Patent attributes
A first precoding matrix W1 is selected from a first codebook comprising sets of rank specific precoding matrices. The first codebook is characterized by there being fewer precoding matrices associated with higher ranks than associated with lower ranks, and characterized by precoding matrices associated with ranks above a certain rank all being diagonal matrices. The selected first precoding matrix W1 is used to select a rank-specific second precoding matrix W2 from a second codebook, such that the selected first and second precoding matrices form a joint precoder specific to a desired rank. The second codebook is characterized by differently sized precoding matrices associated with each of N total ranks, in which N is an integer greater than one. Information on the joint precoder is reported to a network node over an uplink transmission channel.
