Blind Dehopping Signal Characterization via FPGA Pre-Tracking
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Solution Overview
Problem
Current methods for intercepting and characterizing frequency hopping networks face challenges in real-time monitoring, data stream reconstruction, and decoding, particularly in managing multiple channels across the VHF and UHF bands.
Innovation Solution
A method and device that convert signals into digital form, synchronize with frequency jumps, determine central frequencies, apply delays, and use FPGA-based processing to de-interleave and characterize frequency hopping signals, enabling real-time monitoring and data chaining without prior knowledge of frequency laws.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If traditional frequency hopping interception methods are used, then basic signal detection is possible, but real-time monitoring and data stream reconstruction cannot be achieved without knowing the frequency law
Solution Approach 1:
The patent applies preliminary action by performing frequency estimation and tracking before data stream reconstruction. The system pre-processes the frequency-hopped signal to estimate instantaneous frequency, predict future frequencies, and establish the frequency hopping pattern in advance, enabling subsequent blind deinterleaving without requiring prior knowledge of the frequency law
Solution Approach 2:
The patent introduces an intermediary frequency estimation and tracking module that acts as a bridge between the raw frequency-hopped signal and the deinterleaving process. This intermediary component extracts frequency characteristics and generates predictions that facilitate blind deinterleving, allowing data reconstruction without direct knowledge of the frequency hopping sequence
2Adaptability or versatility
If multiple elementary channels are processed in parallel, then coverage of VHF and UHF bands is achieved, but system complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the wideband frequency hopping signal into multiple parallel elementary channels (e.g., 5 channels of 40 MHz each covering the UHF band). Each channel is processed independently through identical processing blocks, allowing scalable architecture that can be adapted to different bandwidth requirements while maintaining manageable complexity through modular design
Solution Approach 2:
The patent implements universality by designing a universal processing block that can handle multiple elementary channels with the same processing algorithm. The frequency estimation, tracking, and deinterleving modules are configured to process any 40 MHz channel identically, enabling the system to cover VHF and UHF bands through parallel configuration rather than requiring different processing paths for different frequency ranges
3Productivity
If frequency tracking algorithms are implemented in FPGA, then real-time processing is achieved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent replaces traditional software-based frequency tracking algorithms with hardware-implemented algorithms in FPGA. The frequency estimation, tracking, and deinterleving operations are implemented as parallel hardware circuits that process signals in real-time, substituting sequential software execution with concurrent hardware processing to achieve the required processing speed
Solution Approach 2:
The patent applies preliminary action by pre-configuring the FPGA with the frequency estimation and tracking algorithms during manufacturing. The FPGA is programmed with the specific frequency hopping prediction algorithms and deinterleving patterns, allowing the hardware to perform real-time processing without requiring complex runtime configuration or software loading, thereby simplifying deployment while maintaining high processing speed
Data Source
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AI summary
The invention concerns a method for real-time characterizing of frequency hopping networks which consists in converting the signal to be characterized into a digital signal, determining the frequency characteristics of the signal, including at least the following steps: searching for a frequency hop to be synchronized on the start of transmission; monitoring the frequency and searching for the central frequency Fc of the desired transmission channel; applying a delay on the samples digitized during the monitoring phase; determining the samples corresponding to the signal threshold from the delayed sample and the discovered central frequency.