Joint TX/RX IQ Calibration Using High-Order Nonlinear Terms
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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 interdependencies between transmitting and receiving units, leading to IQ imbalance and reduced signal quality.
Innovation Solution
A wireless communication device and method that employs a high-order IQ calibration model to jointly calibrate both the transmitting and receiving units, incorporating higher-order terms to model nonlinear errors and account for interdependencies, using a single calibration process to improve 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 parameters of the calibration model by introducing high-order terms (third-order and higher) to capture nonlinear relationships between IQ components. This transforms the simple linear statistics algorithm into a complex high-order polynomial model that accurately represents the nonlinear behavior of IQ modulators and demodulators in complex communication scenarios.
Solution Approach 2:
The patent adds additional dimensions to the calibration model by incorporating high-order interaction terms between IQ components. Instead of calibrating I and Q components independently with simple statistics, the model considers joint high-order interactions, effectively moving from a low-dimensional to a high-dimensional calibration space that captures complex dependencies.
2Reliability
If separate calibration methods are used for transmitting and receiving units, then each unit can be calibrated independently, but interdependencies between units are not accounted for
Solution Approach 1:
The patent merges the calibration processes of transmitting and receiving units into a single unified calibration framework. By combining both units in one calibration system, the method captures interdependencies between transmitter and receiver, ensuring that calibration compensates for interactions between the two units rather than treating them as independent entities.
Solution Approach 2:
The patent creates a universal calibration model that serves both transmitting and receiving units simultaneously. This multi-functional calibration system can handle both units with a single process, making the calibration procedure universally applicable to both ends of the communication link while accounting for their相互 dependencies.
3Measurement precision
If high-order terms are added to the calibration model, then calibration accuracy improves, but computational complexity increases
Solution Approach 1:
The patent performs preliminary actions by pre-computing and storing high-order calibration coefficients during system initialization or offline processing. This allows the actual time-critical calibration operation to simply involve looking up and applying pre-computed coefficients rather than performing complex real-time calculations, thus maintaining high accuracy while improving processing speed during active communication.
Data Source
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.