Pre-Distortion Pattern Recognition for Nonlinear Power Amplifiers

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Solution Overview

Problem

Power amplifiers often operate non-linearly, causing distortion in both amplitude and phase of amplified signals, which can lead to energy inefficiency and errors, especially in systems lacking access to undistorted signals for pre-distortion calculations.

Innovation Solution

A system and method for pre-distortion pattern recognition that includes a pre-distorter design block capable of identifying distortion from a finite set of symbols, allowing for dynamic pre-distortion calculation and application to the input signal, even without access to an undistorted signal, using parameter estimation and symbol lookup processes, potentially aided by machine learning algorithms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If power amplifiers operate non-linearly to amplify signals, then amplification power is improved, but signal distortion in amplitude and phase increases

Engineering Contradiction:
Improveamplification powerVSAvoidsignal distortion
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The pre-distorter applies preliminary anti-action by introducing pre-distortion to the input signal that is the inverse of the expected amplifier distortion. This pre-distortion compensates for the non-linear effects before the signal enters the power amplifier, thereby canceling out the harmful distortion that would otherwise be generated during amplification.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system converts the harmful non-linear distortion characteristic of power amplifiers into a benefit by characterizing the distortion pattern and applying its inverse as pre-distortion. The harmful non-linearity is transformed into a useful compensation mechanism that enables linear amplification output.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Measurement precision

If pre-distortion is applied to compensate for amplifier distortion, then signal accuracy is improved, but system complexity increases

Engineering Contradiction:
Improvesignal accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The pre-distorter design block performs self-service by automatically identifying distortion characteristics from the amplifier output and generating appropriate pre-distortion parameters without requiring external calibration equipment or manual intervention. The system uses the finite set of symbols associated with the output signal to self-correct the distortion.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system applies parameter changes by modifying the pre-distortion parameters based on identified distortion characteristics. The pre-distorter design block updates the pre-distortion parameters dynamically to match the actual amplifier behavior, allowing adaptation to changing operating conditions while maintaining signal accuracy.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If traditional pre-distortion methods are used requiring access to undistorted signals, then pre-distortion accuracy is improved, but applicability to real-world systems deteriorates

Engineering Contradiction:
Improvepre-distortion accuracyVSAvoidsystem applicability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The finite set of symbols acts as an intermediary between the distorted output signal and the pre-distortion calculation process. Instead of requiring direct access to the original undistorted signal, the system uses the known symbol set as a reference to identify distortion characteristics and derive pre-distortion parameters, enabling operation in practical systems where undistorted signals are unavailable.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system inverts the traditional pre-distortion approach by working backward from the distorted output to determine the necessary pre-distortion. Instead of starting with the undistorted signal and predicting distortion, the method starts with the distorted output and the known symbol set to infer the distortion characteristics and calculate the compensating pre-distortion.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP3985867A1Pre-distortion pattern recognition
Publication Date: 2022.04.20 HONEYWELL INTERNATIONAL INC
  • EP3985867A1 patent drawingFigure 1
  • EP3985867A1 patent drawingFigure 2
  • EP3985867A1 patent drawingFigure 3

AI summary

Systems and methods for pre-distortion pattern recognition are provided. In certain embodiments, the system includes an electronic device that provides an output signal, wherein the electronic device applies distortion to the output signal. The system also includes a pre-distorter that provides an input signal to the electronic device, wherein the pre-distorter applies a pre-distortion to the input signal before the electronic device receives the input signal. Further, the system includes a pre-distorter design block that identifies the distortion from an association between the output signal and a finite set of symbols and updates the pre-distortion based on the association.