Motorola Corporation

Robert Louis Palandech

George Francis Opas

Andrew Merritt Khan

Lawrence Edwin Connell

Pallab Midya

Steven F Gillig

James E Mitzlaff

John K Grosspietsch

Wayne H Bradley

An adaptive predistortion linearization system includes input path digital-to-analog converters (DACs), error path DACs, a digital signal processor, and a radio frequency (RF) combiner. The digital signal processor includes a look-up table storing complex gain coefficient values. The digital signal processor generates an error signal based on the complex input signal and the complex gain coefficients by using a vector decomposition calculation. Feedback from a power amplifier can be provided to a training algorithm for periodically updating the gain coefficient values stored in the look-up table. By performing separate D/A conversions, the error path and input signals can be separately filtered. This separation also permits the error signal to be decoupled from the complex input signal, which facilitates an improvement in the wide-frequency-offset noise performance of the system.

Amplifier predistortion system and method

A method (200) and device (100) provide an efficient linear power amplifier that generates a variable-envelope radio frequency RF signal. The method includes the steps of: A) using an efficient envelope-following unit to output a supply voltage in accordance with a variable envelope of an input baseband signal, wherein using the efficient envelope-following unit includes: 1) using a bandwidth-limiting mapping unit to determine a reference signal based on the baseband signal; and 2) using an envelope-tracking power converter to output a supply voltage, responsive to the reference signal, to the linear RF power amplifier; B) providing an RF input signal with amplitude and phase information to a linear RF power amplifier; and C) using the linear RF power amplifier to output a power-efficient amplified variable-envelope RF signal with substantially a same amplitude and phase information as the RF input signal.

Method, device, phone and base station for providing envelope-following

The present invention provides an apparatus (200) and method (500) for providing a baseband digital error signal in an adaptive predistorter. A carrier cancellation circuit (202) provides a difference (212) between a first signal (208) based on an amplifier output and second signal (210) based on a data input. A quadrature demodulator (204) provides a baseband analog error signal (214) based on the difference (212). An analog-to-digital converter (206) provides the baseband digital error signal (216) based on the baseband analog error signal (214).

Apparatus and method for providing a baseband digital error signal in an

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Sunrise, FL, United States of America

Robert Louis Palandech