Li Fan, Zhang Junwen, Cao Zizheng, Yu Jianjun, Li Xinying, Chen Lin, Xia Yan, Chen Yufei
Opt Express. 2013 Dec 16;21(25):30999-1005. doi: 10.1364/OE.21.030999.
Quad-Carrier Quadrature Phase Shift Keyed orthogonal frequency division multiplexing (QPSK-OFDM) signal transmission and reception is successfully demonstrated with blind equalization like a 25-ary quadrature amplitude modulation (25-QAM) signal with cascaded multi-modulus algorithm (CMMA) equalization. The phase recovery can be realized with simple Viterbi algorithm and the frequency offset estimation (FOE) should be done with 25-QAM signal before 4-point fast Fourier transform (FFT). 48-Gbit/s Quad-Carrier QPSK-OFDM signal is successfully transmitted over 80-km SMF-28 without penalty.
通过使用类似于具有级联多模算法（CMMA）均衡的25进制正交幅度调制（25-QAM）信号的盲均衡，成功演示了四载波正交相移键控正交频分复用（QPSK-OFDM）信号的发送和接收。相位恢复可以通过简单的维特比算法实现，并且在4点快速傅里叶变换（FFT）之前，频率偏移估计（FOE）应该使用25-QAM信号来完成。48-Gbit/s的四载波QPSK-OFDM信号在80公里的SMF-28光纤上成功传输且无损耗。
