Zero-IF Baseband DC Offset Detection for Radar Distance Accuracy
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Solution Overview
Problem
Zero-IF receivers face challenges in accurately determining and compensating for DC components, which interfere with phase-modulated signals and affect distance determination in radar systems, as existing methods are inefficient and not applicable to all signal types.
Innovation Solution
A device and method for determining the DC component in a zero-IF receiver by analyzing a complex baseband signal to select at least three samples and calculating the intersection of perpendicular bisectors, allowing for effective DC compensation and improved distance determination in radar systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If zero-IF architecture is used to relax filter requirements and eliminate conversion steps, then device complexity is reduced, but a strong DC component is introduced that interferes with the wanted signal
Solution Approach 1:
The patent extracts the DC component from the complex baseband signal by selecting specific samples and calculating the intersection of perpendicular bisectors, effectively separating the harmful DC offset from the wanted signal to enable accurate DC compensation
Solution Approach 2:
The patent introduces an intermediary geometric construction method using perpendicular bisectors as a mediator to indirectly determine the DC component position, avoiding direct measurement of the interfering DC offset while enabling its removal
2Ease of manufacture
If conventional DC estimation methods are used, then implementation is simple for some modulations, but they are not applicable to phase-modulated signals like FM
Solution Approach 1:
The patent creates a universal DC estimation method based on geometric properties of constellation diagrams that works across different modulation types including phase-modulated signals, making the DC compensation applicable to various signal types beyond simple modulations
3Device complexity
If DC component is not compensated, then signal processing is simpler, but distance determination accuracy in radar systems deteriorates
Solution Approach 1:
The patent performs preliminary DC component determination and compensation before phase extraction and distance calculation in radar signal processing, eliminating the interfering DC offset in advance to ensure accurate distance determination without adding complexity to subsequent processing steps
Data Source
AI summary
A device for determining a DC component in a zero-IF radio receiver comprises an input configured to receive a complex baseband signal; and an analyzer configured to analyze the complex baseband signal to determine a DC component in the complex baseband signal by selecting at least three samples of the complex baseband signal and determining the intersection of at least two perpendicular bisectors of at least two straight lines, each straight line running through a different pair of two of said selected samples, said intersection representing the DC component. Further, a corresponding method, a radar device and a radar method are disclosed.