Radio Receiver IQ Correction for Gain and Phase Mismatch
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Solution Overview
Problem
Conventional techniques for setting operational parameters in radios are inadequate to achieve adequate signal-to-noise ratio (SNR) in complex modulation schemes, particularly when IQ errors cause poor signal-to-noise ratios and are exacerbated by temperature, gain, and frequency band mismatches.
Innovation Solution
A method that uses real-time communication signals to measure and correct phase and gain errors in radios by iteratively testing symmetry values and applying correction values to the I and Q signals, thereby reducing amplitude and phase errors through matrix multiplication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional techniques set operational parameters at manufacture or power up, then device complexity is reduced, but signal-to-noise ratio becomes inadequate in complex modulation schemes
Solution Approach 1:
The patent implements dynamic adjustment of operational parameters (gain and phase values) during radio operation based on measured IQ errors. The processor continuously monitors IQ signal symmetry and adjusts parameters in real-time, transitioning from static factory settings to dynamic adaptive control, thereby maintaining adequate SNR in complex modulation schemes.
Solution Approach 2:
The patent employs feedback by measuring IQ signal symmetry and using the measured values to adjust operational parameters. The processor calculates symmetry metrics from received signals and uses this feedback to iteratively optimize gain and phase correction values, creating a closed-loop system that maintains optimal performance.
2Productivity
If modulation schemes use larger numbers of constellation symbols, then data transmission capacity increases, but radio tolerance to IQ errors decreases
Solution Approach 1:
The patent applies preliminary correction by pre-calculating and applying gain and phase compensation values before IQ errors can degrade signal quality. The system proactively measures symmetry and adjusts parameters to counteract expected IQ imbalances, preventing error accumulation in high-order modulation schemes.
Solution Approach 2:
The patent changes operational parameters (gain and phase values) based on measured IQ errors to maintain signal integrity. By dynamically adjusting these parameters according to symmetry measurements, the system adapts to different modulation complexities and maintains adequate error tolerance regardless of constellation size.
3Adaptability or versatility
If temperature, gain, and frequency band mismatches occur, then environmental adaptability is improved, but IQ error magnitude increases
Solution Approach 1:
The patent implements self-service by enabling the radio to automatically measure its own IQ symmetry and adjust its operational parameters without external intervention. The processor monitors symmetry metrics and autonomously corrects gain and phase mismatches, allowing the system to self-adapt to temperature, gain, and frequency variations.
Solution Approach 2:
The patent performs preliminary measurements of IQ symmetry under various operating conditions and establishes correction values before significant degradation occurs. By proactively measuring and correcting parameters in response to environmental changes, the system maintains precision despite adaptability requirements.
Data Source
AI summary
In a radio receiver having first and second mixers that mix a received communication signal to produce quadrature I and Q signals, measuring an output value of the I and Q signals. At a programmed processor: evaluating symmetry in the I and Q signals by calculating a symmetry test value; iteratively testing gain and phase shift correction values by applying the gain and phase shift correction values to the I and Q signals to identify a pair of gain and phase shift correction values that produces an improved symmetry test value; selecting the pair of gain and phase shift correction values; and applying the selected pair of gain and phase shift correction values to the I and Q signals from the first and second mixers. This abstract is not to be considered limiting.