Patent ID: 8254998

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 comprising codebook entries V in the form V = [ v 1 , Φ ⁡ ( v 1 1 ) ⁢ HH ⁡ ( v 1 Φ ⁡ ( v 1 1 ) - e 1 M ) ⁡ [ 0 v 2 ] , ⁢ Φ ⁡ ( v 1 1 ) ⁢ HH ⁡ ( v 1 Φ ⁡ ( v 1 1 ) - e 1 M ) ⁡ [ 0 Φ ⁡ ( v 1 2 ) ⁢ HH ⁡ ( v 2 Φ ⁡ ( v 1 2 ) - e 1 M - 1 ) ⁡ [ 0 v 3 ] ] ] , … where the remote transmitter has M=2 antennas, e 1 N =[1, 0, . . . , 0] T εC N (N=M, M−1, . . . ), C N being N-dimensional complex space, ν a denotes a column vector, ν b a denotes the b th element of the vector ν a , Φ ⁡ ( v b a ) = v b a  v b a  , ⁢ HH ⁡ ( w ) = { I - 2 ⁢ ww H  w  2 if ⁢ ⁢ w ≠ 0 I if ⁢ ⁢ w = 0 is the house-holder transformation of the vector w and ν a is selected from a set V a where V 1 =1/√{square root over (2)}{[1,1] T , [1,−1] T , [1,−j] T }, wherein j=√{square root over (−1)}, and V 2 ={e 1 1 }; and providing the feedback information to the remote transmitter.