Wide bandwidth digital predistortion system with reduced sampling rate

Abstract

A digital predistortion linearization method is provided for increasing the instantaneous or operational bandwidth for RF power amplifiers employed in wideband communication systems. Embodiments of the present invention provide a method of increasing DPD linearization bandwidth using a feedback filter integrated into existing digital platforms for multi-channel wideband wireless transmitters. An embodiment of the present invention utilizes a DPD feedback signal in conjunction with a low power band-pass filter in the DPD feedback path.

What is claimed is: 
     
         1 . A method comprising:
 receiving an input signal at a digital predistorter (DPD);   introducing predistortion to the input signal using the DPD to generate a predistorted input signal;   filtering the predistorted input signal using a digital filter to generate a filtered input signal, wherein the predistorted input signal is filtered over a filter bandwidth less than a DPD bandwidth;   amplifying the filtered input signal to generate an amplified signal; and   filtering at least a portion of the amplified signal using a band-pass filter to generate a filtered feedback signal.