MIMO Radar Clutter Suppression via Diagonal Load Windowing
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Solution Overview
Problem
Conventional MIMO radar devices struggle to reduce both direct propagation clutters and multipath clutters in reception signals, as existing methods do not effectively consider multipath clutters.
Innovation Solution
A MIMO radar device with N transmission antennas and M reception antennas, utilizing matched filter banks, a correlation matrix calculating unit, a diagonal load processing unit, a window function calculating unit, and a beam forming unit to generate and apply a window function that suppresses unnecessary signals based on their correlation matrices, thereby reducing direct and multipath clutters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional MIMO beam forming is used, then transmission and reception can be performed, but direct propagation clutters and multipath clutters cannot be effectively reduced
Solution Approach 1:
The patent segments the clutter suppression task into two distinct parts: first calculating a correlation matrix for direct propagation clutters using transmission and reception beam patterns, then separately calculating a correlation matrix for multipath clutters using reflected beam patterns. This segmentation allows each type of clutter to be suppressed independently through separate window functions, resolving the contradiction by addressing both clutter types systematically rather than treating them as a single undifferentiated problem.
Solution Approach 2:
The patent extends the conventional single-dimension beam forming approach by introducing a second dimension for multipath propagation. While conventional methods only consider direct transmission paths, this patent adds the dimension of reflected paths by calculating separate beam patterns for reflections from ground and other surfaces. This dimensional expansion enables simultaneous suppression of both direct and multipath clutters, improving signal quality without sacrificing the ability to perform transmission and reception.
2Object-affected harmful factors
If window function is applied to reduce side lobes, then direct propagation clutters are reduced, but multipath clutters are not considered
Solution Approach 1:
The patent creates a universal clutter suppression framework that handles multiple clutter types through a unified two-stage process. The first stage addresses direct propagation clutters using conventional window functions, while the second stage extends this capability to multipath clutters through additional correlation matrix calculations and window function applications. This multi-functional approach allows the same basic suppression mechanism to work for both direct and reflected clutters, enhancing adaptability without requiring fundamentally different methods for each clutter type.
Solution Approach 2:
The patent applies preliminary action by first calculating and applying the window function for direct propagation clutters, then subsequently calculating and applying a separate window function for multipath clutters. This sequential preliminary action ensures that each clutter type is addressed in a systematic order, with the first suppression operation preparing the signal for the second. This approach expands clutter type coverage while maintaining the effectiveness of direct clutter reduction achieved by conventional methods.
Data Source
Figure 1
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Figure 3A~3B
AI summary
A correlation matrix calculating unit (6) calculates an unnecessary signal correlation matrix. A diagonal load processing unit (7) performs diagonal load processing on the unnecessary signal correlation matrix. A window function calculating unit (8) calculates a window function for obtaining a side lobe characteristic that reduces unnecessary signals on the basis of an unnecessary signal correlation matrix R after the diagonal load processing. A window function applying unit (9) applies the window function to a reception signal vector. A beam forming unit (10) forms a MIMO beam on the basis of the reception signal vector to which the window function is applied and a beam directivity angle.