Patent ID: 8055217

Claim:
A system comprising a Cartesian transmitter, wherein the transmitter comprises: a transmit chain configured to receive an input signal X having in-phase and quadrature components and having a pre-distorter configured to employ a first compensation lookup table operable to hold complex valued entries to carry out in-phase and quadrature pre-distortion with respect to the input signal to form a pre-distorted signal Z, and a nonlinear element configured to process pre-distorted signal Z to form an output signal Y; a receiver coupled to receive output signal Y and operable to provide a feedback signal in a feedback loop; an adaptive normalization mechanism operable receive the feedback signal and operable to produce an adaptively normalized feed back signal {tilde over (Y)}, using an adaptively updated complex gain normalization parameter; and a pre-distortion update module operable to update the at least one compensation lookup table based on the pre-distorted signal Z and the adaptively normalized feedback signal {tilde over (Y)}.