US 2006/0133805 A1Published application

Apparatus and method for detecting light source causing optical beat interference in subcarrier multiple access optical network

OwnerSeung-Hyun Jang, Chul-Soo Lee +2inventors

InventorsSeung-Hyun Jang, Chul-Soo Lee, Eui-Suk Jung, Byoung Kim

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Abstract

An apparatus for detecting a light source causing OBI noise in an SCMA optical network. Subcarrier power meters in the apparatus measure powers of subcarrier signals obtained by filtering a multiplexed optical signal transmitted from the subscriber terminals. A OBI power meter measures OBI noise power from an output of an optical receiver that receives the multiplexed optical signal. A noise occurrence determination unit sequentially changes output powers of light sources in the subscriber terminals if the minimum SNR between the subcarrier signal powers and the OBI noise power is less than a reference SNR, and determines that a light source, which causes a change in the OBI noise power in response to the change in the output power of the light source, is an OBI-causing light source.

Claims12

Dependent claims

An apparatus for detecting a light source causing OBI in a subcarrier multiple access (SCMA) optical network, the apparatus comprising:

a plurality of subcarrier power meters for measuring respective powers of subcarrier signals, corresponding respectively to a plurality of subscribers, obtained by filtering a multiplexed optical signal transmitted from a plurality of corresponding subscriber terminals in the SCMA optical network;
an optical beat interference (OBI) power meter for measuring OBI noise power from an output of an optical receiver that receives the multiplexed optical signal;
and
a noise occurrence determination unit for performing a control operation to sequentially change output powers of light sources provided in the plurality of subscriber terminals if a minimum signal to noise ratio (SNR) of SNRs between the powers of the subcarrier signals measured by the subcarrier power meters and the OBI noise power measured by the OBI power meter is less than a predetermined reference value, and determining that a light source among the light sources, which causes a change in the OBI noise power in response to the change in the output power of the light source, is an OBI-causing light source.

1 more element

An SCMA optical network system comprising:

a plurality of subscriber terminals for modulating input signals using unique subcarriers allocated respectively to the subscriber terminals and transmitting optical signals carrying the modulated signals;
an optical coupler for multiplexing the optical signals transmitted from the plurality of subscriber terminals into an optical signal;
a central office for performing a control operation to sequentially change output powers of a plurality of light sources provided in the plurality of subscriber terminals if a minimum SNR of SNRs between powers of a plurality of subcarrier signals included in the multiplexed optical signal and an OBI power is less than a predetermined reference value, and determining that a light source among the light sources, which causes a change in the OBI power in response to the change in the output power of the light source, is an OBI-causing light source.

A method for detecting a light source causing OBI in a subcarrier multiple access (SCMA) optical network, the method comprising the steps of:

a) measuring respective powers of subcarrier signals, corresponding respectively to a plurality of subscribers, obtained by filtering a multiplexed optical signal transmitted from a plurality of corresponding subscriber terminals in the SCMA optical network;
b) measuring OBI noise power from an output of an optical receiver that receives the multiplexed optical signal;
and
c) performing a control operation to sequentially change output powers of light sources provided in the plurality of subscriber terminals if a minimum signal to noise ratio (SNR) of SNRs between the measured powers of the subcarrier signals and the measured OBI noise power is less than a predetermined reference value, and determining that a light source among the light sources, which causes a change in the OBI noise power in response to the change in the output power of the light source, is an OBI-causing light source.

1 more element

Dependencies are inferred from the claim text.