Table 1 UL MU beamforming approaches.
From: Downlink Assisted Uplink Zero Forcing for TDD Multiuser MIMO Systems
Method | UL signaling | DL signaling | Power and rate control |
|---|---|---|---|
Unquantized precoding | CSI sounding pilot | Beam allocation pilots | May be locally decided by terminal |
Quantized precoding | CSI sounding pilot | Precoder indexes and rate parameters | Signalled by BS |