RF Calibration for Multi-Antenna Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-antenna mobile communication systems face increased hardware complexity and reduced flexibility due to the need for baseband calculations and additional RF components for RF path calibration, which complicates error detection and calibration.
Innovation Solution
An RF calibration method that generates a transmission reference signal with a 180-degree phase difference to minimize power values on the RF transmission path, and uses a leaked IF signal to calibrate the reception path, eliminating the need for baseband calculations and additional RF converters by utilizing an RF self-loop for phase and gain error correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional baseband calculations and additional RF converters are used for RF path calibration, then phase and gain error detection accuracy is improved, but hardware complexity increases
Solution Approach 1:
The RF calibration apparatus uses the RF transmission path itself to perform calibration by generating a reference signal and comparing it with the transmitted signal. The system self-calibrates without requiring external baseband calculations or additional RF converters, eliminating the need for complex calibration hardware while maintaining accurate phase and gain error detection.
Solution Approach 2:
The invention extracts the calibration function from the baseband processing domain and relocates it to the RF domain. By performing calibration operations at the RF level using the transmission path itself, the system eliminates the need for additional baseband calculation resources and RF converter components, thereby reducing hardware complexity while preserving measurement precision.
2Measurement precision
If additional RF components and baseband calculations are added for calibration, then calibration accuracy is improved, but system flexibility is reduced
Solution Approach 1:
The RF transmission path serves multiple functions: it transmits data signals and simultaneously serves as the calibration reference. The same hardware components used for normal transmission operations are utilized for calibration purposes, eliminating the need for dedicated calibration-only components and maintaining full system flexibility for various communication tasks.
Solution Approach 2:
The calibration function is merged with the existing RF transmission path and signal processing components. By combining calibration operations with normal transmission operations within the same hardware framework, the system achieves accurate calibration without adding separate calibration subsystems that would reduce flexibility.
3Measurement precision
If baseband calculations are used for RF path calibration, then error detection capability is improved, but calculation load increases
Solution Approach 1:
The invention replaces complex baseband mathematical calculations with simpler RF-domain signal processing operations. By performing calibration measurements at the RF level using power detectors and signal comparators rather than extensive baseband computations, the system maintains accurate error detection while significantly reducing the calculation burden on baseband processing units.
Data Source
AI summary
There is provided to an RF calibration apparatus and method for a multi-antenna mobile communication system, which calibrates a phase error and gain error of an RF path by calculating the minimum value of a sum of an initialized reference signal and a comparison signal by a simple operation and controlling the phase value of a phase converter and the gain of a variable amplifier on the RF path, in calibrating the RF path of a multi-antenna mobile communication system of a TDD (Time Division Duplexing) type or FDD (Frequency Division Duplexing) type.