Abstract
Reduced-guard-interval (RGI) coherent optical orthogonal frequency division multiplexing (CO-OFDM) has been considered as a promising technique for high-speed optical fiber communication systems due to its simple equalization scheme and tolerance to residual chromatic dispersion (CD) [1]. However, one serious drawback of RGI OFDM is the high side lobes due to the ‘brick-wall’ filtering, which leads to higher vulnerability to intercarrier interference (ICI) due to frequency offset, laser and nonlinear phase noise. As a result, RGI CO-OFDM transmission suffers seriously from equalization-enhanced phase noise (EEPN) which is a complicated interplay of laser phase noise, nonlinear phase noise and digital CD equalizer [2]. Here, we show, for the first time, that the impact of EEPN can be significantly mitigated by employing a specific version of OFDM called filter bank multicarrier (FBMC) in which the retangular pulse shape is replaced by a modified raised cosine function. Unlike OFDM signal, FBMC guarantees the orthogonality only in real fields where the receiverd signal is interfered by the so-called imaginary interference [3-4]. Therefore, the channel estimation and phase noise compensation in CO-FBMC are different from those of RGI CO-OFDM. In this work, we considered two equalization techniques (including both channel and phase noise estimations) for CO-FBMC, namely the auxiliary pilot (AP) and the coding pilot (CP). For RGI CO-OFDM transmission, the conventional pilot-aided equalization was applied.
© 2017 IEEE
PDF ArticleMore Like This
Qunbi Zhuge, Benoît Châtelain, Chen Chen, and David V. Plant
Th.11.B.5 European Conference and Exposition on Optical Communications (ECOC) 2011
Chuanchuan Yang, Changhong He, and Ziyu Wang
83091N Asia Communications and Photonics Conference and Exhibition (ACP) 2011
Zhaopeng Xu, Zhongwei Tan, and Chuanchuan Yang
Su4C.5 Asia Communications and Photonics Conference (ACP) 2017