Patent ID: 7729446
Filing Date: 2010-06-01
Classification: H03F,H04L

Abstract:
1. A method for predistorting a signal for transmission to a non-linear element to linearize the response of the non-linear element, comprising: providing an input for receiving baseband signals to be transmitted to the non-linear element; providing a first digital predistortion block coupled to the input for adaptively modifying the received baseband signals to compensate for distortion effects of a first duration in the non-linear element, the first digital predistortion block comprising a plurality of parallel coupled memory blocks each comprising at least one programmable nonlinearity, at least one signal multiplier and at least one summer; providing a second digital predistortion block coupled to the first digital predistortion block and generating an output for transmission to the non-linear element, for further adaptively compensating for distortion effects in the non-linear element of a second duration shorter than the first duration, the second digital predistortion block comprising a generalized Nth order digital filter coupled to a linear equalizer, wherein N is greater than 0; providing a feedback path input for receiving an output of the non-linear element as feedback signals; coupling the feedback signals to a first capture buffer operable to capture and store signal samples collected from the feedback path input for observation; adapting parametric values within the first digital predistortion block in response to analysis of captured signals stored within the first capture buffer to linearize the output of the non-linear element; and adapting parametric values within the second digital predistortion block in response to analysis of captured signals stored within the first capture buffer to linearize the output of the non-linear element.