I/Q Imbalance Compensation in Wireless Transceivers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication systems face signal imbalance issues due to I/Q imbalance, which causes interference between in-phase and quadrature portions of signals, leading to noise generation and orthogonality loss between these signal components.
Innovation Solution
The method involves using single-tone signals to determine multiplier coefficients and applying a frequency-domain least mean square algorithm to update filter coefficients in both transmitters and receivers, thereby reducing I/Q imbalance by compensating for phase mismatches and frequency-related issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If local oscillator signals are mixed into multipliers to enable signal modulation, then signal transmission functionality is achieved, but I/Q imbalance occurs causing interference between quadrature and in-phase portions
Solution Approach 1:
The patent implements feedback mechanisms where the receiver estimates I/Q imbalance parameters from received signals and sends correction information back to the transmitter. The transmitter then adjusts its local oscillator signals and multiplier coefficients accordingly, creating a closed-loop system that continuously compensates for I/Q imbalance without requiring perfect hardware matching.
Solution Approach 2:
The patent dynamically changes operational parameters including local oscillator frequencies, multiplier coefficients, and filter characteristics to compensate for I/Q imbalance. By adjusting these parameters in real-time based on feedback information, the system maintains signal orthogonality while using standard hardware components.
2Reliability
If single-tone signals are used to determine multiplier coefficients, then I/Q imbalance compensation is achieved, but system complexity increases due to additional signal processing steps
Solution Approach 1:
The patent performs preliminary actions by using single-tone test signals to pre-determine optimal multiplier coefficients and filter parameters before actual communication begins. This calibration process occurs during system initialization or periodic maintenance, allowing the main communication to proceed with simplified processing using the pre-computed parameters.
Solution Approach 2:
The patent creates simplified copies of the complex signal processing task by using single-tone test signals that replicate the essential I/Q imbalance characteristics without requiring full multi-tone signal analysis. This allows the system to determine compensation parameters through easier, faster single-tone measurements rather than complex multi-tone processing.
3Manufacturing precision
If frequency-domain least mean square algorithm is applied to update filter coefficients, then signal orthogonality is maintained, but processing time increases
Solution Approach 1:
The patent applies periodic action by updating filter coefficients using the frequency-domain least mean square algorithm at specific intervals rather than continuously. The system performs these computationally intensive updates during low-activity periods such as signal initialization, periodic calibration cycles, or when channel conditions remain stable, minimizing impact on real-time communication performance.
Data Source
AI summary
Multiplier coefficients are updated according to minimal power value of mixed signals in a wireless communication system. While using updated multiplier parameters, signal imbalance caused by a local oscillator or mismatch between analog elements of the wireless communication system can be reduced, so that the wireless communication system can be immune from noises.