Patent ID: 8005358
Filing Date: 2011-08-23
Classification: H04B,H04J

Abstract:
1. A line monitoring system for an optical communication system comprising: a laser transmitter, said laser transmitter configured for providing an optical output at a carrier wavelength; a code generator configured to generate a test code, said code generator being coupled to said laser transmitter for modulating said test code on said optical output to provide a test signal representative of said test code, said test signal being provided for coupling to an optical path whereby said test signal is returned to the line monitoring system through a first loopback path as a first returned test signal and said test signal is returned to the line monitoring system through a second loopback path as a second returned test signal; a wavelength dither generator coupled to said laser transmitter, said wavelength dither generator being configured for generating a wavelength dither signal for dithering said carrier wavelength; and a correlator for simultaneously receiving overlapping portions of said first and second returned test signals, said wavelength dither generator being configured to vary said carrier wavelength along a code length of said test code so that said overlapping portions of said first and second returned test signals occupy different wavelengths thereby suppressing beat noise in said first and second returned test signals.