Patent ID: 9432099
Filing Date: 2016-08-30
CPC Classification: H04B,H04L

Claim Text:
1. A method for reporting channel state information (CSI) from a user equipment (UE) in a wireless communication system, the method comprising: receiving a channel state information-reference signal (CSI-RS) by the UE based on CSI-RS configuration information provided by a base station; and determining a CSI based on the CSI-RS by the UE, reporting the determined CSI to the base station by the UE, wherein the determined CSI includes precoding information selected from a predetermined codebook, wherein elements of the predetermined codebook are configured based on a precoding vector when the CSI is a CSI of a 2 dimensional (2D) antenna structure, W1 is a precoding vector applied to a first linear antenna group of the 2D antenna structure, W2 is a precoding vector applied to a second linear antenna group of the 2D antenna structure, and wherein “a” is a value representing phase difference between the first linear antenna group and the second linear antenna group, wherein the W2 is obtained by modifying the W1.