Cyclic Auto-Correlation Signal Detection Without Noise Estimation

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Solution Overview

Problem

Conventional cyclo-stationary based detection methods for cognitive radios require an infinite number of samples and accurate noise power knowledge, making them unreliable due to finite sampling and noise uncertainty.

Innovation Solution

The method calculates two test statistics based on cyclic auto-correlation properties of the received signal, comparing them to determine the presence of a data signal, eliminating the need for noise power estimation and improving detection reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional cyclo-stationary based detection methods are used, then signal detection capability is improved, but the requirement for infinite samples and accurate noise power knowledge makes the system unreliable in practice

Engineering Contradiction:
Improvesignal detection accuracyVSAvoiddetection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent transforms the detection approach by changing the mathematical parameters used - specifically using ratio of cyclic auto-correlations instead of absolute cyclic auto-correlation values. This parameter transformation eliminates the need for noise power estimation and infinite samples, as the ratio operation inherently normalizes the signal and cancels out common noise components, making the detection reliable with finite samples and unknown noise power

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The detection method becomes self-sufficient by using the signal's own cyclic auto-correlation properties for detection. The ratio of cyclic auto-correlations at different cyclic frequencies allows the system to detect signals without external reference to noise power levels, making the system self-adapting to varying noise conditions without requiring separate noise estimation mechanisms

Inventive Principle:
Principle #25Self-service

2Ease of operation

If finite number of samples are used, then practical implementation is enabled, but perfect cyclic auto-correlation cannot be achieved

Engineering Contradiction:
Improvepractical implementabilityVSAvoidcyclic auto-correlation accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

Instead of requiring perfect cyclic auto-correlation that would demand infinite samples, the patent applies partial action by using a finite number of samples and accepting approximate cyclic auto-correlation values. The ratio operation then extracts the essential detection information from these partial correlations, achieving sufficient detection accuracy without the excessive sample requirements of conventional methods

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If accurate noise power knowledge is required, then detection threshold can be set accurately, but noise uncertainty from multiple sources degrades performance

Engineering Contradiction:
Improvethreshold setting accuracyVSAvoidnoise estimation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential detection information by taking the ratio of cyclic auto-correlations at different cyclic frequencies. This extraction process removes the noise power component from the detection equation, as the ratio operation cancels out the common noise term present in both numerator and denominator, eliminating the need for separate noise power estimation and its associated complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS20110249776A1Method for determining as to whether a received signal includes a data signal
Publication Date: 2011.10.13 AGENCY FOR SCI TECH & RES
  • US20110249776A1 patent drawing
  • US20110249776A1 patent drawing
  • US20110249776A1 patent drawing

AI summary

A method of determining as to whether a received signal includes a data signal is provided. The method provided includes determining a first value based on a cyclic auto-correlation of the received signal and determining a second value based on the cyclic auto-correlation of the received signal. The method provided further includes determining as to whether a received signal includes a data signal based on a comparison of the first value and the second value.