Compensation of quadrature imbalance in an optical coherent OQPSK receiver in presence of frequency offset

Abstract

In this paper, we describe the impact of quadrature imbalance (QI) in the presence of frequency offset in an optical coherent offset quadrature phase shift keying (OQPSK) receiver. Arbitrary conjugate misalignment was realized in a 2×4 90° optical hybrid, and the ellipse correction (EC) method of quadrature imbalance was applied in our simulation. In the case of transmission, the EC method can significantly improve the system performance.

Keywords

offset quadrature phase shift keying (OQPSK) / quadrature imbalance (QI) / ellipse fitting / frequency offset

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Acknowledgements

This work was supported by the Major State Basic Research Development Program of China (No. 2010CB328300), the National Natural Science Foundation of China (Grant No. 60777010), the National High Technology Research and Development Program of China (No. 2009AA01Z253), the Shuguang Fund (08SG05), China Postdoctoral Science Foundation (No. 20090460593), Shanghai Postdoctoral Science Foundation (No. 10R214116000), and the Postgraduate Innovative Fund (EYH1232043).

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg