An IIR adaptive electronic equalizer for polarization multiplexed fiber optic communication systems

Abstract

An electronic digital equalizer for polarization multiplex coherent fiber optic communication systems is designed to compensate polarization mode dispersion (PMD) and residual chromatic dispersion (CD) of transmission channel. The proposed equalizer is realized with fraction spaced infinite impulse response (IIR) butterfly structure with 21 feedforward taps and 2 feedback taps. Compared with finite impulse response (FIR) structure, this structure can reduce implementation complexity of hardware under the same condition. To keep track of the random variation of channel characteristics, the filter weights are updated by least mean square (LMS) algorithm. The simulation results show that the proposed equalizer can compensate residual chromatic dispersion (CD) of 1600 ps/nm and differential group delay (DGD) of 90 ps simultaneously, and also can increase the PMD and residual CD tolerance of the whole communication system.

Keywords

Finite Impulse Response / Little Mean Square / Quadrature Amplitude Modulation / Infinite Impulse Response / Chromatic Dispersion

References

[1] IEEE Std 802.3ba-2010

[2] JoindotM., GosselinS.. C. R. Physique, 2008, 9: 914

[3] IpE., LauA. P. T., BarrosD. J. F., KahnJ. M.. Optics Express, 2008, 16: 753

[4] FritzscheD., DuthelT., SchäfferC. G.. Optics Communications, 2008, 281: 2429

[5] Remmersmann Christian, Westhäuser Matthias, Pachnicke Stephan, Gernot Gger, Gabriel Kerner and Peter M. Krummrich, Equalization of First and Second Order PMD in 100 GBit/s PolMux Transmission Using Optical Butterfly FIR Filters. OThJ · PMD Compensation, OFC, 2010.

[6] Simon Haykin, Adaptive Filter Theory (4th Edition). Prentice Hall, 2001.

[7] XuT., JacobsenG., PopovS., LiJ., WangK., FribergA. T.. Optics Communications, 2010, 283: 963

[8] ShaoY.-f., HeZ.-x., ChiN., FangW.-l., ZhangJ.-w., HuangB.. Joumal of Optoelectronics · Laser, 2010, 21: 1316

[9] YanH., GuifangL.. Optics Express, 2005, 13: 7527

[10] ZhaoY., QiaoY.-j., JiY.-f.. Joumal of Optoelectronics · Laser, 2010, 21: 1651