Radio Jamming Cancellation Using Spatially Diverse Antennas
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Solution Overview
Problem
Wireless communications systems, particularly in military applications, are vulnerable to interference and jamming, which degrade communication quality and reliability, and existing technologies struggle to effectively mitigate such interference without prior knowledge of the jamming signal.
Innovation Solution
The described techniques utilize spatially diverse antennas to decorrelate jamming signals by processing signals from multiple antennas, applying a weighting factor to subtract the jamming signal, and demodulating the residual signal to extract the desired signal, employing blind adaptive cancellation algorithms and adaptive filters to dynamically track and remove interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional interference cancellation methods are used, then some interference mitigation is achieved, but they require prior knowledge of the jamming signal which is not available in hostile environments
Solution Approach 1:
The system uses itself to generate the reference signal for cancellation by exploiting the correlation between signals received at spatially diverse antennas. The first antenna receives both desired signal and jamming, while the second antenna receives primarily jamming due to spatial filtering. The system processes its own received signals to create the cancellation reference, eliminating the need for external knowledge of the jamming signal characteristics.
Solution Approach 2:
The patent introduces an intermediary processing mechanism that uses the first received signal as a reference to cancel jamming from the second received signal. This intermediary approach allows the system to bridge the gap between having spatially separated antenna signals and achieving effective jamming cancellation without direct knowledge of the jamming waveform.
2Object-affected harmful factors
If spatially diverse antennas are used to decorrelate jamming signals, then jamming cancellation capability is improved, but system complexity increases
Solution Approach 1:
The system segments the jamming cancellation process into distinct functional blocks: a first received signal input, a second received signal input, a jamming canceller that processes both signals, and an output that produces the canceled signal. This segmentation allows each component to perform a specific function, making the overall complex task of jamming rejection more manageable and implementable.
Solution Approach 2:
Instead of trying to directly filter or identify the jamming signal from the received mixture, the system inverts the approach by using the jamming-containing first signal as a reference to subtract the jamming component from the second signal. This indirect approach simplifies the processing by working with available correlated signals rather than attempting direct jamming detection.
3Reliability
If blind adaptive cancellation algorithms are employed to remove jamming without prior knowledge, then effectiveness against unknown interference is improved, but computational requirements increase
Solution Approach 1:
The system applies partial action by using only the necessary correlation processing between two specific antenna signals rather than performing comprehensive spectral analysis or adaptive filtering across the entire signal bandwidth. This selective approach achieves effective jamming cancellation while minimizing computational energy consumption by focusing only on the essential correlation operation.
Data Source
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AI summary
Methods, systems, and devices for reducing the impact of a jamming signal on wireless communications are described. Generally, the described techniques provide for receiving a first signal at a first antenna and receiving a second signal at a second antenna. An anti-jamming manager may process the first signal and the second signal to obtain a residual signal. The processing may include determining a weighting factor based at least in part on a correlation between the first signal and the second signal, applying the weighting factor to the first signal to create a weighted first signal, and subtracting the weighted first signal from the second signal to obtain the residual signal. A demodulator may demodulate the residual signal to obtain symbol information. A decoder may decode the symbol information to obtain data. The techniques may be used to recover a desired signal portion from a jammed signal.