RF Signal Path Equalization Using Magnitude-Only Distortion Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems require expensive or burdensome hardware for full duplex sampling of RF signal paths to compensate for both amplitude and phase distortions, which is necessary for accurate error vector magnitude measurement and correction.
Innovation Solution
A wireless communications device with a digital-to-analog converter, analog-to-digital converter, and a magnitude detector that determines amplitude and phase distortions, generating an equalization filter for pre-distortion of the transmit signal path, allowing for compensation without the need for expensive Vector Signal Analyzers or full duplex sampling circuitry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If full duplex sampling circuitry is used to compensate for both amplitude and phase distortions, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts only the magnitude information from the RF signal path using a magnitude detector, rather than implementing full complex sampling. By taking out only the necessary magnitude component and deriving phase information mathematically from magnitude measurements at different frequencies, the system achieves distortion compensation without requiring complex full duplex sampling circuitry for I/Q components
Solution Approach 2:
The patent replaces the mechanical/hardware-based full duplex sampling system with a computational approach. Instead of using separate hardware paths for sampling both amplitude and phase directly, the system uses magnitude measurements combined with mathematical processing (Fourier transforms and phase extraction algorithms) to achieve the same distortion compensation function
2Measurement precision
If a Vector Signal Analyzer is used for sampling the transmit signal path, then measurement precision is improved, but cost increases
Solution Approach 1:
The patent replaces expensive Vector Signal Analyzer hardware with a cost-effective integrated magnitude detector and signal processing system. The solution uses standard RF components and computational methods that are significantly cheaper than external VSA equipment, making the system economically viable for commercial wireless devices
Solution Approach 2:
The patent introduces a magnitude detector as an intermediary component that bridges the gap between simple amplitude measurement and complex signal analysis. This intermediary device provides the necessary measurement data for distortion compensation without requiring the full functionality and cost of a Vector Signal Analyzer
Data Source
AI summary
The wireless communications device has a transmit signal path including a digital-to-analog converter and associated circuitry, a receive signal path including an analog-to-digital converter, and a magnitude detector sampling the transmit signal path and providing output to a signal controller. The signal controller is configured to determine amplitude distortion and determine phase distortion based upon information from the magnitude detector, and generate an equalization filter (e.g. during power-up of the wireless communication device), based upon the determined amplitude distortion and phase distortion, for pre-distortion of regular traffic output through the transmit signal path. The approach provides compensation for both amplitude and phase based upon the sampling of an output of a magnitude detector in Radio Frequency (RF) signal paths.