Wideband Receiver Bluetooth Signal Detection

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Solution Overview

Problem

Bluetooth and WLAN networks operating in close proximity often experience interference, leading to degraded performance, and existing methods do not effectively address the coexistence issues in the 2.4 GHz ISM frequency band.

Innovation Solution

A method and system utilizing a wideband receiver to detect Bluetooth signals by scanning the 2.4 GHz ISM frequency band in sub-bands, performing a Fast Fourier Transform (FFT) on received energy data to determine the presence and channel of Bluetooth transmissions, allowing for efficient detection and differentiation from WLAN signals within a short scanning time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If Bluetooth and WLAN networks operate in close proximity using spread spectrum techniques, then both networks can function simultaneously, but their performance is degraded due to mutual interference

Engineering Contradiction:

Improvecoexistence capabilityVSAvoidnetwork performance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The system performs preliminary detection of Bluetooth signals before WLAN transmission begins by scanning the frequency band and analyzing energy levels. This preliminary action allows the WLAN system to identify ongoing Bluetooth transmissions and adjust its behavior accordingly, preventing interference before it degrades performance

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the frequency band for Bluetooth signals and uses this feedback information to dynamically adjust WLAN transmission parameters. When Bluetooth signals are detected, the system modifies WLAN behavior to avoid interference, creating a closed-loop control system that adapts to changing spectral conditions

Inventive Principle:

Principle #23Feedback

2Measurement precision

If a frequency band is scanned to detect Bluetooth signals, then accurate detection can be achieved, but the scanning time increases

Engineering Contradiction:

Improvedetection accuracyVSAvoidscanning time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The frequency band is divided into multiple sub-bands that are scanned sequentially rather than scanning the entire band at once. This segmentation allows the system to detect Bluetooth signals more quickly by focusing on specific frequency ranges, reducing overall scanning time while maintaining detection accuracy through systematic coverage of the complete band

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system performs energy detection on the entire frequency band first, then applies FFT analysis only to sub-bands where energy exceeds a threshold. This partial action approach avoids unnecessary processing in empty frequency regions, significantly reducing computation time while maintaining accurate detection where signals are present

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If Bluetooth receivers are activated continuously to detect signals, then no signals are missed, but power consumption increases

Engineering Contradiction:

Improvesignal detection reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of continuous activation, the Bluetooth receiver operates periodically by scanning the frequency band at intervals and detecting energy levels. This periodic operation maintains reliable signal detection capability while dramatically reducing average power consumption compared to continuous reception

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system uses the WLAN receiver's existing frequency scanning capability to simultaneously detect Bluetooth signals, rather than requiring a separate dedicated Bluetooth receiver to operate continuously. This self-service approach leverages existing hardware resources to maintain detection reliability without additional power consumption

Inventive Principle:

Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables rapid and accurate detection of Bluetooth signals, reducing unnecessary power consumption and preventing false activation of Bluetooth receivers, thereby improving coexistence and performance of Bluetooth and WLAN networks.

Implementation Method 1

performing a Fast Fourier Transform (FFT) on received energy data to determine the presence and channel of Bluetooth transmissions

Methodology Applied

Scientific EffectFast Fourier Transform:

Data Source

PatentEP2056486B1Method and system for detecting bluetooth signals utilizing a wideband receiver

Publication Date: 2012.03.21 BROADCOM INC

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AI summary

Aspects of a method and system for detecting Bluetooth signals utilizing a wideband receiver are provided. In this regard, a frequency band may be scanned by receiving signals on each of a plurality of sub-bands for an amount of time, the energy received in each band may be compared to a threshold, and whether each sub-band comprises a Bluetooth transmission may be determined based on a FFT. Additionally, the FFT may enable determining on which Bluetooth channel a detected transmission occurred. A FFT may be performed when energy detected in a sub-band is higher than a threshold. The sub-bands may each be a WLAN channel. A type of a detected Bluetooth transmission may be determined based on a number of scans in which the transmission is detected. Each sub-band may be received for less than or equal to 68µs divided by the number of sub-bands.