PA Distortion Estimation Using Low-Quality Feedback Signals
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Solution Overview
Problem
Current RF transceiver systems face challenges in accurately measuring distortion parameters, particularly in-band and out-of-band distortions, due to limitations in signal processing quality and dynamic range, which restricts the effectiveness of adaptive algorithms in reducing power amplifier current consumption and maintaining linearity within communication standards.
Innovation Solution
A distortion estimation apparatus comprising a feedback element, a nonlinearity determiner, and a distortion simulator, which processes feedback signals with lower quality than the distorted output signals to estimate transmission characteristics and calculate distortion measures, enabling accurate measurement of PA nonlinearity and distortion parameters without requiring high dynamic range receivers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high dynamic range receivers are used to accurately measure distortion parameters, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent creates a digital copy of the feedback signal path and processes it through virtual instrumentation software. Instead of using complex hardware receivers, the system copies the signal flow and uses software-based signal processing to measure distortion parameters, thereby reducing hardware complexity while maintaining measurement precision
Solution Approach 2:
The patent replaces the mechanical/electrical complex receiver hardware system with a software-based processing system. By using virtual instrumentation and digital signal processing algorithms, the system substitutes physical receiver complexity with computational processing, achieving accurate distortion measurement without high dynamic range hardware receivers
2Power
If power amplifier operates at higher power to improve output performance, then power output is improved, but signal distortion increases
Solution Approach 1:
The patent implements a feedback mechanism where distortion parameters are continuously measured and fed back to adjust the power amplifier operation. The system measures distortion at the current operating point and uses this information to optimize the PA's operation, enabling it to operate at higher powers while maintaining acceptable linearity through adaptive control
Solution Approach 2:
The patent makes the power amplifier operation dynamic by continuously monitoring distortion parameters and adapting the operating conditions. Instead of fixed operation, the system dynamically adjusts PA parameters based on real-time distortion measurements, allowing optimal operation across varying power levels and maintaining signal linearity even at high output powers
3Use of energy by moving object
If adaptive algorithms are used to reduce power amplifier current consumption, then energy efficiency is improved, but measurement of linearity becomes more critical and complex
Solution Approach 1:
The patent copies the feedback signal and creates multiple processed versions for different measurement purposes. By digitally copying and processing the signal through different algorithms, the system can extract multiple linearity parameters simultaneously without requiring additional complex measurement hardware, thus simplifying the measurement process while enabling sophisticated adaptive control
Solution Approach 2:
The patent creates a universal measurement system that can perform multiple linearity measurements using a single feedback path. The software-based approach allows the same hardware to measure various distortion parameters (in-band, out-of-band, intermodulation products) by applying different processing algorithms, thereby reducing measurement complexity while providing comprehensive linearity assessment for adaptive algorithms
Data Source
AI summary
A distortion estimation apparatus for estimating distortion includes a feedback element, a nonlinearity determiner, and a distortion simulator. The feedback element provides a feedback signal derived from a distorted output signal of the distorting element. A signal processing quality of the feedback element is lower than an associated signal property of the distorted output signal. The nonlinearity determiner receives the feedback signal and an input signal to the distorting element or a signal derived from the input signal. The nonlinearity determiner determines an estimated transmission characteristic of the distorting element by relating signal properties of the feedback signal and the input signal or the signal derived from the input signal. The distortion simulator estimates the distortion caused by the distorting element based on the input signal or the signal derived from the input signal and the estimated transmission characteristic.