Rach conveyance of DL synchronization beam information for various DL-UL correspondence states

A method for wireless communication at a base station, comprising:

• transmitting a downlink (DL) signal to a user equipment (UE) on one or more DL beams of the base station;
• receiving, on at least one of a resource or a random access channel (RACH) waveform, a RACH message from the UE on a plurality of uplink (UL) beams, wherein the at least one of the resource or RACH waveform are based at least in part on a nature of beam correspondence between at least one of the UL beams at the UE and one or more receive beams at the UE, and wherein the resource or the RACH waveform of the RACH message conveys the nature of beam correspondence;
• identifying, based at least in part on the resource or the RACH waveform, a selected DL beam of the one or more DL beams for communications from the base station to the UE;
• and
• transmitting one or more subsequent messages to the UE using the selected DL beam.

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

• a processor, memory coupled with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• receive a downlink (DL) signal from a base station on one or more DL beams of the base station;
• identify a nature of beam correspondence between one or more receive beams at the UE and one or more transmit beams at the UE;
• identify a selected DL beam of the one or more DL beams of the base station for communications from the base station to the UE;
• and
• transmit, to the base station, a message indicating the nature of beam correspondence, wherein the message is transmitted based at least in part on the selected DL beam of the base station and the nature of beam correspondence between one or more receive beams at the UE and one or more transmit beams at the UE.