We propose a blind quadrature imbalance (QI) compensation algorithm based on the statistical properties of I and Q signals in a receiver. The algorithm estimates the QI parameters of a receiver by calculating the mean, variance, and correlation coefficient of I and Q components. Then, the estimated imbalance parameters are adopted to compensate for the QI in the receiver. Simulation results show that the Q factor is considerably optimized by the application of the QI compensation algorithm in an 80-Gb/s Pol-Mux coherent optical quadrature phase-shift keying (CO-QPSK) system. Compared with conventional algorithms, the proposed algorithm exhibits better performance when the phase deviation from QI exceeds ±15°.
© 2012 Chinese Optics Letters
(060.0060) Fiber optics and optical communications : Fiber optics and optical communications
(060.1660) Fiber optics and optical communications : Coherent communications
(060.2330) Fiber optics and optical communications : Fiber optics communications
(070.6020) Fourier optics and signal processing : Continuous optical signal processing
Fiber Optics and Optical Communications
Yaojun Qiao, Yanfei Xu, Lujiao Li, and Yuefeng Ji, "Quadrature imbalance compensation algorithm based on statistical properties of signals in CO-QPSK system," Chin. Opt. Lett. 10, 120601-120601 (2012)