FIELD: wireless communication.
SUBSTANCE: systems and methods are described for radio frequency (RF) calibration in a multi-user (MU) transmission system (MAS), in which the principle of reciprocity between uplink and downlink channels is applied. RF calibration is used to calculate precoding parameters for downlink without feedback based on estimates of uplink, which makes it possible to reduce costs for feedback when transmitting information on the state of the channel, as in circuits with feedback. For example, MU-MAS system in one design comprises wireless cellular network with one or multiple radio beacons, a plurality of client devices and a plurality of distributed antennae working together, using precoding methods to eliminate interference between clients and increase network throughput.
EFFECT: high spectral efficiency.
22 cl, 25 dwg
