Techniques are described for wireless communication. A method for wireless communication at a user equipment (UE) includes transmitting precoder selection signals from at least two antennas of the UE during performance of a random access procedure over a wireless network; and receiving, from the wireless network during the random access procedure, an indication of a refined precoding setting for the UE. A method for wireless communication at a network access device includes receiving, from a UE during a random access procedure performed by the UE, precoder selection signals from at least two antennas of the UE; identifying a refined precoding setting for the UE based at least in part on the received precoder selection signals; and transmitting an indication of the refined precoding setting to the UE.