Blind Equalization of Receiver In-Phase/Quadrature Skew in the Presence of Nyquist Filtering
As future systems move to higher order modulation formats and higher symbol rates the constraints on optical and electrical component become more stringent. Delay inside coherent receivers and ADCs caused by path length mismatch can lead severe performance degradation, especially for systems that employ Nyquist filtering. So far dedicated algorithms which measure and compensate the delays for each coherent receiver have been used. We propose a modified equalizer that is able to compensate for the delays on the fly while also equalizing the signal.