Beamforming is a function that weights the signals to be transmitted, generating narrow beams towards UEs.
5G Beamforming is supported by NR sub-6 GHz downlink channels by default. It generates narrower beams, directs beams more accurately towards UEs, and delivers better coverage performance
5G Downlink beamforming procedure:
- Channel correction: It ensures the reciprocity of TX and RX channels and the consistency between channels.
- Weight calculation: The gNodeB calculates weight vectors based on downlink channel characteristics for adjusting the shapes and directions of beams.
- Weighting: The BBP adds the weight vectors and the to-be-transmitted data vectors for changing the amplitudes and phases of signals.
- Beamforming implementation: It adjusts the widths and directions of beams using the interference principles.