Patent ID: 8477867

Claim:
A method of configuring a multi-cell precoding matrix for a multiple input multiple output (MIMO) operation in a wireless communication system in which a plurality of base stations participate in cooperative communication, the method comprising: configuring the multi-cell precoding matrix using one or more single-cell precoding matrices, wherein coefficients to be multiplied by the single-cell precoding matrices satisfy a condition in which the product between the multi-cell precoding matrix and a Hermitian matrix of the multi-cell precoding matrix is a unitary matrix, wherein the multi-cell precoding matrix is configured by assigning a same single-cell precoding matrix in a row direction or a column direction of the multi-cell precoding matrix, and wherein the multi-cell precoding matrix is obtained according to Equation (E-1) and Equation (E-2): W co C = 1 C ⁡ [ a 11 ⁢ W p a 12 ⁢ W p ⋯ a 1 ⁢ C ⁢ W p a 21 ⁢ W q a 22 ⁢ W q ⋯ a 2 ⁢ C ⁢ W q ⋮ ⋮ ⋮ ⋮ a C ⁢ ⁢ 1 ⁢ W r a C ⁢ ⁢ 2 ⁢ W r ⋯ a CC ⁢ W r ] ⁢ ⁢ or ⁢ ⁢ W co C = 1 C ⁡ [ a 11 ⁢ W p a 12 ⁢ W q ⋯ a 1 ⁢ C ⁢ W r a 21 ⁢ W p a 22 ⁢ W q ⋯ a 2 ⁢ C ⁢ W r ⋮ ⋮ ⋮ ⋮ a C ⁢ ⁢ 1 ⁢ W p a C ⁢ ⁢ 2 ⁢ W q ⋯ a CC ⁢ W r ] , ⁢ and ( E ⁢ - ⁢ 1 ) a mn = exp ⁡ ( j ⁢ 2 ⁢ π ⁡ ( m - 1 ) ⁢ ( n - 1 ) C ) , ( E ⁢ - ⁢ 2 ) where W p , W q , . . . , W r each denotes a single-cell precoding matrix, and a mn is any value satisfying W co H ·W co =I C×L , wherein W co H is a Hermitian matrix of W co , m=1, 2, . . . , C, and where C is the number of base stations, n=1, 2, . . . , C, and I C×L is a C×L unitary matrix).