Patent ID: 8665975
Filing Date: 2014-03-04
Classification: H04B

Abstract:
1. A method for receiving data in a Multi Input Multi Output (MIMO) system, the method comprising: decoding data received from a transmitter by using one beam-forming vector included in a codebook that beam-forming vectors are formed in a hierarchical structure according to at least one of change directions of radio channels, the number of change directions, and a change rate; determining whether to update the beam-forming vector based on a change of the radio channel; selecting other beam-forming vector included in the codebook having a hierarchical structure when it is determined that update for the beam-forming vector is required; feed-backing information about an index indicating where the selected beam-forming vector is located in the hierarchical structure of the codebook to the transmitter; and decoding data received from the transmitter by using the selected beam-forming vector; wherein the hierarchical structure of the codebook is implemented such that each layer of at least two layers of the codebook has a different channel change direction.