Patent ID: 8354884

Claim:
An adaptive predistortion linearized amplifier system, comprising: an input receiving a time varying communication signal; a first signal path coupled to the input, comprising: a predistorter coupled to the input and performing a predistortion operation on the time varying communication signal using predistortion coefficients and providing a predistorted signal; an amplifier receiving and amplifying the predistorted signal and providing an amplified signal; an output coupled to the power amplifier and providing the amplified signal as an output signal; a measurement circuit coupled to sample the output signal for providing an error signal envelope signal; a second signal path coupled to the input, comprising a sampling circuit receiving the time varying communication signal and asynchronously sampling the time varying communication signal; a demodulating circuit configured to derive a demodulated error signal related to nonlinearities of the amplifier based on the error signal and a signal derived from the sampled time varying communication signal; a computing circuit configured for computing the sampled signal instantaneous phase based on the sampled input signals; an accumulating circuit configured for calculating and storing moments; and at least one demodulating circuit configured to perform a digital Fourier Transformation on the moments to yield demodulated values; and, a coefficient calculator configured for using the demodulated error signal to adapt the predistorter coefficients.