We propose - as a modification of the optical (RF) pilot scheme -a balanced phase modulation between two polarizations of the optical signal in order to generate correlated equalization enhanced phase noise (EEPN) contributions in the two polarizations. The method is applicable for n-level PSK system. The EEPN can be compensated, the carrier phase extracted and the nPSK signal regenerated by complex conjugation and multiplication in the receiver. The method is tested by system simulations in a single channel QPSK system at 56 Gb/s system rate. It is found that the conjugation and multiplication scheme in the Rx can mitigate the EEPN to within 1/2 orders of magnitude. Results are compared to using the Viterbi-Viterbi algorithm to mitigate the EEPN. The latter method improves the sensitivity more than two orders of magnitude. Important novel insight into the statistical properties of EEPN is identified and discussed in the paper.
Bibliographical note© 2013 OSA.
This paper was published in Optics express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-21-10-12351. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.
Support of the Engineering and Physical Sciences Research Council (EPSRC) project UNLOC, EP/J017582/1 and FP7-PEOPLE-2012-IAPP (project GRIFFON, No 324391) is acknowledged.
Jacobsen, G., Xu, T., Popov, S., & Sergeyev, S. (2013). Study of EEPN mitigation using modified RF pilot and Viterbi-Viterbi based phase noise compensation. Optics Express, 21(10), 12351-12362. https://doi.org/10.1364/OE.21.012351