Distance to VSWR fault measurement

Patent metadata

Field	Value
Publication number	US-9755673-B2
Application number	US-201214437908-A
Country	US
Kind code	B2
Filing date	Oct 25, 2012
Priority date	Oct 25, 2012
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

The present invention addresses apparatuses, methods and computer program product for providing improved distance to fault measurement for voltage standing wave ratio (VSWR) on antenna line in networks. An embodiment of the present invention comprises the steps of transmitting a signal to a line to be tested, capturing a forward signal of the signal, capturing a reverse signal of the signal, separating the reflection of the signal in time domain via cross correlation of the forward signal and the reverse signal, and detecting a distance to fault in the line by searching and processing maximum peak position of the captured and separated signals.

First claim

What is claimed is:

1. A method, comprising:
detecting a voltage standing wave ratio at least by:
transmitting a signal to a line to be tested;
capturing a forward signal of the signal;
capturing a reverse signal of the signal; and
separating a reflection of the signal in a time domain via cross correlation of the forward signal and the reverse signal; and

detecting a distance to fault in the line by searching and processing maximum peak position of the captured and separated signals, wherein detecting the distance to fault is performed by processing performed to detect the voltage standing wave ratio, wherein the voltage standing wave ratio and the distance to fault detection are related to a reference point gained at calibration during manufacturing, and wherein the reference point was set by applying a defined reflection to a forward transmission chain, and
wherein the distance to fault is directly measured by network radio equipment comprising the forward transmission chain, and the forward signal and the reverse signal are simultaneously captured by hardware of the network radio equipment.

2. The method according to claim 1 , further comprising estimating a leakage from the forward to the reverse path for cancellation from the captured reverse reception data.

3. The method according to claim 2 , wherein estimating the leakage and its cancellation is carried out via an adaptive filter.

4. The method according to claim 1 , wherein separating the reflection of the signal is performed via a splitting device.

5. The method according to claim 4 , wherein the splitting device is a coupler or a circulator.

6. The method according to claim 4 , wherein the splitting device is located at an input or an output of a duplex filter.

7. The method according to claim 4 , wherein the line to be tested is an antenna line, and the splitting device is located at an antenna output.

8. The method according to claim 1 , wherein the forward signal and the reverse signal are simultaneously captured.

9. The method according to claim 1 , wherein the distance to fault information is transmitted to a maintenance network element.

10. The method of claim 1 , wherein the detecting a distance to fault in the line further comprises determining an actual distance to a fault by comparing a current distance to fault based on the detecting against a reference distance corresponding to the reference point.

11. The method of claim 10 , wherein the actual distance to the fault, s, is determined using the following:
s= ½· VF·c·n·Ts,

in which n=a number of taps corresponding to a difference of positions of a current reflection peak and a reference peak corresponding to the reference point, Ts=tap spacing, c˜3e8 m/s, and VF˜0.8 . . . 0.9 and is a velocity factor.

12. The method of claim 1 , wherein separating a reflection of the signal in a time domain farther comprises determining a return loss, RL, using the following:
RL˜pk reflection /pk reference [in dB]=−20·log 10 ( c pk ·pk reflection /pk reference ),

in which pk reflection is a peak magnitude of a current reflection peak, pk reference is a peak magnitude of a reference reflection peak corresponding to the reference point, and c pk represents a currently adjusted nominal power.

13. An apparatus, comprising:
network radio equipment comprising a forward transmission chain;
at least one memory comprising computer readable code; and
at least one processor;
the at least one memory and the computer program code configured, with the at least one processor, to cause the apparatus to perform at least the following:
detect a voltage standing wave ratio at least by:
transmit a signal to a line to be tested;
capture a forward signal of the signal and a reverse signal of the signal; and
separate the reflection of the signal in time domain via cross correlation of the forward signal and the reverse signal; and

detect a distance to fault in the line by searching and processing maximum peak position of the captured and separated signals, wherein detecting the distance to fault is performed by processing performed to detect the voltage standing wave ratio, wherein the voltage standing wave ratio and the distance to fault detection are related to a reference point gained at calibration during manufacturing, and wherein the reference point was set by applying a defined reflection to the forward transmission chain,
wherein the distance to fault is directly measured by the network radio equipment, and the forward signal and the reverse signal are simultaneously captured by hardware of the network radio equipment.

14. The apparatus according to claim 13 , wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to perform at least the following: estimate a leakage from the forward to the reverse path and cancel the leakage from the captured reverse reception data.

15. The apparatus according to claim 14 , wherein:
the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to perform at least the following: leakage; and
the cancelling of the leakage is carried out via an adaptive filter.

16. The apparatus according to claim 13 , wherein a splitting device as one of a coupler or a circulator performs the separating of the reflection of the signal in the time domain.

17. The apparatus according to claim 16 , wherein the splitting device is located at an input or an output of a duplex filter.

18. The apparatus according to claim 16 , wherein the line to be tested is an antenna line, and the splitting device is located at an antenna output.

19. The apparatus according to claim 13 , wherein the apparatus comprises a base transceiver station and wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to perform at least the following: detect the distance to fault by direct measurement by the base transceiver station.

20. The apparatus according to claim 13 , wherein at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to perform at least the following: transmit the distance to fault information to a maintenance network element.

21. A computer program product comprising a non-transitory a computer-readable medium having software code portions which, when the software code portions are executed by an apparatus, are configured to cause the apparatus to perform operations comprising:
detecting a voltage standing wave ratio at least by:
transmitting a signal to a line to be tested;
capturing a forward signal of the signal;
capturing a reverse signal of the signal; and
separating a reflection of the signal in a time domain via cross correlation of the forward signal and the reverse signal; and

detecting a distance to fault in the line by searching and processing maximum peak position of the captured and separated signals, wherein detecting the distance to fault is performed by processing performed to detect the voltage standing wave ratio, wherein the voltage standing wave ratio and the distance to fault detection are related to a reference point gained at calibration during manufacturing, and wherein the reference point was set by applying a defined reflection to a forward transmission chain,
wherein the distance to fault is d

Assignees

• Nokia Solutions & Networks Oy

Inventors

• Hellmann Jan
• Fleischer Marko
• Hueller Norbert
• Reichl Christian
• Kronwald Michael

Classifications

• H04B1/0466 Primary

  Fault detection or indication (H04B1/0483 takes precedence) · CPC title

• H04L5/14

  Two-way operation using the same type of signal, i.e. duplex · CPC title

• H04B17/101

  for measurement of specific parameters of the transmitter or components thereof · CPC title

• H04B17/103 Primary

  Reflected power, e.g. return loss · CPC title