APPARATUS AND METHOD FOR CODEBOOK BASED COOPERATIVE BEAMFORMAING IN BORADBAND WIRELESS ACCESS COMMUNICATION SYSTEM

摘要

A codebook-based cooperative beamforming device in a broadband wireless access communication system and a method therefore are provided to increase performance by feeding back a limited amount of information based on a codebook, thereby offering similar performance to a time when perfect channel information exists even though limited information is used. A signal is received from a cooperative node(410). A beamforming vector for making an SNR(Signal to Noise Ratio) maximum is calculated(420,430). A codebook index corresponding to the beamforming vector is selected(440). The codebook index is transmitted to the cooperative node through a feedback channel(450). The received signal is the same as a mathematical formula 7(x=Z.sup.H.Hws+Z.sup.H.n, here, n is an iid(Independent Identically Distributed) complex number AWGN(Additive White Gaussian Noise) vector, H is a channel matrix, Z is a combining vector, w is a beamforming vector, and x is a receiving signal vector).