Journal of Microwaves, Optoelectronics and Electromagnetic Applications
On-line version ISSN 2179-1074
PORTELA, Thiago F. et al. Analysis of signal processing techniques for optical 112 Gb/s DP-QPSK receivers with experimental data. J. Microw. Optoelectron. Electromagn. Appl. [online]. 2011, vol.10, n.1, pp.155-164. ISSN 2179-1074. http://dx.doi.org/10.1590/S2179-10742011000100016.
This paper evaluates several signal processing techniques for optical dual-polarization quadrature phase-shift keying (DP-QPSK) coherent receivers, using offline post-processing of experimental data. In addition to electronically separating the two polarization multiplexed signals, the investigated signal processing algorithms also compensate for chromatic dispersion (CD) and polarization mode dispersion (PMD). In particular, we investigate two distinct architectures: 1) Constant modulus algorithm (CMA) equalization followed by feedforward phase recovery. 2) Decision-directed least mean square (DD-LMS) equalization combined with decision-directed phase recovery. The interplay of both architectures with bulk dispersion compensators and carrier recovery algorithms is also analyzed.
Keywords : Blind equalization; coherent receiver; optical communications; polarizations demultiplexing.