Patent ID: 9608701
Date: 2017-03-28
CPC Classifications: H04B

Claim:
1. An apparatus for transmitting signals, the apparatus comprising: at least one processor; a memory; and a radio frequency unit, by executing at least one program stored in the memory, wherein the at least one processor selects at least one array of a plurality of arrays connected to the apparatus based on a spatial covariance matrix of an uplink from a terminal to the plurality of arrays, wherein the spatial covariance matrix ensures channel reciprocity at downlink from the plurality of arrays to the terminal, and forms a transmission beam to be transmitted to the terminal through the at least one selected array, wherein the plurality of arrays include at least one base station (BS) antenna, respectively, and wherein when selecting the at least one array, the at least one processor estimates the spatial covariance matrix based on a pilot signal to be transmitted to the terminal; determines a selection index to select the at least one array based on the estimated spatial covariance matrix; and selects the at least one array based on the selection index.