Patent ID: 8576776
Filing Date: 2013-11-05
Classification: H04B

Abstract:
1. A feedback method of a terminal in a Multiple Input Multiple Output (MIMO) wireless communication system, the feedback method comprising: feeding back, by a feedback transmitter, a long term Precoder Matrix Index (PMI) to a serving base station under direction of the serving base station when the long term PMI feedback transmission is required; generating, by a controller, a new codebook using the long term PMI; determining, by the controller, a short term PMI from the new codebook; and feeding back, by the feedback transmitter, the short term PMI to the serving base station, wherein the long term PMI feedback transmission is required when a transmit correlation matrix is determined from a reference signal received from the serving base station and a ratio of two greatest eigenvalues in the transmit correlation matrix exceeds a threshold.