Patent ID: 6774834
Filing Date: 2004-08-10
Classification: H03F

Abstract:
A method of preparing signals to be compared to establish predistortion at an input of an amplifier, the signals comprising a signal before amplification and a signal after amplification by said amplifier,wherein the method is characterized in that said preparation includes performing time alignment between the signal before amplification and the signal after amplification, prior to using said signals to establish said predistortion, wherein the method further comprises: a coarse time alignment step, in which the signal before amplification is subjected to a time-delay comprising an integer number of first time units and in which a value of the time-delay that produces a delayed signal before amplification having the best time alignment with the signal after amplification is determined, and a fine time alignment step, in which a delay or an advance value of a fraction of the first time unit to be applied to a sampled signal after amplification producing the best time alignment with the delayed signal before amplification is determined and in which that delay or advance value is applied to the signal after amplification, wherein the signal after amplification and the delayed signal before amplification time aligned in this way are used to establish said predistortion.