Patent ID: 8619904

Claim:
A method for providing a quantized representation of a precoding matrix for a codebook-based precoder, said precoder being operable for precoding information symbols for multi-antenna transmission from a transmitter to a receiver in a mobile communications network, said method comprising the steps of: estimating a channel matrix representing multi-antenna channel characteristics between said transmitter and said receiver in said mobile communications network, said transmitter having at least two antennas and said receiver having at least one antenna; performing an iterative vector selection procedure for iteratively selecting precoding vectors for said precoding matrix, wherein each of a number of iterations of said iterative vector selection procedure comprises the steps of: evaluating performance of each one of a set of candidate vectors included in a given vector codebook with respect to a predetermined performance measure that is dependent on the estimated channel matrix; and selecting one of said set of candidate vectors as a respective precoding vector for said precoding matrix based on the evaluated performance; and compiling information representative of a set of selected precoding vectors to form said quantized representation of said precoding matrix for transmission to said transmitter.