Patent ID: 9264206
Filing Date: 2016-02-16
CPC Classification: H04B,H04L

Claim Text:
1. A method for transmitting a signal to a user equipment by a base station in a wireless communication system, comprising: generating randomly a first beamforming vector set for a first subframe; configuring a first random beamformer corresponding to the first subframe from the first beamforming vector set; transmitting a downlink signal to the user equipment in the first subframe using the first random beamformer; receiving information about a preferred beamforming vector from the user equipment; generating a second beamforming vector set for a second subframe based on the preferred beamforming vector; configuring a second random beamformer corresponding to the second subframe; and transmitting the downlink signal to the user equipment in the second subframe using the second random beamformer, wherein configuring the first random beamformer comprises: a) including a first beamforming vector into the first random beamformer by selecting randomly the first beamforming vector from the first beamforming vector set; b) including a second beamforming vector into the first random beamformer by selecting, from the first beamforming vector set, the second beamforming vector having the least correlation with one or more beamforming vectors included in the first random beamformer; and c) repeating the step b) until the beamforming vectors as much as a number of virtual antennas of the base station are included in the first random beamformer, wherein configuring the second random beamformer comprises: d) including a third beamforming vector into the second random beamformer by selecting randomly the third beamforming vector from the second beamforming vector set; e) including a fourth beamforming vector into the second random beamformer by selecting, from the second beamforming vector set, the fourth beamforming vector having the least correlation with one or more beamforming vectors included in the second random beamformer; and f) repeating the step e) until the beamforming vectors as much as the number of virtual antennas are included in the second random beamformer.