Patent ID: 8380143

Claim:
A predistortion system for linearizing the output of a power amplifier comprising: a first receiver configured to receive a first signal representative of a radio frequency (RF) modulated signal; a second receiver configured to receive a feedback signal representative of at least one nonlinear characteristic of a power amplifier; a reference path communicatively coupled with the first receiver and a predistortion controller; a feedback path communicatively coupled with the second receiver and the predistortion controller; the predistortion controller comprising at least one lookup table of a predetermined size, wherein the lookup table comprises at least one correction value that falls within a range determined by the predetermined size of the table; and wherein the at least one lookup table is configured to: respond to inputs derived from the difference between squares of the in-phase and quadrature components, respectively, of the first signal and the feedback signal; store at least one time-delay value that compensates for a time delay between the reference path and the feedback path; adaptively update the at least one correction value in the table by combining both a non-linear correction value of the power amplifier and the at least one time-delay value; and wherein the controller is configured to generate a correction factor for correcting the nonlinear characteristics of the power amplifier, wherein the correction factor is based on the at least one correction value in the lookup table; and a processor, configured to: combine the RF modulated signal with a second signal corresponding to the correction factor; and supply the combined RF modulated signal with said second signal to the power amplifier to linearize the output of the power amplifier.