DUAL LOOP DIGITAL PREDISTORTION FOR POWER AMPLIFIERS

摘要

A method of predistorting an input signal (902) for an amplifier is disclosed (FIG. 9). The method includes predistorting the input signal with a first set of parameters (FDPD) and a second set of parameters (CDPD) at a first time (904). The first set of parameters is updated at a second time (914). The second set of parameters is updated separately from the first set of parameters at a third time (920).

主权项

1. A transmitter circuit comprising:
a digital input lead coupled to a digital input signal; modulation circuitry having an input connected to the digital input lead and having a modulation output; crest factor reduction circuitry having an input connected to the modulation output and having an crest factor reduction output; digital predistortion circuitry having an input lead connected to the crest factor reduction output, the digital predistortion circuitry including:
first digital predistortion circuitry having a digital input coupled to the input lead, a parameter input receiving a first set of predistortion parameters, and a first predistorted digital output;second digital predistortion circuitry having a digital input coupled to the first digital output, a parameter input receiving a second set of predistortion parameters, and a second predistorted digital output;first adaption circuitry having a first error input and having a parameter output coupled with the parameter input of the first digital predistortion circuitry; andsecond adaption circuitry having a second error input and having a parameter output coupled with the parameter input of the second digital predistortion circuitry; digital to analog converter circuitry having an input connected to the second predistorted digital output and having an analog output; RF up converter circuitry having an input connected to the analog output and having a radio frequency output; power amplifier circuitry having a radio frequency input connected to the radio frequency output and having a transmitter output; attenuation circuitry having a transmitter input connected to the transmitter output and having an attenuated output; RF down converter circuitry having an attenuated input connected to the attenuated output and having an analog feedback signal output; post process circuitry having an analog feedback signal input connected to the analog feedback signal output and having a corrected feedback signal output connected with the first error input and with the second error input.