Antenna Array Null Beamforming With Non-Linear Interference Filtering
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Solution Overview
Problem
Antenna arrays face challenges in accurately recovering weak desired signals in noisy environments with multiple interfering signals, as traditional linear spatial filtering methods fail to separate and suppress interference without degrading signal quality.
Innovation Solution
An antenna array system with an interferer-nulling beam forming network (IN-BFN) and non-linear filters that generate null signals to suppress interference, followed by non-linear filtering to remove interference components and recover desired signals, even when they overlap in time and frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional linear spatial filtering methods are used to suppress interfering signals, then interference attenuation is achieved, but signal quality of the desired signal deteriorates
Solution Approach 1:
The patent divides the interference suppression task into multiple segments by using N different nulling beamforming networks, each generating null signals that suppress different sets of (N-1) interfering signals. This segmentation allows each filter to focus on removing specific interference components while preserving the desired signal, thereby achieving interference attenuation without significant signal quality degradation.
Solution Approach 2:
The patent transitions from traditional linear spatial filtering to a multi-dimensional approach by employing non-linear filtering operations in addition to beamforming. The non-linear filters operate in the signal processing domain to remove remaining interference components that linear methods cannot eliminate, providing an additional dimension of interference suppression that preserves desired signal integrity.
2Object-affected harmful factors
If conventional excision algorithms are used to remove interfering signals, then interference removal is achieved, but signal quality and signal to noise ratio deteriorate unsatisfactorily
Solution Approach 1:
The patent applies preliminary action by using nulling beamforming networks to pre-suppress interfering signals before they reach the non-linear filters. This preliminary suppression reduces the interference burden on subsequent processing stages, allowing the non-linear filters to focus on removing only the remaining interference components while preserving the desired signal with minimal noise introduction.
3Object-affected harmful factors
If multiple nulling beamforming networks are used to suppress interfering signals, then interference attenuation improves, but device complexity increases
Solution Approach 1:
The patent achieves universality by designing the system to handle N interfering signals using N nulling beamforming networks, where each network can suppress different sets of (N-1) interferers. This multi-functional design allows the same basic architecture to adapt to different interference scenarios and configurations, providing flexible interference suppression without requiring entirely different system designs for each case.
Data Source
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AI summary
Disclosed is an antenna array system including an antenna array of N≥2 antenna elements that output N antenna signals; an interferer-nulling beam forming network (IN-BFN) coupled to the antenna array, N non-linear filters coupled to the IN-BFN, and a desired signal BFN. The IN-BFN may include N "null BFNs" to generate N null signals, each null BFN applying a respective nulling beam weight set to the N antenna signals to generate a respective one of the N null signals. Each respective nulling beam weight set corresponds to a different respective set of (N-1) independent nulls. Each of the N non-linear filters may filter a respective one of the N null signals to provide a respective one of N filtered signals. The desired signal BFN may apply a desired signal beam weight set to the N filtered signals to generate an output signal.