Antenna Array Spatial Filtering via Digital Beam Steering
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Solution Overview
Problem
Current methods for three-dimensional multiple signal tracking and reconstruction, particularly for applications like search and rescue, surveillance, and seismic monitoring, face challenges in accurately determining the direction and characteristics of quasi-continuous signals without rotating antennas, and in handling multiple simultaneous sources with minimal interference.
Innovation Solution
The system employs signal vector processing to create mathematical models of physical wave fields, using antenna arrays and digital signal processing to steer 'antenna beams' and remove undesired sources, allowing for the determination of signal directions and power spectra without antenna rotation, and enables simultaneous transmission of spectrally competitive signals into resolvable directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If analog beamforming and antenna steering methods are used for direction finding, then the system can track quasi-continuous signals, but the antenna must be rotated or mechanically steered which increases device complexity and reduces reliability
Solution Approach 1:
The patent replaces mechanical antenna rotation with electronic beam steering using digital signal processing. Multiple antenna elements form an array where electronic phase shifters and time delays control the beam direction without any mechanical movement. This substitution of mechanical systems with electronic/digital systems resolves the contradiction by maintaining direction-finding accuracy while eliminating the complexity and reliability issues of rotating mechanisms.
Solution Approach 2:
The patent divides a single large antenna into multiple smaller antenna elements arranged in an array. Each element can be independently controlled with electronic phase shifters and time delay devices. This segmentation allows the system to achieve beam steering through electronic means rather than mechanical rotation, resolving the technical contradiction between measurement precision and device complexity.
2Device complexity
If fixed antenna arrays with digital signal processing are used, then antenna rotation is eliminated, but the system struggles to handle multiple simultaneous sources with minimal interference
Solution Approach 1:
The patent applies adaptive beamforming techniques that create different beam patterns for different spatial locations. Each antenna element contributes to forming direction-specific beams with tailored characteristics. This local quality approach allows the system to simultaneously track multiple sources by directing specific beam patterns toward each source, minimizing interference while maintaining structural simplicity.
Solution Approach 2:
The patent implements adaptive signal processing where beam patterns dynamically adjust based on the spatial distribution of multiple sources. The system continuously optimizes weightings and phase shifts for each antenna element to maintain optimal beam formation for current source configurations, enabling effective handling of multiple simultaneous sources without increasing structural complexity.
3Measurement precision
If second order statistical functions are used for signal processing, then preferred signal directions can be determined, but the processing complexity and computational requirements increase
Solution Approach 1:
The patent pre-calculates and stores steering vectors and beamforming weights for various directions before actual signal processing. These pre-computed parameters are stored in lookup tables or memory structures. During operation, the system simply retrieves and applies these pre-computed values rather than performing complex real-time calculations, thereby maintaining high measurement precision while reducing processing complexity and computational requirements.
Data Source
AI summary
Methods and systems for spatial filtering transmitters and receivers capable of simultaneous communication with one or more receivers and transmitters, respectively, the receivers capable of outputting source directions to humans or devices. The methods and systems use spherical wave field partial wave expansion (PWE) models for transmitted and received fields at antennas and for waves generated by contributing sources. The source PWE models have expansion coefficients expressed as functions of directional coordinates of the sources. For spatial filtering receivers a processor uses the output signals from at least one sensor outputting signals consistent with Nyquist criteria representative of the wave field and the source PWE model to determines directional coordinates of sources (wherein the number of floating point operations are reduced) and outputs the directional coordinates and communications to a reporter configured for reporting information to humans. For spatial filtering transmitters a processor uses known receiver directions and source partial wave expansions to generate signals for transducers producing a composite total wave field conveying communications to the specified receivers. The methods and communications reduce the processing required for transmitting and receiving spatially filtered communications.