Signal Detection Apparatus Cyclic Autocorrelation Shared Frequency Band
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Solution Overview
Problem
Current signal detection methods in shared frequency bands face challenges in accurately detecting multiple signals without interference, particularly due to high calculation loads and reduced detection rates of weak signals, especially when different signals have varying reception levels.
Innovation Solution
A signal detection apparatus that calculates cyclic autocorrelation values for each candidate signal, utilizing a common area where error components are common across multiple signals to reduce calculation load and enhance weak signal detection, by using the second-order cyclic autocorrelation function and frequency correlation characteristics as waveform features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If feature detection is performed for multiple candidate signals, then detection accuracy improves, but calculation load increases significantly
Solution Approach 1:
The patent segments the detection process into two stages: first detecting strong signals and removing them from the mixture, then detecting weaker signals in the residual. This segmentation reduces the calculation load for each detection stage while maintaining overall detection accuracy for multiple signals.
Solution Approach 2:
The patent performs preliminary detection and removal of strong signals before detecting weaker signals. By eliminating strong signal components first, the subsequent detection of weak signals becomes computationally simpler and more accurate, as the dominant interference is already removed.
2Reliability
If strong signals are present in the receiver, then signal detection becomes easier, but weak signal detection rate decreases due to feature burial
Solution Approach 1:
The patent extracts and removes strong signal components from the received signal mixture before detecting weak signals. By taking out the dominant strong signals, the weak signals that were previously buried in the features of strong signals become detectable, thereby improving weak signal detection rate while maintaining strong signal detection reliability.
3Productivity
If multiple radio systems share the same frequency band, then frequency utilization efficiency improves, but signal detection complexity increases
Solution Approach 1:
The patent segments the complex multi-signal detection problem into sequential stages, detecting and removing one signal at a time starting from the strongest. This segmentation approach enables multiple radio systems to share the frequency band effectively while keeping the detection complexity manageable through iterative simple detection steps.
Data Source
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AI summary
A signal detection apparatus includes: a unit configured to select a particular detection target signal from among plural candidates of detection target signals; a unit configured to calculate a cyclic autocorrelation value at a center coordinate point specified by at least a cyclic parameter and a shift parameter of the particular detection target signal; a unit configured to calculate a cyclic autocorrelation value of each of (L-1) coordinate points belonging to a common area that is used commonly for different detection target signals; a unit configured to calculate a test statistic of the particular detection target signal; and a unit configured to determine presence or absence of the particular detection target signal according to a comparison result between the test statistic and a threshold, wherein the test statistic is calculated by using the cyclic autocorrelation value in each of the (L-1) coordinate points belonging to the common area.