Patent ID: 8412132
Filing Date: 2013-04-02
Classification: H03F,H04B,H04L

Abstract:
1. An adaptive predistortion unit for a transmitter, comprising: an error signal unit having a first input configured to receive a delayed version of a baseband input signal, a second input configured to receive a power amplifier feedback signal from an output of a power amplifier, and an output configured to provide an input error signal that corresponds to a difference between the delayed version of the baseband input signal and the power amplifier feedback signal; a signal conditioner having an input configured to receive the input error signal and an output configured to provide an adjusted error signal that has a lower direct current offset than the input error signal; and a look-up table including multiple predistortion functions, wherein one of the multiple predistortion functions is selected based on the adjusted error signal to provide a function for multiplication with the baseband input signal.