Digital Receiver Signal Detection via Inter-Correlation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Digital receivers face challenges in detecting signals with long pulse duration and low peak power due to insufficient signal-to-noise ratio and frequency ambiguity, especially in broadband applications with multiple sub-samplings.
Innovation Solution
A method for detecting signals in frequency-ambiguous digital receivers involves determining specific sampling frequencies and using inter-correlation between signals from different pathways to identify aliased frequencies, allowing for detection even with low peak power signals, by ensuring constant disparities and monotonic aliasing within a defined search band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple reception pathways with different sampling frequencies are used to remove frequency ambiguity, then frequency measurement accuracy is improved, but the signal-to-noise ratio becomes insufficient for detecting low peak power signals
Solution Approach 1:
The patent combines signals from multiple reception pathways with different sampling frequencies through correlation processing. By merging the information from these pathways and computing inter-correlation between the filtered signals, the system achieves both frequency ambiguity removal and improved signal-to-noise ratio, enabling detection of low peak power signals that would be undetectable in individual pathways alone.
2Measurement precision
If digital filtering is performed in banks of filters with like central frequency and width to process spectral aliasings, then frequency ambiguity is resolved, but detection of low peak power signals with long pulse duration becomes impossible due to insufficient signal-to-noise ratio
Solution Approach 1:
The patent employs a feedback mechanism where the correlation result from one pathway is used to guide the processing in other pathways. The system computes inter-correlation between signals from different pathways and uses this feedback information to enhance the detection of low peak power signals, allowing frequency ambiguity resolution while maintaining sufficient signal-to-noise ratio for detection.
3Adaptability or versatility
If sub-sampling is used in broadband digital receivers, then the receiver can process wide frequency bands, but spectral aliasings occur causing ambiguous frequency measurements
Solution Approach 1:
The patent segments the broadband signal processing into multiple reception pathways, each operating at a different sampling frequency. By dividing the wide frequency band into multiple sub-bands processed by different pathways and then combining the results through correlation processing, the system maintains broadband processing capability while resolving the frequency ambiguity caused by spectral aliasings in each individual pathway.
Data Source
AI summary
A digital receiver comprising at least two reception pathways, the method carries out a digital inter-correlation of the signals obtained as output from at least two filters of different central frequencies and different ranks, the rank and the central frequency of the filters being chosen as a function of a determined frequency-wise search domain. For a determined search domain, the various sampling frequencies of the reception pathways are chosen so that the ambiguous frequencies resulting from the spectral aliasings vary as a monotonic function of the true frequency of the signals.