# US 8,542,638 B2 · System and method for interference identification and frequency allocation

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- Number: US 8,542,638 B2
- Document ID: US8542638B2
- Status: Granted
- Kind: B2
- Application number: 12/297,828
- Filed: 2007-04-20
- Published: 2009-04-16
- Granted: 2013-09-24
- Earliest claimed: 2006-04-20
- Assignees: Microchip Technology Incorporated
- Applicants: Dignus-Jan Moelker; Robertus Cornelis Wilhelmus Lansbergen
- Inventors: Dignus-Jan Moelker; Robertus Cornelis Wilhelmus Lansbergen
- Web page: https://patentgrep.com/patent/US8542638B2

## CPC

- H04W 16/14: Spectrum sharing arrangements {between different networks}
- H04W 24/00: Supervisory, monitoring or testing arrangements
- H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA
- H04W 72/541: using the level of interference
- H04W 84/12: WLAN [Wireless Local Area Networks]
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A system for interference detection and identification, as well as frequency allocation is described. It contains interference detection means for detecting interference on wireless radio frequencies. The interference detection means comprising discrimination means for discriminating between interference caused by a Wireless Local Area Network (WLAN) and interference caused by other radio applications. The system does not allocate the frequencies associated with WLANs for use.

## Claims

### Claim 1

A system comprising an interference detection means for detecting interference on wireless radio frequencies, wherein the interference detection means comprises a discrimination means for:
discriminating between interference caused by a Wireless Local Area Network, herein after referred to as WLAN, and interference caused by other radio applications;
discriminating between interference from a narrowband source and interference from a broadband source, wherein when the discrimination means determines a detected interference is from a broadband source the discrimination means determines the detected interference is caused by a WLAN; and
wherein the interference detection means is adapted for measuring a total interference in a frequency band of interest and an aggregate interference from narrowband signals in the frequency band of interest, and wherein the discrimination means is adapted for determining the difference between the total interference and the aggregate interference and based thereon deducing if the detected interference is from a narrowband source or a broadband source.

### Claim 2

A system comprising an interference detection means for detecting interference on wireless radio frequencies, wherein the interference detection means comprises a discrimination means for:
discriminating between interference caused by a Wireless Local Area Network, herein after referred to as WLAN, and interference caused by other radio applications;
discriminating between interference from a narrowband source and interference from a broadband source, wherein when the discrimination means determines a detected interference is from a broadband source the discrimination means determines the detected interference is caused by a WLAN; and
wherein the discrimination means comprises a correlator for measuring correlations of power measurements over delay times that are small compared to a main lobe of an autocorrelation of a WLAN signal and that are large compared to the main lobe of the autocorrelation of a WLAN signal, wherein the discrimination means is adapted for discriminating between narrowband and broadband interference from the measured correlations.

### Claim 3

A system comprising an interference detection means for detecting interference on wireless radio frequencies, wherein the interference detection means comprises a discrimination means for:
discriminating between interference caused by a Wireless Local Area Network, herein after referred to as WLAN, and interference caused by other radio applications;
discriminating between interference from a narrowband source and interference from a broadband source, wherein when the discrimination means determines a detected interference is from a broadband source the discrimination means determines the detected interference is caused by a WLAN; and
wherein the discrimination means comprises an intensity filter for filtering interference statistics, wherein the intensity filter comprises:
a comparator for comparing the interference statistics against a threshold resulting in a logical result at the output of the comparator which is indicative of surpassing or not of the threshold; and
a filter averaging the logical result over time.