Patent ID: 8116702

Claim:
A transmitter ( 2 ) having multiple transmit antennas ( 3 1 , 3 M-1 , 3 M ) for transmission over a communication channel ( 6 ) to receivers ( 4 1 , 4 K-1 , 4 K ) each having one or more receive antennas ( 5 1,1 , 5 K-1, N-1 , 5 K, N ), the transmitter ( 2 ) comprising: means ( 9 ) for estimating channel conditions for the channel ( 6 ); a feedbackward filter stage ( 14 1 , 14 K-1 ) for filtering signals representing data intended to be communicated to respective receivers ( 4 1 , 4 K-1 , 4 K ) with a feedbackward filter before transmission over the channel ( 6 ) to compensate for expected co-signal interference in the channel ( 6 ); a beamforming stage ( 13 ) for allocating powers at which the filtered signals are combined at each transmit antenna ( 3 1 , 3 M-1 , 3 M ) for transmission over the channel ( 6 ); means ( 8 ) for transmitting information representing a feedforward filter to one of the receivers ( 4 1 , 4 K-1 , 4 K ) for application to a signal received over the channel ( 6 ) at one or more receive antennas ( 5 1,1 , 5 K-1, N-1 , 5 K, N ) of that receiver ( 4 1 , 4 K-1 , 4 K ) to extract from the received signal a signal representing the data intended to be communicated to that receiver ( 4 1 , 4 K-1 , 4 K ) without knowledge of the signal or signals received over the channel ( 6 ) at the receive antenna(s) ( 5 1,1 , 5 K-1, N-1 , 5 K, N ) of the other receiver(s) ( 4 1 , 4 K-1 , 4 K ); and means ( 9 ) for determining the feedbackward filter, power allocation and feedforward filter based on the estimated channel conditions for the channel ( 6 ).