Techniques for random access channel (RACH) enhancements for new radio unlicensed (NR-U) communications

An apparatus for wireless communication, comprising:

• a transceiver;
• a memory configured to store instructions;
• and
• at least one processor communicatively coupled with the transceiver and the memory, wherein the at least one processor is configured to:
• perform a first listen-before-talk (LBT) procedure for a physical random access channel (PRACH) transmission of a Message A transmission in a two-step random access channel (RACH) procedure and a second LBT procedure for a physical uplink shared channel (PUSCH) transmission of the Message A transmission in the two-step RACH procedure;
• increment a power ramping counter associated with a common power ramping for both the PRACH and the PUSCH transmissions;
• identify a success of the first LBT procedure for the PRACH transmission;
• transmit the PRACH transmission over a PRACH resource based on identifying success of the first LBT procedure;
• identify a failure of the second LBT procedure for the PUSCH transmission;
• perform a PUSCH transmission attempt at a subsequent PUSCH resource of multiple PUSCH transmission opportunities singularly associated to the PRACH resource, based on identifying the failure of the second LBT procedure for the PUSCH transmission;
• identify a failure of all LBT procedures for the PUSCH transmission;
• receive one or both of a fallback random access response (RAR) or a second message of two-step RACH procedure associated with identifying the failure of all LBT procedures for the PUSCH transmission;
• identify whether a power ramping parameter for the PRACH transmission is different from a power ramping parameter for the PUSCH transmission;
• forgo power ramping for the PUSCH transmission associated with identifying that the power ramping parameter for the PRACH transmission is different from the power ramping parameter for the PUSCH transmission;
• and
• perform the power ramping for the PUSCH transmission associated with identifying that the power ramping parameter for the PRACH transmission is not different from the power ramping parameter for the PUSCH transmission.