Method and apparatus for MSG-A transmission in two-step RACH

摘要

Methods and apparatus for beam refinement are disclosed. A wireless transmit/receive unit (WTRU) may be configured to receive configuration information. The configuration information may indicate an association between preambles, synchronization signal blocks (SSBs), reference signal (RS) sets, and physical uplink shared channel (PUSCH) resources. The WTRU may be configured to receive the plurality of SSBs, determine a measurement of the received SSBs, and select the SSB based on the determined measurement. The WTRU may be configured to select and transmit the preamble using the first beam. The WTRU may be configured to receive a plurality of sets of RSs based on the transmitted preamble and to determine a measurement of the received sets of RSs. The WTRU may be configured to select the RS based on the determined measurement of the received sets of RSs. The WTRU may be configured to transmit uplink data on PUSCH using the second beam.