IQ Mismatch Correction Function Refinement for Zero-IF Receivers

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Solution Overview

Problem

IQ gain/phase imbalances in zero-IF receivers impair the amplitude and phase relationship between in-phase and quadrature-phase signals, leading to inaccurate signal reception due to mismatches in local oscillator components and analog filters/converters.

Innovation Solution

An IQ mismatch correction function generator is employed to generate initial and enhanced correction functions based on IQ estimates, with error mitigation logic determining errors and a feedback loop refining these functions to improve accuracy, thereby compensating for IQ mismatches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional IQ mismatch correction is used, then the correction process is simple, but the accuracy of signal reception is poor due to IQ gain/phase imbalances

Engineering Contradiction:
Improveaccuracy of signal receptionVSAvoidcomplexity of correction function generator
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The correction function generation is divided into multiple stages: initial correction function generation, error determination, and enhanced correction function generation. This segmentation allows the system to progressively improve accuracy without requiring all complexity at once, resolving the contradiction between measurement precision and device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary error determination by comparing initial correction values with actual IQ estimates before generating the final enhanced correction function. This preliminary action enables the system to identify and correct specific errors, improving signal reception accuracy while maintaining manageable complexity through structured error mitigation.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If iterative refinement of correction functions is performed, then the accuracy of IQ mismatch correction is improved, but the processing time increases

Engineering Contradiction:
Improveaccuracy of IQ mismatch correctionVSAvoidprocessing time for correction
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system implements feedback by determining errors between initial correction function values and actual IQ mismatch estimates, then using this error information to generate enhanced correction functions. This feedback mechanism enables iterative refinement that improves accuracy while controlling processing time through targeted error correction rather than exhaustive optimization.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs partial refinement by focusing error mitigation on specific frequency bins where mismatches occur, rather than uniformly processing all frequency components. This selective approach improves IQ mismatch correction accuracy while reducing overall processing time by concentrating computational resources where most needed.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If correction functions are generated for all frequency bins, then the coverage is complete, but the computational complexity increases

Engineering Contradiction:
Improvecoverage of frequency binsVSAvoidcomputational complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system applies local quality by determining errors and generating enhanced correction functions specifically for frequency bins where IQ mismatches are detected, rather than uniformly processing all frequency bins. This localized approach maintains complete coverage of affected frequencies while reducing computational complexity by avoiding unnecessary processing of bins without mismatches.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS10715376B2Enhanced IQ mismatch correction function generator
Publication Date: 2020.07.14 TEXAS INSTRUMENTS INC
  • US10715376B2 patent drawing
  • US10715376B2 patent drawing
  • US10715376B2 patent drawing

AI summary

An IQ mismatch correction function generator configured to generate an enhanced IQ mismatch correction function to improve the compensation for IQ mismatch, and an IQ signal receiver with the IQ mismatch correction function generator, wherein the enhanced IQ mismatch correction function is determined based on an initial IQ mismatch correction function derived from IQ mismatch estimates corresponding to frequency bins where signals are present and error of the initial IQ mismatch correction function by comparing the values of the initial IQ mismatch correction function with IQ mismatch estimates corresponding to a respective bin of the frequency bins.