E. Ip, A. P. Lau, D. J. Barros, and J. M. Kahn, Coherent detection in optical fiber systems, Optics Express, vol.16, issue.2, pp.753-791, 2008.
DOI : 10.1364/OE.16.000753

X. Liu, Receiver sensitivity improvement in optical DQPSK and DQPSK/ASK through data-aided multisymbol phase estimation, Proc. ECOC, Th.4.4.5, 2006.

I. Fatadin, Compensation of Quadrature Imbalance in an Optical QPSK Coherent Receiver, IEEE Photonics Technology Letters, vol.20, issue.20, pp.1733-1735, 2008.
DOI : 10.1109/LPT.2008.2004630

S. H. Chang, Impact of Quadrature Imbalance in Optical Coherent QPSK Receiver, IEEE Photonics Technology Letters, vol.21, issue.11, pp.709-711, 2009.
DOI : 10.1109/LPT.2009.2016759

C. S. Petrou, Quadrature Imbalance Compensation for PDM QPSK Coherent Optical Systems, IEEE Photonics Technology Letters, vol.21, issue.24, pp.1876-1878, 2009.
DOI : 10.1109/LPT.2009.2034750

B. Razavi, Design considerations for direct-conversion receivers, IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, vol.44, issue.6, pp.45-52, 1997.
DOI : 10.1109/82.592569

J. Proakis, Digital Communications, Chap. 5 and Chap, 2000.