Power Amplifier Predistortion Using Operation Status Signals

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Solution Overview

Problem

Existing distortion compensation devices struggle to effectively compensate for distortion in transmission signals after power amplification, especially when the operation status of the power amplifier changes.

Innovation Solution

A distortion compensation device that includes processing circuitry to acquire an amplification target signal and an operation status signal, and uses a neural network learning model to estimate a predistortion signal for compensating distortion, even when the operation status of the power amplifier changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a learning model is trained to compensate distortion in transmission signals after power amplification, then distortion compensation accuracy is improved under fixed operation conditions, but the system fails to adapt when the operation status of the power amplifier changes

Engineering Contradiction:
Improvedistortion compensation accuracyVSAvoidadaptability to operation status changes
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic adaptation by continuously monitoring operation status signals (temperature, frequency, bias voltage) and updating the learning model's weight coefficients in real-time. This transforms the static predistortion system into a dynamic one that automatically adjusts to changing power amplifier conditions, resolving the contradiction between achieving high compensation accuracy and adapting to operation status changes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameters of the learning model (weight coefficients) based on detected operation status variations. By modifying these parameters in response to temperature, frequency, or bias voltage changes, the system maintains accurate distortion compensation across different operating conditions, simultaneously achieving both precision and adaptability.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the learning model is trained with fixed operation status data, then training speed is improved, but the predistortion signal becomes inaccurate when operation status changes

Engineering Contradiction:
Improvetraining speedVSAvoidpredistortion signal accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The system performs preliminary training with fixed operation status data to establish initial weight coefficients quickly. This preliminary action provides a good starting point that can be rapidly refined through online adaptation when operation status changes occur, balancing training speed with ongoing accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms where the actual distortion compensation performance is monitored and used to continuously adjust the learning model's weight coefficients. This feedback loop ensures that while initial training can be fast, the system continuously improves and maintains accuracy as operation status changes, resolving the contradiction between training speed and signal accuracy.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS20250183855A1Distortion compensation device, distortion compensation method, and transmission device
Publication Date: 2025.06.05 MITSUBISHI ELECTRIC CORP
  • US20250183855A1 patent drawing
  • US20250183855A1 patent drawing
  • US20250183855A1 patent drawing

AI summary

A distortion compensation device includes: an amplification target signal acquiring unit that acquires an amplification target signal to which power amplification by a power amplifier is performed; and an operation status signal acquiring unit that acquires an operation status signal indicating an operation status of the power amplifier. In addition, the distortion compensation device includes a distortion compensation unit that estimates a signal in which distortion is added to the amplification target signal acquired by the amplification target signal acquiring unit as a predistortion signal for compensating distortion generated in the amplification target signal after power amplification by the power amplifier on the basis of the amplification target signal acquired by the amplification target signal acquiring unit and the operation status signal acquired by the operation status signal acquiring unit, and outputs the predistortion signal to the power amplifier.