Patent ID: 8315329

Claim:
A method implemented in a mobile terminal, comprising: generating feedback information for transmission in order for a remote transmitter to select a precoding matrix from a codebook for M=2 transmit antennas, the codebook having entries in the following form A ⁡ ( v 1 , v 2 , v 3 , … ) = [ v 1 , HH ⁡ ( v 1 - e 1 M ) ⁡ [ 0 v 2 ] , HH ⁡ ( v 1 - e 1 M ) ⁡ [ 0 HH ⁡ ( v 1 - e 1 M ) ⁡ [ 0 v 3 ] ] ] , … where e 1 N =[1, 0, . . . , 0] T εC N , C N being N-dimensional complex space, v a denotes a column vector, HH(v k −e 1 l ) is a rotation matrix that transforms vector v k to the unit vector e 1 l and v a is selected from a set V a where V 1 = 1 2 ⁢ { [ 1 , 1 ] T , [ 1 , - 1 ] T , [ 1 , j ] T , [ 1 , - j ] T } , j = - 1 , and ⁢ ⁢ V 2 = { e 1 1 } .