SYSTEM AND METHOD FOR AUTOMATICALLY MEASURING UPLINK NOISE LEVEL OF DISTRIBUTED ANTENNA SYSTEM

• US 20130337750A1
• Filed: 03/14/2013
• Published: 12/19/2013
• Est. Priority Date: 06/14/2012
• Status: Active Grant

• Current Assignee: Advanced RF Technologies Incorporated
• Original Assignee: Advanced RF Technologies Incorporated
• Inventors: Ko, Young-Hoon
• Granted Patent: US 9,603,032 B2
• Time in Patent Office: Days
• US Class Current: 455/67.13
• CPC Class Codes: H04B 17/23 Indication means, e.g. displays, alarms, audible means
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A method of automatically measuring noise levels of a plurality of uplink paths in a Distributed Antenna System (DAS) includes: sequentially measuring a noise level of each uplink path of the plurality of uplink paths; extracting the noise level of each uplink path at a final end of the uplink path; detecting the noise level of each uplink path; and determining a status of each uplink path by comparing the detected noise level with a threshold value.

Claims

1. A method of automatically measuring noise levels of a plurality of uplink paths in a Distributed Antenna System (DAS), the method comprising:

sequentially measuring a noise level of each uplink path of the plurality of uplink paths;

extracting the noise level of each uplink path at a final end of the uplink path;

detecting the noise level of each uplink path; and

determining a status of each uplink path by comparing the detected noise level with a threshold value.

2. The method of claim 1, wherein the extracting the noise level of each uplink path comprises:

coupling the noise levels of the plurality of uplink paths; and

amplifying the coupled noise levels to a measurable level and filtering the amplified noise levels.

3. The method of claim 1, wherein the detecting the noise level of each uplink path comprises:

measuring the extracted noise levels; and

reporting the measured noise levels.

4. The method of claim 3, further comprising displaying the reported noise levels.

5. The method of claim 4, wherein the reported noise levels are displayed via a Graphic User Interface.

6. The method of claim 1, wherein the determining the status of each uplink path comprises:

comparing the detected noise level with an upper limit threshold value, and determining that the uplink path is abnormal if the detected noise level exceeds the upper limit threshold value, and determining that the uplink path is normal if the detected noise level does not exceed the upper limit threshold value.

7. The method of claim 1, wherein the determining the status of each uplink path comprises:

comparing the detected noise level with a lower limit threshold value, and determining that the uplink path has an abnormal reduced gain if the detected noise level is less than the lower limit threshold value, and determining that the uplink path has a normal reduced gain if the detected noise level is not less than the lower limit threshold value.

8. The method of claim 6, wherein the comparing the detected noise level with the upper limit threshold value comprises:

determining an external spurious signal input status or a self-oscillation status if an input switch on an input side of the uplink path is coupled to an antenna path of an external signal and the detected noise level exceeds the upper limit threshold value; and

determining an internal spurious abnormal status if the input switch is uncoupled from the antenna path and the detected noise level exceeds the upper limit threshold value.

9. The method of claim 8, wherein the determining the external spurious signal input status or the self-oscillation status comprises:

lowering an uplink gain of the DAS by an offset;

comparing the noise level with a comparison value obtained by reducing the upper limit threshold value by the offset; and

determining the external spurious signal input status if the noise level is higher than the comparison value and determining the self-oscillation status if the noise level is not higher than the comparison value.

10. The method of claim 9, further comprising:

generating an external spurious input alarm if the status of the uplink path is determined to be the external spurious signal input status; and

generating a self-oscillation alarm if the status of the uplink path is determined to be the self-oscillation status.

11. The method of claim 10, wherein each of the uplink paths corresponds to a remote unit (RU) of the DAS, and the method further comprises switching off power of the corresponding RU when the external spurious input alarm or the self-oscillation alarm is generated.

12. The method of claim 7, further comprising generating an uplink low gain alarm if the uplink path is determined to have the abnormal reduced gain.

13. The method of claim 12, wherein each of the uplink paths corresponds to a remote unit (RU) of the DAS, and the method further comprises switching off power of the corresponding RU after the uplink low gain alarm is generated.

14. The method of claim 1, further comprising:

receiving a request to measure the noise level of an uplink path of the plurality of uplink paths;

automatically measuring the noise level in real time; and

reporting the measured noise level.

15. The method of claim 1, wherein the noise levels are automatically measured and reported periodically according to a time cycle or at a specific time.

16. The method of claim 1, wherein the sequentially measuring the noise level of each uplink path comprises switching on an uplink path to be measured and switching off the other uplink paths of the plurality of uplink paths.

17. A Distributed Antenna System (DAS), comprising:

a switch configured to independently control switching on or off of uplink connection links between a plurality of remote units (RUs) and a head end of the DAS;

a coupler configured to couple a plurality of uplink noise signals of the uplink connection links, at a final end of an uplink path of the DAS;

a low noise amplifier (LNA) configured to perform low-noise amplification of the uplink noise signals coupled by the coupler;

a bandpass filter configured to filter the amplified noise signals received from the LNA;

a detector configured to detect the noise signals received from the LNA and the BPF; and

a control unit configured to determine a status of the uplink connection links,

wherein each of the RUs comprises an input switch configured to switch on or off a connection between the RU and an antenna for receiving an external signal.

18. The DAS of claim 17, further comprising an alarm generation unit configured to generate an alarm when a status of the uplink path is an abnormal status, and a power switch configured to switch off the alarm.