1. A method for generating a hybrid codebook for a Multi-User Multiple-input Multiple-Output (MU-MIMO) system, comprising: generating a parent matrix set including a plurality of M×M unitary matrices by a terminal, which is one of transmitter and receiver, when the number of transmitter antennas is M; and generating a child matrix set dependent on the parent matrix set by using training vectors included in a random training set and each column for each unitary matrix of the parent matrix set as an initial vector codebook by the terminal, wherein the transmitter derives channel quality information, at least in part, through manipulation of a child matrix selected from the child matrix set.