Digital predistortion of signals
AssigneeApple Inc.
InventorsAndreas Langer, Christoph Hepp, Andreas Menkhoff, Gunther Kraut
Life of this patent
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Abstract
Systems, circuitries, and methods for predistorting a digital signal in a transmit chain based on a predistortion function are provided. A method includes shifting a center frequency of an input signal by an offset to generate an adapted signal; predistorting the adapted signal based on a predistortion function to generate a predistorted adapted signal; reverting the shifting of the center frequency of the predistorted adapted signal by the offset to generate a predistorted signal; and causing transmission of the predistorted signal by a transmit chain.
Claims8
A method, comprising:
- receiving an input signal to a transmit chain;
- scaling the input signal by a first value to generate an adapted signal, the first value being selected based on a gain setting of a post predistortion gain block in the transmit chain;
- predistorting the adapted signal based on a predistortion function to generate a predistorted adapted signal;
- scaling the predistorted adapted signal by a reciprocal of the first value to generate a predistorted signal;
- and
- causing transmission of the predistorted signal by the transmit chain.
A baseband processor configured to:
- receive an input signal to a transmit chain;
- scale the input signal by a first value to generate an adapted signal, the first value being selected based on a gain setting of a post predistortion gain block in the transmit chain;
- predistort the adapted signal based on a predistortion function to generate a predistorted adapted signal;
- scale the predistorted adapted signal by a reciprocal of the first value to generate a predistorted signal;
- and
- cause transmission of the predistorted signal by the transmit chain.
Dependencies are inferred from the claim text.