Steered Auxiliary Beam Cancellation for Digital Phased Array Interference
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Solution Overview
Problem
Conventional digital phased arrays face challenges in accurately preserving signals from a target while minimizing interference, particularly due to signal loss associated with existing interference cancellation methods like SLC and LCMV, which are computationally expensive and inefficient for wideband signals and large arrays.
Innovation Solution
The steered auxiliary beam canceller (SABC) algorithm is employed, which configures signal processing circuitry to improve interference cancellation performance by steering a beam towards interference signals, reducing signal loss and computational burden compared to LCMV, while maintaining simplicity similar to SLC.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If SLC (Side-Lobe Canceller) is used for interference cancellation, then device complexity is reduced and ease of operation is improved, but signal loss increases and interference cancellation performance deteriorates
Solution Approach 1:
The patent introduces an auxiliary beam as an intermediary component that captures interference signals from specific directions. This auxiliary beam acts as a mediator between the main beam and the cancellation process, allowing interference to be removed without directly affecting the main beam's signal of interest, thereby reducing signal loss while maintaining operational simplicity
Solution Approach 2:
The patent segments the beamforming function into a main beam for signal reception and a separate auxiliary beam for interference capture. This segmentation allows independent optimization of each beam's function, enabling the auxiliary beam to be specifically designed for interference cancellation while the main beam maintains its signal integrity
2Loss of energy
If LCMV (Linearly Constrained Minimum Variance) beamformer is used for interference cancellation, then signal loss is minimized and interference cancellation performance is improved, but computational cost increases and device complexity increases
Solution Approach 1:
The patent extracts the interference cancellation function from the complex LCMV optimization framework and implements it through a simpler auxiliary beam subtraction approach. By taking out only the essential interference removal capability and implementing it through dedicated auxiliary beams rather than full adaptive optimization, the system achieves effective cancellation with reduced computational complexity
Solution Approach 2:
The patent uses computationally inexpensive auxiliary beam calculations instead of expensive real-time LCMV optimization. The auxiliary beams are calculated using simpler methods that require less computational resources, making the system more practical for implementation while still achieving effective interference cancellation
3Reliability
If LCMV (Linearly Constrained Minimum Variance) beamformer is used for interference cancellation, then interference cancellation performance is improved, but computational cost increases and productivity decreases
Solution Approach 1:
The auxiliary beam serves as a mediator that pre-processes interference signals before they affect the main beam output. This intermediary approach allows interference to be cancelled with simpler computations rather than requiring the full computational power of LCMV real-time optimization
Solution Approach 2:
The patent performs preliminary calculation of auxiliary beam weights offline or in advance, rather than computing them in real-time during signal processing. This preliminary action separates the computationally intensive weight calculation from the real-time signal processing, improving computational efficiency while maintaining cancellation performance
Data Source
AI summary
A digital phased array may include a plurality of antenna elements forming a main array of the digital phased array, a plurality of mixers configured to down-convert data received at respective ones of the antenna elements, a plurality of analog-to-digital converters configured to digitize data provided by corresponding ones of the mixers, and a digital signal processor. The digital signal processor may be configured to receive digitized data including at least one interference signal and at least one desired signal, determine an angle of arrival of the at least one interference signal, steer a beam of the main array toward the at least one interference signal based on the determined angle of arrival, and perform interference cancellation relative to the at least one interference signal.