# US 9,002,291 B2 · Standing wave detection method, standing wave detection apparatus and base station

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- Number: US 9,002,291 B2
- Document ID: US9002291B2
- Status: Granted
- Kind: B2
- Application number: 13/572,595
- Filed: 2012-08-10
- Published: 2012-12-06
- Granted: 2015-04-07
- Earliest claimed: 2010-02-11
- Assignees: Huawei Technologies Co., Ltd.
- Applicants: Shaofeng Xu; Zhengxiang Ma; Siqing Ye; Wei Wang; Pengfei Luo
- Inventors: Shaofeng Xu; Zhengxiang Ma; Siqing Ye; Wei Wang; Pengfei Luo
- Web page: https://patentgrep.com/patent/US9002291B2

## CPC

- H04B 1/0466: {Fault detection or indication (H04B1/0483 takes precedence)}
- H04B 17/103: {Reflected power, e.g. return loss}
- H04B: TRANSMISSION

## Abstract

A standing wave detection method, a standing wave detection apparatus, and a base station are disclosed. The method includes collecting, a feedback signal from a feedback path of a base station which uses a baseband multi-tone signal as a transmission signal; performing calibration on the feedback signal by using stored calibration data to obtain a reflected signal in the feedback signal; and obtaining a standing wave detection value according to the transmission signal and the reflected signal that is in the feedback signal.

## Claims

### Claim 1

A standing wave detection method, comprising:
collecting a feedback signal from a feedback path of a base station that uses a baseband multi-tone signal as a transmission signal;
performing calibration processing on the feedback signal by using stored calibration data to obtain a reflected signal in the feedback signal, wherein the stored calibration data includes baseband multi-tone signals and corresponding feedback signals respectively collected when a calibration point is in a state of open-circuited, short-circuited, and matched load; and
obtaining a standing wave detection value according to the transmission signal and the reflected signal that is in the feedback signal.

### Claim 2 (depends on 1)

The standing wave detection method according to claim 1, wherein obtaining the standing wave detection value comprises:
obtaining a rectified time domain system transmission function according to the transmission signal and the reflected signal;
obtaining a peak value of the reflected signal according to a curve of the time domain system transmission function; and
obtaining a location of a cable fault point according to the peak value.

### Claim 3 (depends on 1)

The standing wave detection method according to claim 1, wherein obtaining the standing wave detection value comprises:
obtaining a maximum value of the feedback signal through averaging amplitude of the corresponding feedback signals;
comparing the reflected signal in the feedback signal with the maximum value of the feedback signal to obtain a reflectance; and
obtaining a standing wave ratio according to the reflectance.

### Claim 4 (depends on 2)

The standing wave detection method according to claim 2, wherein the obtaining the location of a cable fault point according to the peak value comprises:
obtaining the location of the cable fault point according the peak value and a cable fault point calculation formula
L
=
(
Peak
-
1
N
FFT
-
1
)
⁢
(
N
F
-
1
f
1
-
f
2
)
⁢
v
p
;
where Peak is the peak value of the reflected signal, f1 is a start frequency point of frequency sweeping, f2 is an end frequency point of the frequency sweeping, NF is a number of frequency sweeping points; NFFT is a number of points in FFT transform; and Vp is a propagation velocity in a cable, wherein the propagation velocity has a speed close to a speed of light.

### Claim 5

A standing wave detection apparatus, comprising:
a collecting module, configured to collect a feedback signal from a feedback path of a base station that uses a baseband multi-tone signal as a transmission signal;
a calibrating module, configured to perform calibration processing on the feedback signal by using stored calibration data to obtain a reflected signal in the feedback signal, wherein the stored calibration data comprises baseband multi-tone signals and corresponding feedback signals respectively collected when a calibration point is in a state of open-circuited, short-circuited, and matched load; and
a detecting module, configured to obtain a standing wave detection value according to the transmission signal and the reflected signal that is in the feedback signal.

### Claim 6 (depends on 5)

The standing wave detection apparatus according to claim 5, wherein the detecting module comprises:
a rectifying submodule configured to obtain a rectified time domain system transmission function according to the transmission signal and the reflected signal;
a peak value obtaining submodule configured to obtain a peak value of the reflected signal according to a curve of the time domain system transmission function; and
a fault point location obtaining submodule configured to obtain a location of a cable fault according to the peak value.

### Claim 7 (depends on 5)

The standing wave detection apparatus according to claim 5, wherein the detecting module comprises:
an averaging submodule configured to obtain a maximum value of the feedback signal through averaging amplitude of the corresponding feedback signals;
a comparing submodule configured to compare the reflected signal in the feedback signal with the maximum value of the feedback signal to obtain a reflectance; and
a standing wave ratio obtaining submodule configured to obtain a standing wave ratio according to the reflectance.

### Claim 8 (depends on 5)

The standing wave detection apparatus according to claim 5, wherein the standing wave detection apparatus comprises an instrument.

### Claim 9

A computer program product comprising a computer readable non-transitory storage medium storing program code thereon for use by a base station, the program code comprising:
instructions for collecting a feedback signal from a feedback path of a base station that uses a baseband multi-tone signal as a transmission signal;
instructions for performing calibration processing on the feedback signal by using stored calibration data to obtain a reflected signal in the feedback signal, wherein the stored calibration data includes baseband multi-tone signals and corresponding feedback signals respectively collected when a calibration point is in a state of open-circuited, short-circuited, and matched load; and
instructions for obtaining a standing wave detection value according to the transmission signal and the reflected signal that is in the feedback signal.

### Claim 10 (depends on 9)

The computer program product according to claim 9, wherein the instructions for obtaining the standing wave detection value according to the transmission signal and the reflected signal that is in the feedback signal comprise:
instructions for obtaining a rectified time domain system transmission function according to the transmission signal and the reflected signal;
instructions for obtaining a peak value of the reflected signal according to a curve of the time domain system transmission function; and
instructions for obtaining a location of a cable fault point according to the peak value.

### Claim 11 (depends on 9)

The computer program product according to claim 9, wherein the instructions for obtaining the standing wave detection value according to the transmission signal and the reflected signal that is in the feedback signal comprise:
instructions for obtaining a maximum value of the feedback signal through averaging amplitude of the corresponding feedback signals;
instructions for comparing the reflected signal in the feedback signal with the maximum value of the feedback signal to obtain a reflectance; and
instructions for obtaining a standing wave ratio according to the reflectance.

### Claim 12 (depends on 10)

The computer program product according to claim 10, wherein the instructions for obtaining a location of a cable fault point according to the peak comprise:
instructions for obtaining the location of the cable fault point according the peak value and a cable fault point calculation formula
L
=
(
Peak
-
1
N
FFT
-
1
)
⁢
(
N
F
-
1
f
1
-
f
2
)
⁢
v
p
;
where Peak is the peak value of the reflected signal, f1 is a start frequency point of frequency sweeping, f2 is an end frequency point of the frequency sweeping, N F is a number of frequency sweeping points; NFFT is a number of points in FFT transform; and Vp is a propagation velocity in a cable, wherein the propagation velocity has a speed close to a speed of light.