Patent ID: 8477872

Claim:
A method for transmitting information in a multi-antenna system, comprising: receiving, by a transmitting end, information which comprises information of an index of a precoder transmitted by a receiving end; selecting, by the transmitting end, a precoder from a dual-level codebook based on the information of the index of the precoder, and precoding to-be-transmitted data by using the precoder; and transmitting, by the transmitting end, the precoded data to the receiving end; wherein at least one precoder c in the dual-level codebook satisfies: c = [ [ 1 φ m , 1 ] ⊗ w ⁡ ( : , 1 ) ⁡ [ 1 φ m , 2 ] ⊗ w ⁡ ( : , 2 ) ⁢ ⁢ ⋯ ⁢ [ 1 φ m , N ] ⊗ w ⁡ ( : , N ) ] , wherein w is a N T /2×N matrix, [ 1 1 ⋯ 1 φ m , 1 φ m , 2 ⋯ φ m , N ] is a 2×N matrix, N T is the number of transmit antennas, N is Rank, φ m,n denotes a complex number, denotes a Kronecker tensor product of matrices, w(:,n) denotes the n'th column of matrix w, and n=1, . . . , N.