Differential Phase-Based Frequency Offset Estimation for 16-QAM Coherent Optical Systems

作者：Liu Yumin^*; Peng Yunfeng; Zhang Yuhong; Liu Yuhan; Zhang Zhizhong

来源：IEEE Photonics Technology Letters, 2014, 26(24): 2492-2494.

DOI：10.1109/LPT.2014.2359178

• Coherent optical receiver
• frequency offset estimation
• quadrature amplitude modulation
• differential phase

This letter presents a novel differential phase-based frequency offset estimation algorithm for square 16-ary quadrature amplitude modulation coherent optical systems. Different from the existing algorithm using only consecutive Class I symbols (CCIS), all the constellation points (i.e., both Class I and Class II symbols) are used here to estimate frequency offset. By considering the compatibility of symbols in different Class, eighth power operation is implemented to remove the modulated data phase, before which rotating by pi/8 is needed for Class II symbols. Simulation results show that the proposed algorithm leads to 0.7-dB signal-to-noise ratio per symbol improvement at bit-error rate of 10(-3) due to its high estimation accuracy compared with the conventional CCIS scheme.

• 出版日期2014-12-15
• 单位唐山学院