Patent ID: 9559762
Date: 2017-01-31
CPC Classifications: H04B

Claim:
1. A method of transmitting feedback information to a network entity by a base station supporting multi-user multi-input multi-output (MU-MIMO), the method comprising: measuring channel information for multiple channels between antennas of the base station and each of user equipments; obtaining a projection matrix based on the measured channel information; projecting one of the channel information or uplink data received from the user equipments to a second space from a first space using the projection matrix; and transmitting feedback information containing one of the projected channel information or the projected uplink data to the network entity; receiving, from the network entity, downlink data for the user equipments on which a precoding is performed based on a predetermined transmit power, wherein the predetermined transmit power is determined based on the feedback information, wherein the first space corresponds to a complex space, the second space corresponds to a real number space and a size of the channel information or a size of the uplink data projected to the second space is reduced after the channel information or the uplink data is projected.