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 feed forward 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.
|Number of pages||10|
|Journal||Journal of Microwaves and Optoelectronics|
|Publication status||Published - Jun 2011|
- Blind equalization
- Coherent receiver
- Optical communications
- Polarizations demultiplexing