Frequency-Domain I/Q Imbalance Correction for Wideband Transceivers

Solution Overview

Problem

The increasing signal bandwidth and higher center frequencies in 5G wireless communication systems pose a significant challenge for I/Q imbalance correction, as existing time domain methods become prohibitively complex and power-consuming, especially when dealing with wide-bandwidth signals.

Innovation Solution

Implementing I/Q imbalance correction in the frequency domain using a method that modifies input I/Q data based on correction coefficients, where the I/Q imbalance correction circuit generates corrected data by combining the original data with its complex conjugate at a mirror image frequency, reducing complexity and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If time domain I/Q imbalance correction is used, then correction accuracy is maintained, but device complexity and power consumption increase quadratically with signal bandwidth

Engineering Contradiction:

Improvecorrection accuracyVSAvoidcorrection complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transforms the correction operation from time domain to frequency domain, changing the mathematical representation parameters. In frequency domain, the correction involves simple complex multiplication and addition operations on FFT coefficients, whereas time domain requires complex filtering operations that scale quadratically with bandwidth. This parameter transformation maintains correction accuracy while dramatically reducing computational complexity for wideband signals.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the time domain filtering mechanism with a frequency domain algebraic operation mechanism. Instead of using long impulse response filters in time domain that require extensive computational resources, the invention uses direct frequency domain multiplication of the signal spectrum with correction coefficients, substituting a computationally intensive mechanical filtering process with a simpler algebraic operation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If time domain I/Q imbalance correction is used, then correction accuracy is maintained, but power consumption increases quadratically with signal bandwidth

Engineering Contradiction:

Improvecorrection accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent transforms the correction operation from time domain to frequency domain, changing the mathematical representation parameters. In frequency domain, the correction involves simple complex multiplication and addition operations on FFT coefficients, whereas time domain requires complex filtering operations that scale quadratically with bandwidth. This parameter transformation maintains correction accuracy while dramatically reducing computational complexity for wideband signals.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If frequency domain correction is implemented, then device complexity and power consumption are reduced, but correction effectiveness must be maintained across wide bandwidths

Engineering Contradiction:

Improvecorrection complexityVSAvoidcorrection effectiveness

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent moves the correction operation from the time dimension to the frequency dimension by applying FFT transformation. The I/Q imbalance correction is performed in the frequency domain where the relationship between imbalanced components and their image frequencies becomes clearly separated and can be corrected through simple complex arithmetic operations on the spectral coefficients, maintaining effectiveness across wide bandwidths with reduced complexity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent transforms the correction operation from time domain to frequency domain, changing the mathematical representation parameters. In frequency domain, the correction involves simple complex multiplication and addition operations on FFT coefficients, whereas time domain requires complex filtering operations that scale quadratically with bandwidth. This parameter transformation maintains correction accuracy while dramatically reducing computational complexity for wideband signals.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12068904B2Method and apparatus for in-phase and quadrature imbalance correction in a frequency domain

Publication Date: 2024.08.20 INTEL CORP

AI summary

An apparatus and method for in-phase/quadrature (I/Q) imbalance correction in a transceiver. The apparatus includes an I/Q imbalance correction circuit and a correction coefficient generation circuit. The I/Q imbalance correction circuit is configured to modify I/Q data in a frequency domain using correction coefficients to generate corrected I/Q data. The correction coefficient generation circuit is configured to generate the correction coefficients for the I/Q imbalance correction circuit based on the I/Q data and reference data.