Frequency Sub-band Detection for Wireless Microphones

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Solution Overview

Problem

Current methods for detecting wireless microphone signals in cognitive radio systems are inefficient due to the lack of distinct characteristics in their signals, making it difficult to protect them from interference, especially in narrowband contexts where broadband solutions are not precise enough.

Innovation Solution

A process and device for detecting a frequency sub-band within a broader frequency band by performing frequential analysis, breaking down the signal into smaller sub-bands, determining a criterion based on energy and autocorrelation coefficients, and deciding on signal presence in each sub-band, allowing for more precise and faster detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If broadband detection solutions are used to detect wireless microphone signals, then the detection coverage is improved, but the detection precision deteriorates

Engineering Contradiction:
Improvedetection coverageVSAvoiddetection precision
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent divides the broadband frequency range into multiple narrowband sub-bands. Each sub-band is detected separately using detection algorithms that operate independently on each frequency segment. This segmentation allows the system to maintain broad coverage while achieving high precision in each individual sub-band, resolving the contradiction between coverage area and measurement precision.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If narrowband detection is used for each TV channel, then the detection precision is improved, but the detection speed deteriorates

Engineering Contradiction:
Improvedetection precisionVSAvoiddetection speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent merges multiple narrowband detection operations into a unified broadband detection framework. By processing multiple sub-bands simultaneously using parallel detection algorithms and combining the results, the system achieves detection speeds comparable to broadband methods while maintaining the precision of narrowband analysis. This merging resolves the contradiction between precision and productivity.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If multiple detection algorithms are combined to improve detection accuracy, then the detection reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvedetection reliabilityVSAvoidalgorithm complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies different detection algorithms to different frequency sub-bands based on their specific characteristics. Instead of using a single complex algorithm across the entire bandwidth or uniformly complex algorithms in each sub-band, the system selects appropriate detection methods for each local frequency region. This local quality approach improves overall detection reliability while keeping the complexity of each individual algorithm manageable.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS9008708B2Process and device for detection of a frequency sub-band in a frequency band and communications equipment comprising such a device
Publication Date: 2015.04.14 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • US9008708B2 patent drawing
  • US9008708B2 patent drawing
  • US9008708B2 patent drawing

AI summary

The invention relates to a process for detection of a signal in a frequency sub-band of a frequency band of an acquired signal y(t), the process comprising:acquisition of the signal y(t) in a frequency band;frequential analysis of said acquired signal y(t) to obtain at least one frequential signal Y with NFFT frequential components;breakdown into M frequency sub-bands i of size N of the frequential signal Y, the size of each frequency sub-band being a function of the bandwidth of the signal to be detected;determination, in the frequential domain, for each frequency sub-band, of a criterion Ti, i=1, . . . , M as a function of the energy of the signal in the frequency sub-band i and of the coefficient two of the autocorrelation function of the signal in the frequency sub-band i;decision, as a function of the criterion Ti, to determine whether a signal is detected in the sub-band i.