Patent ID: 8774303

Claim:
A wireless communication apparatus comprising: an orthogonal polarization antenna configured to receive at least one reference signal; a channel state estimator configured to estimate a wireless polarization channel on the basis of the reference signal; and a transmission polarization state (TPS) selector configured to select a TPS corresponding to the estimated wireless polarization channel from among a plurality of M predefined TPSs, and feed back an index into the plurality of predefined TPSs on the selected TPS, wherein a TPS comprises complex-number weights for determining sizes and phases of at least two orthogonal polarization signals, and further wherein the TPS selector selects a TPS enabling downlink transmission power or a data transmission rate to be a maximum as denoted by { m k , χ b } = arg ⁢ ⁢ max χ ∈ { - , ⊥ } , m ∈ { 1 , 2 , … , M } ⁢  H k ⁢ p m χ  2 where m k , denotes a preferred matrix index that includes a TPS selected by a k th wireless communication apparatus, X k denotes a preferred polarization index selected by the k th wireless communication apparatus, and where an optimal TPS “p m k ” is equivalent to a vector closest to a largest singular vector “v k ” of a polarization channel matrix “H k ” being selected from the plurality of predefined TPSs.