Receive assisted listen before talk with multiple candidate beams and waveform as single acknowledgment of pre-grant

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

• a memory storing computer-executable instructions;
• and
• at least one processor coupled to the memory and configured to execute the instructions to:
• receive a pre-grant (PG) indicating a plurality of beams;
• perform a listen before talk (LBT) procedure on each beam of the indicated plurality of beams;
• and
• transmit an acknowledgment to the pre-grant (APG) as a sounding reference signal (SRS) with a sequence that indicates that the LBT procedure for one or more of the indicated plurality of beams was successful, wherein to transmit the APG, the at least one processor is configured to execute the instructions to transmit the SRS via one or more transmission ports that are each associated with a different phase shift of the sequence and a successful LBT procedure.