Radar Beam Nulling for Multipath Interference Suppression
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Solution Overview
Problem
Radar systems face challenges with multipath interference, leading to false object detection, incorrect target identification, increased radar resource utilization, and degraded signal-to-noise ratio, which can result in improper lethality assessments and resource misallocation.
Innovation Solution
A method and system for reducing multipath interference by determining digital beamforming weights to create a null in the direction of interference, adjusting the null location to avoid targets, and applying these weights during reception to eliminate multipath signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If digital beamforming weights are adjusted to create a null in the direction of multipath interference, then multipath interference is reduced, but the risk of nulling the target signal increases
Solution Approach 1:
The system performs preliminary actions by calculating the distance between the target and multipath interference sources before creating the null. Based on this pre-calculated distance, the system decides whether to create a null at the interference direction or adjust it to avoid the target, thereby preventing target nulling before it occurs
Solution Approach 2:
The system uses feedback by continuously monitoring the distance between target and interference sources, and adjusting the null position based on this feedback. When the distance is less than a threshold, the null position is adjusted away from the target direction, creating a dynamic adaptation mechanism that prevents target signal degradation
2Measurement precision
If the radar system increases processing to maintain track accuracy under multipath interference, then detection precision is maintained, but radar processing time increases
Solution Approach 1:
The system performs preliminary classification of multipath interference based on geometric relationships (distance calculations) before full radar processing. By identifying and handling multipath cases early using simple distance comparisons, the system avoids time-consuming iterative processing for cases that can be resolved through geometric nulling
Solution Approach 2:
The system extracts and handles multipath interference as a separate case from general target processing. By identifying multipath scenarios through distance-based detection and applying specialized nulling techniques, the system removes the computationally intensive interference cancellation processing from the general tracking pipeline, reducing overall processing time
3Reliability
If the radar system uses adaptive beamforming to eliminate multipath interference, then signal-to-noise ratio is improved, but device complexity increases
Solution Approach 1:
The system applies local quality by creating a null only in the specific direction where multipath interference is detected, rather than applying complex adaptive beamforming across all directions. The digital beamforming weights are adjusted locally at the null position to cancel interference, while maintaining simple weighting elsewhere, thereby reducing overall system complexity
Solution Approach 2:
The system changes parameters by adjusting digital beamforming weights based on the calculated distance and direction of multipath interference. Instead of using complex adaptive algorithms, the system modifies beamforming parameters (weights and null positions) based on geometric calculations, simplifying the processing while maintaining effectiveness
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces multipath interference, improving track accuracy, continuity, and radar resource allocation, ensuring accurate target detection and reducing false object identification.
Implementation Method 1
The electromagnetic waves can impinge upon objects which can cause at least a portion of the electromagnetic waves to be reflected back towards the radar system
Implementation Method 2
determining a second set of digital beamforming weights based on the first set of digital beamforming weights to create a null in each of the one or more digital beams in the direction of the multipath interference
Data Source
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AI summary
A radar system and method are provided for reducing multipath interference signals. The multipath interference signals can be reduced by the radar system emitting electromagnetic waves that creates a null in the direction of expected multipath interference signals, such that the multipath interference signals are void (or substantially void) from signals received by the radar system.