In-band SNR measurement based on spectral correlation

摘要

Method and apparatus for estimating the in-band signal-to-noise SNR in optical channels by processing a spectral correlation density function (SCDF) of a noisy optical or electrical signal x(t). The method and apparatus are based on the fact that synchronous data signals with a fixed symbol rate 1/T and the channel noise have different correlation properties. The method allows separation of signal and noise components in optical and electrical transmission systems with high spectral efficiency where signal spectrum and noise spectrum are completely overlapping.