reference timings is associated with a respective timing advance group of the two timing advance groups;
• determine an uplink timing for a random access preamble of a physical random access channel (PRACH) or a message A of a physical uplink shared channel (PUSCH) based at least in part on at least one of the two timing advance offsets, at least one of the two downlink reference timings, or any combination thereof;
• and
• transmit, via the transceiver, as part of a random access procedure, the random access preamble in a valid PRACH occasion or the message A in a valid PUSCH occasion in accordance with the determined uplink timing.

A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE), the code comprising instructions executable by a processor to:

• determine two downlink reference timings for an uplink transmission within at least one serving cell, wherein two timing advance groups each associated with a respective timing advance offset are configured for the at least one serving cell, and wherein each of the two downlink reference timings is associated with a respective timing advance group of the two timing advance groups;
• determine an uplink timing for a random access preamble of a physical random access channel (PRACH) or a message A of a physical uplink shared channel (PUSCH) based at least in part on at least one of the two timing advance offsets, at least one of the two downlink reference timings, or any combination thereof;
• and
• transmit, as part of a random access procedure, the random access preamble in a valid PRACH occasion or the message A in a valid PUSCH occasion in accordance with the determined uplink timing.