ission techniques with beamforming at both gNB and UE can be used. To establish such highly directional transmission links, fine alignment of the transmitter and receiver beam pairs is required. Such beam alignment in NR is achieved through a set of operations denoted beam management procedures, which include Tx/Rx beam pair acquisition, beam measurement and reporting, and beam indication for the transmission. In beam acquisi- tion, a UE finds one or more Tx/Rx pairs of beams that can be used for subsequent commu- nication, based on the transmitted beamformed reference signals (e.g. SS/PBCH, CSI-RS) from gNB (see Figure 3.5.16). The UE measures the link quality for the corresponding beam pairs using L1-RSRP (3GPP TS 38.215) and reports the measurement results along with the selected index of the beamformed reference signal back to the gNB. Based on the reported information, the gNB assigns a transmission beam to a physical channel (PDSCH or PDCCH) or other reference signal by using the beam indication pro- cedure. The indication of the used beam is supported through quasi colocation signaling (3GPP TS 38.214), which establishes the connection between antenna ports with respect to the spatial channel properties. In particular, the antenna port of the reference signal used for beam management, for example, SS/PBCH or CSI-RS, can be quasi colocated with the antenna port of the corresponding physical channel, for example, PDCCH, PDSCH, or other reference signal (see Figure 3.5.17). For example, the antenna port of PDCCH Figure 3.5.17 Beam indication for the physical channel. Beam indication Index of the selected reference signal (beam) 3 5G System Overview can be associated with the antenna port of one of the beamformed reference signals (SS/PBCH or CSI-RS) by using the index of the corresponding reference signal. Based on the corresponding quasi colocation association, the beam obtained by the UE during beam pair acquisition can be used for PDCCH reception. A similar principle is also used for PDSCH transmission, wh