A new blind frequency offset estimation method based on cyclic prefix and virtual subcarriers in coherent optical orthogonal frequency division multiplexing (CO-OFDM) system is presented. It is able to estimate the fractional part and integral part of frequency offset at the same time. Its estimation range is about [?3.5 GHz, 3.5 GHz]. The influence of the integral frequency offset is comprehensively analyzed in COOFDM system. Its performances in the additive white Gaussian noise (AWGN) channel and the dispersive channel are investigated, respectively. Simulation results indicate that even in the dispersive channel, when the optical signal-to-noise ratio (OSNR) is low, it can still work very well.
© 2010 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
(060.5060) Fiber optics and optical communications : Phase modulation
Yaojun Qiao, Zhansheng Wang, and Yuefeng Ji, "Blind frequency offset estimation based on cyclic prefix and virtual subcarriers in CO-OFDM system," Chin. Opt. Lett. 8, 888-893 (2010)