Patent ID: 8737507
Filing Date: 2014-05-27
Classification: H04B,H04L

Abstract:
1. A method of transmitting one or more data streams to a mobile terminal from a plurality of transmit antennas, the method comprising: assigning each of a plurality reference signals to a corresponding one of two or more antenna groupings, wherein at least a first one of the antenna groupings comprises two or more transmit antennas; transmitting each of the reference signals using at least one transmit antenna from the corresponding antenna grouping; receiving channel feedback data derived by the mobile terminal from the reference signals, wherein the channel feedback data comprises an indicator corresponding to a recommended precoder matrix selected by the mobile terminal; determining a first beam-forming vector for the first one of the antenna groupings; and mapping the one or more data streams to the transmit antennas according to a final precoding matrix that depends on the channel feedback data and the first beam-forming vector, to obtain a weighted transmit signal for each of the transmit antennas; wherein the mapping the one or more data streams to the transmit antennas comprises computing the final precoding matrix by calculating the Kronecker product of the recommended precoder matrix and the beam-forming vector.