Joint IQ Calibration Using High-Order Tx/Rx Error Modeling
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Solution Overview
Problem
Current IQ calibration methods in wireless communication systems are inadequate for complex scenarios requiring high calibration accuracy, as they primarily rely on simple signal statistics algorithms that fail to account for the interdependencies between transmitting and receiving units, leading to reduced signal quality and increased errors.
Innovation Solution
A wireless communication device and method that jointly calibrate IQ imbalance in both transmitting and receiving units using a high-order IQ calibration model, incorporating compensation coefficients to account for nonlinear errors and interdependencies, thereby improving calibration accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If simple signal statistics algorithms are used for IQ calibration, then the calibration process is simple and fast, but the calibration accuracy is insufficient for complex scenarios
Solution Approach 1:
The patent changes the mathematical parameters of the calibration model from simple linear relationships to high-order nonlinear terms. The IQ calibration model includes high-order terms such as second-order and third-order nonlinear components that accurately capture the complex amplitude and phase imbalances in transmitting and receiving units, thereby improving calibration accuracy for complex scenarios.
Solution Approach 2:
The patent segments the calibration process into two distinct parts: transmitting unit calibration and receiving unit calibration. Each unit has its own high-order calibration model with separate compensation coefficients. This segmentation allows independent optimization of each unit's calibration accuracy while maintaining overall system performance.
2Reliability
If separate calibrations are performed for transmitting and receiving units, then each unit can be calibrated independently, but the total calibration time and cost increase
Solution Approach 1:
The patent merges the calibration processes of transmitting and receiving units into a unified joint calibration framework. Both units are calibrated simultaneously using a combined high-order model that accounts for their interdependencies. This merging reduces total calibration time and cost while maintaining complete calibration coverage for both units.
Solution Approach 2:
The patent implements a feedback mechanism where the calibration results of one unit inform the calibration of the other unit. The receiving unit's calibration feedback is used to refine the transmitting unit's compensation coefficients, and vice versa. This iterative feedback process ensures both units are accurately calibrated while reducing overall calibration time through coordinated optimization.
Data Source
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AI summary
A wireless communication device and a method for IQ calibration are provided. The device includes a transmitting unit for generating a set of RF transmitting signals based on a set of digital baseband signals, each of the set of RF transmitting signals has IQ components; a receiving unit for generating a set of digital feedback signals based on a set of RF receiving signals obtained from the set of RF transmitting signals; a processing unit for obtaining a first set of compensation coefficients for the transmitting unit and a second set of compensation coefficients for the receiving unit based on the set of digital baseband signals and the set of digital feedback signals with an IQ calibration model, the IQ calibration model includes a first high-order term set about a nonlinear error in the transmitting unit and a second high-order term set bout a nonlinear error in the receiving unit.