Frequency-Domain I/Q Imbalance Correction in Wideband Transceivers
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Solution Overview
Problem
In-phase (I) and quadrature (Q) imbalance in transceivers becomes increasingly complex and costly to correct as signal bandwidth increases, especially in 5G wireless communication systems, where traditional time-domain correction methods are not feasible due to high bandwidth and power consumption issues.
Innovation Solution
Implementing I/Q imbalance correction in the frequency domain using a method that modifies I/Q data with correction coefficients generated based on input data and its complex conjugate at a mirror image frequency, allowing for efficient amplitude and phase mismatch correction in a frequency domain framework.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional time-domain correction methods are used for I/Q imbalance, then correction can be applied, but complexity and power consumption increase significantly with signal bandwidth
Solution Approach 1:
The patent transforms the correction operation from time domain to frequency domain by applying FFT to convert time-domain signals into frequency-domain representations. This parameter change in the operational domain allows the correction algorithm to process wideband signals with constant complexity regardless of bandwidth, as the frequency-domain operations scale linearly rather than quadratically with bandwidth increase.
Solution Approach 2:
The patent replaces the traditional time-domain filtering and processing mechanisms with frequency-domain convolution and multiplication operations. By substituting time-domain mechanical processing with frequency-domain mathematical operations, the system achieves O(N log N) complexity through FFT-based approaches instead of O(N²) time-domain convolution, significantly reducing computational burden for wideband signals.
2Reliability
If traditional time-domain correction methods are used for I/Q imbalance, then correction can be applied, but power consumption increases with signal bandwidth
Solution Approach 1:
The patent changes the operational parameter from time-domain processing to frequency-domain processing, which fundamentally alters the computational complexity scaling. Frequency-domain operations using FFT reduce the number of required computations from quadratic to near-linear scaling with bandwidth, directly reducing power consumption in energy-constrained wireless communication systems handling wideband signals.
3Measurement precision
If I/Q imbalance correction is implemented, then signal quality improves, but system complexity increases quadratically with signal bandwidth
Solution Approach 1:
The patent applies a domain transformation parameter change from time to frequency, which alters the complexity scaling behavior. In the frequency domain, the correction operations can be performed independently on each frequency bin, allowing parallel processing and reducing overall system complexity from quadratic to linear or near-linear scaling with bandwidth, while maintaining signal quality through precise complex coefficient multiplication.
Data Source
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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.