Patent ID: 8223855

Claim:
A method comprising: receiving at a mobile station a common reference signal and user specific information and determining the user specific information using known possible modulation constellations and known candidates of user specific information by minimizing an objective function for all known possible modulation constellations and known candidates of precoding matrix index (PMI) to determine the PMI corresponding to data or control information and wherein the objective function is given by y ^ = arg ⁢ ⁢ min 1 ≤ k ≤ K ⁢ ∑ i = 1 L ⁢ ( min 1 ≤ m r ≤ M 1 ≤ r ≤ R ⁢ ∑ g = 1 G ⁢  X i , g - ∑ r = 1 R ⁢ ∑ j = 1 N ⁢ w kj , r ( R ) ⁢ H ^ ij , g ⁢ c m r  2 ) where ŷ represents the determined PMI, X represents the received user specific information, w represents the known candidates for the PMIs, Ĥ represents a channel response estimated from the common reference signal in a given frequency domain, c represents the known modulation constellation, K represents a number of precoding vectors in the PMI, L represents a number of sub-carriers, M represents the total of known modulation constellations and m r represents the available modulation constellations for each rank, N represents a number of transmit antennas used for the common reference signal, R represents a rank for at least one of a data and control signal and G represents a number of receive antennas.