Method, apparatus, node device and network system for detecting optical signal-to-noise ratio

Patent metadata

Field	Value
Publication number	US-9621263-B2
Application number	US-201414493540-A
Country	US
Kind code	B2
Filing date	Sep 23, 2014
Priority date	Mar 23, 2012
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

The present invention discloses a method and an apparatus for detecting an optical signal-to-noise ratio, a node device, and a network system. The method includes: receiving a detected optical signal carrying amplified spontaneous emission ASE noise; detecting a first alternating current component and a first direct current component of the detected optical signal; acquiring first modulation information of the detected optical signal; acquiring first correction information corresponding to the first modulation information according to the first modulation information; and determining an optical signal-to-noise ratio OSNR of the detected optical signal according to the first alternating current component, the first direct current component, and the first correction information.

First claim

What is claimed is:

1. A method for detecting an optical signal-to-noise ratio, the method comprising:
receiving an optical signal carrying amplified spontaneous emission (ASE) noise;
detecting a first alternating current component and a first direct current component of the optical signal; wherein the optical signal is converted into an electric signal through a photoelectric detector in an optical receiver, the electric signal output by the photoelectric detector is split into two electric signals, one electric signal is sent to a low pass filter (LPF) for signal processing to acquire the first direct current component of the optical signal, the other electric signal is sent to a band pass filter (BPF) for signal processing to acquire the first alternating current component of the optical signal;
acquiring first modulation information of the optical signal;
acquiring first correction information corresponding to the first modulation information according to the first modulation information; and
determining an optical signal-to-noise ratio (OSNR) of the optical signal according to the first alternating current component, the first direct current component, and the first correction information.

2. The method according to claim 1 , wherein acquiring first modulation information of the optical signal comprises:
acquiring the first modulation information according to a high-frequency pilot signal carried in the optical signal.

3. The method according to claim 1 , wherein acquiring first modulation information of the optical signal comprises:
receiving a control signal sent by a control plane and used to indicate the first modulation information; and
acquiring the first modulation information according to the control signal.

4. The method according to claim 3 , further comprising:
establishing a correspondence table of modulation information and correction information, wherein an information type of the modulation information is the same as an information type of the first modulation information; and
wherein acquiring first correction information corresponding to the first modulation information comprises:
acquiring, according to the first modulation information, the first correction information by querying the correspondence table.

5. The method according to claim 4 , wherein establishing a correspondence table of modulation information and correction information comprises:
respectively receiving a first correction optical signal not carrying ASE noise, wherein at least one correction optical signal in the first correction optical signal has the first modulation information;
detecting a second alternating current component and a second direct current component of each correction optical signal in the first correction optical signal;
acquiring second modulation information of each correction optical signal, wherein an information type of the second modulation information is the same as the information type of the first modulation information;
determining second correction information corresponding to the second modulation information according to the second alternating current component and the second direct current component; and
establishing the correspondence table according to the second modulation information and the second correction information.

6. The method according to claim 5 , wherein determining an optical signal-to-noise ratio (OSNR) of the optical signal according to the first alternating current component, the first direct current component, and the first correction information comprises:
acquiring receiver parameters corresponding to a receiver that receives the optical signal; and
determining the OSNR of the optical signal according to the first alternating current component, the first direct current component, the receiver parameters, and the first correction information.

7. The method according to claim 6 , wherein acquiring receiver parameters corresponding to a receiver that receives the optical signal comprises:
receiving a second correction optical signal carrying ASE noise;
detecting a third alternating current component and a third direct current component of the second correction optical signal;
measuring a reference OSNR of the second correction optical signal;
acquiring third modulation information of the second correction optical signal and third correction information corresponding to the third modulation information, wherein an information type of the third modulation information is the same as the information type of the first modulation information; and
determining the receiver parameters according to the third alternating current component, the third direct current component, the reference OSNR, and the third correction information.

8. The method according to claim 6 , wherein determining the OSNR of the optical signal comprises:
based on the first alternating current component, the first direct current component, the first correction information, and the receiver parameters, determining the OSNR of the optical signal according to the following equations:

S
=

2
⁢

α
1

⁢

P
s
2

R

⁢

(

1
OSNR

+

B
0

2
⁢

R
·

OSNR
2

)

+

β
·

P
s
2

+

γ
⁢

⁢
and

E
=

α
2

·

P
s

⁡

(

1
+

1
OSNR

·

B
0

R

Assignees

• Huawei Tech Co Ltd

Inventors

• Wei Yijia
• Ni Juan
• Feng Zhiyong
• Deng Ning

Classifications

• H04B10/07953 Primary

  Monitoring or measuring OSNR, BER or Q · CPC title

• H04B2210/075

  using a pilot tone · CPC title

• H04B10/0775 Primary

  Performance monitoring and measurement of transmission parameters · CPC title