Signal Detection in High Noise Using Region Comparison

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Solution Overview

Problem

Conventional signal detection methods, such as the fixed interval matched filter approach, are inefficient and prone to false detection when dealing with low-level signals buried in high-level noise, especially when the noise is non-stationary, and struggle to accurately identify the time of arrival of such signals.

Innovation Solution

A signal detection system that includes a receiver and a preamble detection module capable of identifying a region of interest by comparing convolutions of left and right sides, and a multistage adaptive filter for message extraction, which can determine the approximate time of arrival and extract messages from data with noise amplitudes significantly higher than the signal amplitudes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional fixed interval matched filter approach is used, then signal detection is performed, but processing is time-consuming and resource-demanding

Engineering Contradiction:
Improvesignal detection speedVSAvoidprocessing time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The detection process is divided into multiple stages: initial coarse detection using energy detection, followed by refined detection using matched filter only in identified regions of interest. This segmentation allows the system to avoid applying computationally intensive matched filter processing to entire data sets, thereby reducing overall processing time and resource consumption while maintaining detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies the matched filter selectively only to regions of interest rather than processing the entire data set. This partial action approach processes only the necessary portions of the signal where detection is most likely to occur, significantly reducing computational load and processing time while still achieving complete signal detection.

Inventive Principle:
Principle #16Partial or excessive action

2Reliability

If conventional fixed interval matched filter approach is used, then signal detection is performed, but false detection occurs when noise is not stationary

Engineering Contradiction:
Improvedetection accuracyVSAvoidfalse detection from non-stationary noise
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adapts to non-stationary noise conditions by continuously monitoring signal characteristics and adjusting detection parameters. The region of interest identification and iterative refinement process allows the detector to adapt to changing noise statistics, maintaining high detection accuracy even when noise properties vary over time. This dynamic approach contrasts with fixed interval methods that assume stationary noise.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The iterative refinement process incorporates feedback mechanisms where detection results from one iteration inform the search strategy in subsequent iterations. The system uses feedback from initial detection attempts to refine region boundaries and adjust detection thresholds, thereby reducing false detections caused by non-stationary noise while maintaining sensitivity to actual signals.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If filtering techniques are used, then noise reduction is achieved, but low amplitude signals buried in high amplitude noise cannot be detected

Engineering Contradiction:
Improvesignal detection capabilityVSAvoidhigh amplitude noise masking low amplitude signals
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary energy detection and region of interest identification before applying the matched filter. This preliminary action identifies regions where signals are most likely present, allowing the subsequent matched filter processing to focus computational resources on these specific regions. This two-stage approach enables detection of low amplitude signals that would be masked by high amplitude noise in the overall signal.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The matched filter serves as an intermediary that correlates the received signal with a known signal template. This correlation process effectively extracts weak signal components from high amplitude noise by matching the signal's temporal and spectral characteristics. The filter acts as a mediator that translates the buried low amplitude signal into a detectable form while suppressing uncorrelated noise.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If conventional methods are used, then signal detection is attempted, but accurate time of arrival identification is difficult

Engineering Contradiction:
Improvetime of arrival accuracyVSAvoiddetection algorithm complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The detection process is segmented into coarse detection and fine detection stages. The coarse stage identifies the general region of interest containing the signal, while the fine stage performs precise time of arrival estimation within that region. This segmentation allows accurate time of arrival identification without requiring complex processing across the entire data set, thereby improving measurement precision while managing algorithm complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Complex time of arrival estimation algorithms are applied only within identified regions of interest rather than across the entire data set. This partial application of complex processing achieves accurate time of arrival identification while keeping overall computational complexity manageable by limiting the scope of intensive calculations to smaller, relevant portions of the signal.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS9722830B1Detection of low level communication signals in high level noise
Publication Date: 2017.08.01 THE CHARLES STARK DRAPER LABORATORY INC
  • US9722830B1 patent drawing
  • US9722830B1 patent drawing
  • US9722830B1 patent drawing

AI summary

The disclosure is directed to a signal detection system. The system includes a receiver configured to receive data comprising noise and a signal having an amplitude lower than that of the noise received by the receiver. The system also includes a detection module configured to receive the data received by the receiver, define a region of interest of the data, compare a plurality of portions of the region of interest, and identify a portion of the region of interest that is more likely to contain the signal.