SYSTEM AND METHOD FOR INTERFERENCE IDENTIFICATION AND FREQUENCY ALLOCATION

• US 20090097445A1
• Filed: 04/20/2007
• Published: 04/16/2009
• Est. Priority Date: 04/20/2006
• Status: Active Grant

• Current Assignee: Microchip Technology Incorporated
• Original Assignee: Wireless Audio IP BV
• Inventors: Lansbergen, Robertus Cornelis Wilhelmus, Moelker, Dignus-Jan
• Granted Patent: US 8,542,638 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

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 (1330,1340) for discriminating between interference caused by a Wireless Local Area Network and interference caused by other radio applications. The system does not allocate the frequencies associated with WLANs for use.

Claims

1. System for interference detection and identification, as well as frequency allocation for wireless systems, comprising interference detection means for detecting interference on wireless radio frequencies, the interference detection means comprising discrimination means (1330,1340) for discriminating between interference caused by a Wireless Local Area Network, herein after referred to as WLAN, and interference caused by other radio applications.

2. System according to claim 1 wherein the discriminating means (1330,1340) are adapted for discriminating between interference from a narrowband source and interference from a broadband source.

3. System according to claim 2 wherein the interference detection means are adapted for measuring the total interference in the frequency band of interest and the aggregate interference from narrowband signals in the frequency band and the discriminating means (1330,1340) are adapted for determining the difference between the total interference and the aggregate interference and based thereon deducing if the interference is from a narrowband source or a broadband source.

4. System according to claim 2, where the discriminating means (1330,1340) comprise at least the following elements:

a correlator (1330), measuring the correlation over a time distance, that is small compared to the main lobe of the autocorrelation of a WLAN signal;

a correlator (1330), measuring the correlation over a time distance, that is large compared to the main lobe of the autocorrelation of a WLAN signal;

wherein the discriminating means (1330,1340) are adapted for discriminating between narrowband and broadband interference from the respective correlator outputs.

5. System according to claim 1 wherein the discrimination means (1330,1340) comprise an intensity filter (660) for filtering interference statistics comprising:

a comparator comparing the interference statistics against a threshold resulting in a logical result at the output of the comparator indicative of the surpassing or not of the threshold and

a filter averaging the logical result over time.

6. System according to claim 1 wherein the discriminating means (1330,1340) are adapted for discriminating an interference caused by a WLAN-beacon.

7. System according to claim 6 wherein the discriminating means (1330,1340) are adapted to discriminate a repetition frequency of the WLAN-beacon.

8. System according to claim 7 wherein the discriminating means (1330,1340) are adapted for using the cross correlation of interference statistics in order to detect repetitive signals.

9. System according to any of the claims 6-8 wherein the discriminating means (1330,1340) are adapted to discriminate a duration of the WLAN-beacon by means of a filter.

10. System according to any of the preceding claims comprising means (1350) to determine a set of allowed frequencies being adapted for adding frequencies clear of interference to the set of allowed frequencies and adding interfered frequencies to the set of allowed frequencies only if no WLAN has been detected.

11. Method for interference detection and identification, as well as frequency allocation for wireless systems comprising the following steps:

detecting interference on wireless radio frequencies,

discriminating between interference caused by a Wireless Local Area Network and interference caused by other radio applications.

12. A computer program comprising computer program code means adapted to perform the following step, when said program is run on a computer:

based on detected interference on wireless audio frequencies discriminating between interference caused by a Wireless Local Area Network and interference caused by other radio applications.

13. A computer program as claimed in claim 12 embodied on a computer readable medium.

14. A carrier medium carrying the computer program of claim 12.