Patent ID: 8781020

Claim:
A method of providing forward channel matrix information within a communication system, the communication system having i) a first communication device having a first plurality of antennas and ii) a second communication device having a second plurality of antennas, the method comprising: determining, at the second communication device, a channel estimation matrix H describing a forward channel in which a signal travels from the first communication device to the second communication device; performing, at the second communication device, QR decomposition on the channel estimation matrix H to derive a unitary matrix Q and an upper triangular matrix R, such that H=QR; transmitting, from the second communication device to the first communication device, only a portion of the upper triangular matrix R so that the first communication device can use the portion of the upper triangular matrix R to precode signals to be transmitted by the first communication device; and further comprising either: (a) quantizing matrix elements of the upper triangular matrix R to derive quantized matrix elements; and encoding the quantized matrix elements with error correcting codes; wherein transmitting only the portion of the upper triangular matrix R comprises transmitting, from the second communication device to the first communication device, the encoded quantized matrix elements, or (b) further comprising normalizing matrix elements of the upper triangular matrix by a standard deviation of noise in the forward channel determined from a signal-to-noise calculation; wherein transmitting only the portion of the upper triangular matrix R comprises transmitting, from the second communication device to the first communication device, all normalized diagonal and upper-diagonal matrix elements of the upper triangular matrix.