1. A method for designing a Multiple User Multiple Input Multiple Output (MU-MIMO) codebook by a base station, terminal, or computer, the method comprising: generating or receiving feedback information transmitted in response to a pilot signal; analyzing beam patterns of candidate vectors included in a predetermined candidate codebook; and eliminating at least one of the candidate vectors based on the beam patterns of the candidate vectors to generate the MU-MIMO codebook for a MU-MIMO system being comprised of the remaining vectors.