Patent ID: 7904039

Claim:
An array receiver for processing signals received from a plurality (M+1) of co-channel transmitting users via an array antenna having an array of (N) antenna elements to obtain a set of user-specific estimated received signals (z 0 , . . . , z M ) each corresponding to a respective one of said transmitting users, said array receiver having: radio frequency units ( 26 / 1 , . . . , 26 /N) for conversion of signals from the array antenna to provide a corresponding set of (N) antenna element signals (x 1 , x 2 , . . . , x N ), respectively, where N is at least equal to the number (M+1) of transmitting users, each of the antenna element signals (x 1 , x 2 , . . . , x N ) comprising information from each of the plurality (M+1) of transmitting users, a common preprocessing section ( 40 ) for receiving and processing the (N) antenna element signals (x 1 , x 2 , . . . , x N ) from the radio frequency units ( 26 / 1 . . . 26 /M) to provide a plurality (M+1) of basis signals (y 0 , . . . , y M ), and a plurality (M+1) of signal processing units ( 60 0 , . . . , 60 M ) each for processing said basis signals (y 0 , . . . , y M ) to provide a respective one of said user-specific estimated received signals (z 0 , . . . , z M ), wherein the common preprocessing section ( 40 ) comprises filtering means ( 40 / 1 , . . . , 40 /M) for sampling each of the (N) antenna element signals (x 1 , x 2 , . . . , x N ) and combining resulting samples of at least some of said antenna element signals (x 1 , x 2 , . . . , x N ) to provide said plurality of (M+1) basis signals (y 0 . . . , y M ), each of the basis signals (y 0 , . . . , y M ) comprising a different combination of the antenna element signals (x 1 , x 2 , . . . , x N ) and having μ dimensions spanning a dominant subspace containing most of the energy from a respective one of the transmitted user signals, said (M+1) basis signals (y 0 , . . . , y M ) together having fewer space-time dimensions (μx(M+1)) than the space-time dimensions (N×L) of the (N) combined antenna element signals (x 1 , x 2 , . . . , x N ), where L is the maximum length of the channel impulse response in symbol periods, and updating means for periodically updating parameters of the filtering means ( 40 / 1 , . . . , 40 /M) used for deriving each particular basis signal such that each of the user-specific estimated received signals (z 0 , z 1 , . . . z M ) will exhibit a desired optimized concentration of energy; and wherein each of said signal processing units ( 60 0 , . . . , 60 M ) has a plurality of inputs coupled to the common preprocessing section ( 40 ) for receiving therefrom all of the (M+1) basis signals (y 0 , . . . , y M ), and is adapted for processing and combining at least some of said (M+1) basis signals (y 0 , . . . , y M ) to produce a respective one of said set of user-specific estimated received signals (z 0 , . . . , z M ) for a corresponding desired one of the plurality (M+1) of transmitting users.