US Patent 8385968 Precoding method and apparatus, and precoding control method and apparatus

To control precoding of a terminal in a serving base station, a first codeword that maximizes transmission power of the serving base station is determined by a codebook, and an index of a second codeword that minimizes interference to the neighboring base station is transmitted from the neighboring base station. The serving base station transmits an index of the first codeword, an index of the second codeword, and a combination ratio of a precoding matrix corresponding to the index of the first codeword and a precoding matrix corresponding to the index of the second codeword to the terminal.