Reducing Equalization-enhanced Phase Noise via Carrier Phase Recovery in the Presence of Variable Matched-filter Bandwidth

Equalization-enhanced phase noise (EEPN) can be a major limitation in coherent receivers, when the large accumulated dispersion is compensated for high baud rate signals. One unique feature of EEPN is that its phase component can be larger than the amplitude one. Then the carrier phase recovery algorithm can squeeze the phase component, and therefore, the overall EEPN is also reduced. In this paper, we show that the EEPN and its ovality are both affected by the matched filter bandwidth. The reduction of EEPN by BPS can be more pronouncing when the bandwidth is larger.