Resilient HF Frequency Selection Against Active Interference
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Solution Overview
Problem
HF waveforms are vulnerable to active and unintentional interference, leading to communication denial in long-range communication systems.
Innovation Solution
A system and method that iteratively computes interferer link budgets and selects frequencies to overcome interference, utilizing a software-defined radio and waveform protocol stack to maintain communication links in the presence of interferers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If HF waveforms are used for long-range communication, then communication range is extended, but vulnerability to interference increases
Solution Approach 1:
The system dynamically changes frequency parameters to avoid interference. The frequency selection algorithm iteratively computes link budgets for multiple frequencies and selects the optimal frequency that minimizes interference impact while maintaining communication range.
Solution Approach 2:
The system uses feedback from link budget computations to adapt frequency selection. By continuously evaluating signal-to-interference ratios and propagation conditions, the system adjusts frequency choices to maintain resilient communication despite interference.
2Reliability
If frequency selection algorithm is implemented to overcome interference, then communication resilience is improved, but computational complexity increases
Solution Approach 1:
The system performs preliminary link budget computations for multiple candidate frequencies before actual communication. By pre-evaluating propagation conditions and interference levels using HF propagation models, the system identifies optimal frequencies in advance, reducing real-time computational burden.
Solution Approach 2:
The frequency selection process is segmented into discrete steps: computing link budgets for individual frequencies, evaluating propagation conditions, comparing signal-to-interference ratios, and selecting the optimal frequency. This segmentation makes the complex algorithm more manageable and implementable.
Data Source
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AI summary
Techniques for selecting frequencies of operation are described. HF signals may land at the receiver node with power levels dependent upon the transmit frequency. The frequency with the highest power level at the receiver node may be selected when the receiver node is not subject to interfering. The receiver node may be unable to receive a desired signal if an interfering signal has a signal level which is higher than the desired signal. The transmitter node may select a frequency which has a receiver signal level which is higher than the interfering signal for the selected frequency. The receiver node may then receive the transmit signal at the selected frequency even when subject to interfering from the interferer node.