Sparse Antenna Array Calibration for High-Resolution Beamforming
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Solution Overview
Problem
Current beamforming techniques in satellite communications have limited resolution and are unable to effectively increase frequency reuse due to the size and rigidity of traditional antenna arrays, which restricts the ability to support a large number of users within a geographic area.
Innovation Solution
A large, sparse antenna array with uneven inter-element spacing is used, combined with beam coefficients determined through geometric interpretation and MIMO techniques, to form small communication beams with precise coverage areas, allowing for increased frequency reuse and user capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional antenna arrays are used with consistent inter-element spacing, then the array structure is rigid and easy to manufacture, but the beamforming resolution is limited and frequency reuse cannot be effectively increased
Solution Approach 1:
The patent applies asymmetry by transitioning from a traditional uniform antenna array to a sparse antenna array with non-uniform inter-element spacing. The antenna elements are strategically positioned at different distances from the reflector, creating an asymmetric geometry that enables higher beamforming resolution and frequency reuse while maintaining manageable structural complexity through mathematical optimization.
2Measurement precision
If the antenna array size is increased to improve beamforming resolution, then the coverage area increases, but the ability to form small communication beams with precise coverage is reduced
Solution Approach 1:
The patent applies segmentation by dividing the antenna array into sparse, non-uniformly spaced elements rather than using a dense uniform grid. This segmentation allows the system to achieve high beamforming resolution for forming small, precise communication beams while the overall array footprint remains manageable, effectively decoupling resolution from coverage area.
3Productivity
If beamforming techniques are used to increase frequency reuse, then spectral efficiency improves, but the traditional antenna array structure cannot support a large number of users within a geographic area
Solution Approach 1:
The patent applies dynamics by implementing a reconfigurable sparse antenna array where elements can be dynamically positioned and adjusted. This dynamic capability allows the system to adaptively form multiple narrow beams simultaneously, enabling frequent time-division duplexing (TDD) and supporting a large number of users within a geographic area, thereby significantly improving frequency reuse and spectral efficiency.
Data Source
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AI summary
A system for communications may include an antenna array, where an inter-element spacing of antennas of the antenna array may be different across the antenna array; antenna managers that are coupled with respective antennas and configured to transmit and receive ranging signals used to measure parameters representative of distances between a respective antenna and the other antennas; a calibration unit that determines positions of the antennas based on the measured parameters and positions of reference antennas; and a communications manager that communicates with a terminal according to beam coefficients determined for the antenna array based on the determined positions of the antennas.