Beamforming of synchronization signals and broadcast channel information
Beamforming as a technology is not new, but with 5G, beamforming is not only applied to user-specific data streams but also to synchronization signals and broadcast channel information. Beamforming can be implemented with antenna arrays on the base station side, where different groups of antenna elements (dynamically allocated) form beams to different users depending on their phases and amplitudes related to each other.
Using beamforming also for synchronization signals and broadcast channel information provides better overall coverage thanks to the higher antenna gain. The synchronization signal block (SSB) in 5G NR can carry beam-specific information (SSB index). These SSB index “beams” are static and can be considered micro sectors, e.g. eight micro sectors in one macro sector for the 3.7 GHz case (see Figure 3).