Method and system for digital-analog hybrid beamforming in millimeter wave downlink channel

Abstract

Disclosed is a method and system for digital-analog hybrid beamforming in a millimeter wave downlink channel. A hybrid beamforming method in a downlink channel with respect to at least one user terminal belonging to a transmission apparatus includes receiving feedback information from each of the at least one user terminal; selecting at least one user terminal for transmitting a transmission signal based on the received feedback information; performing digital beamforming with respect to the selected at least one user terminal; and performing analog beamforming with respect to the selected at least one user terminal based on a prestored codebook. The codebook includes a desired number of subsets calculated based on a number of transmit antennas and a number of radio frequency (RF) chains, and each of the subsets includes a number of beamforming vectors corresponding to the number of RF chains