摘要
A spectrum efficient OFDM scheme named Time Domain Synchronous-OFDM(TDS-OFDM)is introduced into coherent optical transmission system,in which the pseudo noise(PN)sequence is exploited as guard interval to realize frame synchronization,compensate the carrier frequency offset(CFO),and estimate and equalize channel simultaneously.Since there is no pilot signals or training symbols in TDS-OFDM,the proposed scheme can achieve higher spectral efficiency(SE)above 10%improvement comparing with CPOFDM.The proposed method is implemented and verified in a 28GBaud QPSK OFDM system and a 28GBaud 16QAM OFDM system.It is demonstrated that the proposed scheme shows high CFO estimation accuracy and synchronous accuracy.Under CFO and linewidth of laser source set as 100MHz and 100kHz respectively,BER of QPSK OFDM system is below 3.8e-3 at the optical signal-to-noise ratio(OSNR)of 13dB,and BER of 16QAM OFDM system is below 3.8e-3 at the OSNR of 20dB.
A spectrum efficient OFDM scheme named Time Domain Synchronous-OFDM(TDS-OFDM) is introduced into coherent optical transmission system, in which the pseudo noise(PN) sequence is exploited as guard interval to realize frame synchronization, compensate the carrier frequency offset(CFO),and estimate and equalize channel simultaneously.Since there is no pilot signals or training symbols in TDS-OFDM, the proposed scheme can achieve higher spectral efficiency(SE)above 10% improvement comparing with CPOFDM.The proposed method is implemented and verified in a 28 GBaud QPSK OFDM system and a 28 GBaud 16 QAM OFDM system.It is demonstrated that the proposed scheme shows high CFO estimation accuracy and synchronous accuracy. Under CFO and linewidth of laser source set as 100 MHz and 100 kHz respectively, BER of QPSK OFDM system is below 3.8 e-3 at the optical signal-to-noise ratio(OSNR) of 13 dB, and BER of 16 QAM OFDM system is below 3.8 e-3 at the OSNR of20 dB.
基金
supported by the State Grid Corporation of China (No. 5101/2017-3205A)
the Open Fund of the Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications (Jinan University)
the National Natural Science Foundation of China (NSFC) (61571057, 61501214, 61527820, 61575082)
