Adaptive Interference Cancellation Beamforming for Satellite Links
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Solution Overview
Problem
Conventional beamforming systems, such as Linearly Constrained Minimum Variance (LCMV), struggle with large satellite beams as they require many constraint points, consuming degrees of freedom and leaving limited room for effective interference nulling, and are not adaptable to time-variant interference conditions.
Innovation Solution
The implementation of adaptive interference cancellation (AIC) beamforming using nonlinear least squares (NLS) criterion, which estimates interference locations and strengths, and generates nulls while maintaining beam shape, allowing for both small and large satellite beams and adaptive interference cancellation in both forward and reverse links.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If conventional beamforming systems (LCMV) are used with large satellite beams, then beam coverage area is increased, but the number of constraint points required increases, consuming degrees of freedom and reducing interference nulling capability
Solution Approach 1:
The system transitions from static constraint-point-based beamforming to dynamic interference source estimation. By continuously estimating interference locations and strengths from received signal samples, the system adapts beam weights in real-time without requiring fixed constraint points, enabling large beam coverage while maintaining interference rejection capability
Solution Approach 2:
The approach changes the fundamental parameters from spatial constraint point coordinates to interference source characteristics (location and strength). This parameter transformation allows the system to handle large beam areas by estimating interference properties from signal samples rather than relying on numerous pre-defined constraint points
2Stability of the object's composition
If conventional beamforming systems (LCMV) are used, then beam shape is maintained, but adaptability to time-variant interference conditions is reduced
Solution Approach 1:
The system implements feedback by continuously estimating interference characteristics from received signal samples and using these estimates to update beam weights. This closed-loop approach allows the beamformer to adapt to time-variant interference while maintaining beam shape stability through iterative optimization
Solution Approach 2:
The system performs preliminary estimation of interference locations and strengths from received signal samples before finalizing beam weights. This preliminary action enables the system to prepare adaptive interference cancellation strategies in advance, improving responsiveness to time-variant interference conditions
3Reliability
If adaptive interference cancellation (AIC) beamforming is implemented, then interference cancellation effectiveness is improved, but computational complexity increases
Solution Approach 1:
The system uses received signal samples to automatically estimate interference characteristics and generate appropriate beam weights without external intervention. This self-service approach leverages the actual received signals to drive the interference cancellation process, improving effectiveness while keeping computational requirements manageable through efficient signal processing algorithms
Data Source
AI summary
Methods of operating a transceiver including an antenna having a plurality of antenna feed elements are disclosed. The methods include receiving a plurality of samples of a receive signal from the plurality of antenna feed elements, estimating locations of a plurality of signal sources from the plurality of receive signal samples, identifying a plurality of interference sources from among the plurality of signal sources, generating a plurality of antenna feed element weights wM in response to the locations of the interference sources, forming an antenna beam from the antenna to the geographic region using the antenna feed element weights wM, and communicating information over the antenna beam. Related transceivers, satellite gateways and satellites are also disclosed.