Mitigation of Imperfect Carver-Induced Phase Distortions in a Coherent PM-RZ-QPSK Receiver
- Resource Type
- Periodical
- Authors
- Chung, H. S.; Chang, S. H.; Kim, K.
- Source
- Journal of Lightwave Technology J. Lightwave Technol. Lightwave Technology, Journal of. 28(24):3506-3511 Dec, 2010
- Subject
- Communication, Networking and Broadcast Technologies
Photonics and Electrooptics
Phase distortion
Optical noise
Signal to noise ratio
Optical transmitters
Optical distortion
Frequency estimation
Estimation
100 Gb/s
coherent
return-to-zero quadrature- phase-shift-keying (RZ-QPSK)
pulse carver
- Language
- ISSN
- 0733-8724
1558-2213
The impact of phase distortions caused by imperfect return-to-zero (RZ) pulse carving on 112 Gb/s polarization-multiplexed (PM)-RZ-quadrature-phase-shift-keying (QPSK) is investigated, and mitigation of the phase distortion is demonstrated by using digital signal processing technique. We show that carver-induced phase distortion causes an error in frequency offset estimation as well as sensitivity degradation. Based on the periodicity of distortion pattern, the phase distortion is compensated by estimating mean phase distortions for even and odd symbols after block phase estimation and subtracting these values from original symbols. The optical SNR penalty measured at 112 Gb/s PM-RZ-DQPSK signal is reduced from 3.8 to 1.1 dB with the help of correction algorithm.