RF Transceiver I/Q Calibration via Dual-Tone Test Signals
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Solution Overview
Problem
Existing RF communication systems face challenges in accurately eliminating mirror interference signals caused by mismatches between I and Q mixers, leading to decreased precision in estimating calibration parameters and subsequent interference removal.
Innovation Solution
A signal transceiver system that transmits and receives two test signals with a predefined phase difference, allowing for the calculation of calibration parameters through specific averaging and squaring operations to effectively eliminate mirror interference signals from RF communication signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a test signal is transmitted to estimate calibration parameters for eliminating mirror interference signals, then the mirror interference signal elimination capability is improved, but the accuracy of estimating mismatched parameters decreases due to residual errors generating interference signals in the test signal
Solution Approach 1:
The patent converts the harmful residual error interference signals into useful information by deliberately transmitting two different test signals (single-tone and dual-tone) and measuring their respective interference components. The interference signals generated by residual errors are not simply eliminated but are captured and used to calculate compensation parameters that correct the I/Q mixer mismatches, thereby transforming a harmful factor into a beneficial calibration mechanism
Solution Approach 2:
The patent changes the parameters of the test signal from a single frequency to multiple frequencies (single-tone and dual-tone signals with different frequency relationships). By transmitting test signals with different frequency characteristics and analyzing the resulting interference patterns, the system can separate and measure different components of the residual errors, enabling more accurate estimation of mismatched parameters despite the presence of interference
2Ease of manufacture
If residual errors in the RF transmitter are present, then the system operates with practical hardware limitations, but interference signals contained in the test signal significantly decrease the accuracy of calibration parameter estimation
Solution Approach 1:
The patent performs preliminary measurements by transmitting test signals before actual communication to characterize the residual errors and calculate compensation parameters. By pre-measuring the interference characteristics and computing correction factors in advance, the system prepares the calibration parameters that will be applied during normal operation, thereby eliminating the adverse effects of residual errors on subsequent communication signals
Solution Approach 2:
The patent implements a feedback mechanism where the received test signals are analyzed to estimate calibration parameters, which are then used to adjust the transmitter or receiver settings. The system continuously monitors the effect of calibration and can perform iterative adjustments, using the measured interference signals as feedback to refine the compensation parameters and improve calibration accuracy
Data Source
AI summary
Disclosed is a receiver (200) comprising a signal receiving module (201) configured to receive a first test signal and receive a second test signal after a predefined time period following the completion of the reception of the first test signal, and a calculating module (202) configured to calculate a calibration parameter for calibrating a received RF communication signal, based on the received first test signal and the received second test signal. Correspondingly, a transmitter, a signal transceiver, a signal receiving method, and a signal transmitting method are disclosed.