Patent ID: 8718175

Claim:
A method of reporting at least one channel quality indicator from a receiver to a transmitter, the method comprising operations implemented at the receiver of: receiving one or more data streams transmitted by the transmitter in a Multiple-Input Multiple-Output system, wherein the data streams are processed by the transmitter using a transmission precoding matrix W prior to transmission of the data streams to the receiver; estimating a preferred precoding matrix W p which is preferred by the receiver; processing the received data streams with a signal processing module using the transmission precoding matrix W, such that the effective channel G at the output of the signal processing module is dependent upon the transmission precoding matrix W used by the transmitter; determining a second effective channel G p which is based on the preferred precoding matrix W p by: (i) determining a relationship between the effective channel G and the second effective channel G p based on the transmission precoding matrix W and the preferred precoding matrix W p ; and (ii) using the determined relationship and the effective channel G at the output of the signal processing module to determine the second effective channel G p ; using the determined second effective channel G p to determine the at least one channel quality indicator; and transmitting the determined at least one channel quality indicator to the transmitter.