Patent ID: 7035345
Filing Date: 2006-04-25
Classification: H03F

Abstract:
1. An adaptive method for predistorting an RF modulated signal, to be transmitted, supplied by a signal source to an input of a power amplifier having an output for delivering an amplified output signal, said method comprising the steps of: predistorting the RF modulated signal to be transmitted using an I/Q modulator interposed between the signal source and the input of the power amplifier, and controlled by means of amplitude and phase look-up tables stored in a distorting generator; producing, via a first digital receiver, a first feedback signal in response to the RF predistorted signal; producing, via a second digital receiver, a second feedback signal in response to the RF amplified output signal from the power amplifier; modeling the power amplifier in response to the first and second feedback signals; and updating the predistortion amplitude and phase look-up tables in response to said modeling of the power amplifier, wherein said second feedback signal includes the complex envelope of the RF amplified output signal, and wherein said modeling step includes the discrimination of the complex envelope of the first feedback signal referenced to the complex envelope of the second feedback signal to yield a predistortion function correlated to a behaviour of the power amplifier including nonlinearities and memory effects.