实验演示100 Gbaud Delta-Sigma调制信号O波段传输  

Experimental Demonstration of 100 Gbaud Delta-Sigma Modulation Signal Transmission over O-Band

作　　者：杨雄伟 魏怡 龙健宇 余建军 Yang Xiongwei;Wei Yi;Long Jianyu;Yu Jianjun(Department of Communication Science and Engineering,School of Information Science and Technology,Fudan University,Shanghai 200433,China)

机构地区：[1]复旦大学信息科学与工程学院通信科学与工程系,上海200433

出　　处：《光学学报》2023年第20期67-73,共7页Acta Optica Sinica

基　　金：国家自然科学基金(618350026,1935005)。

摘　　要：为了解决传输高阶正交幅度调制(QAM)信号时的非线性损伤问题,提出了一种基于Delta-Sigma调制(DSM)的高阶QAM传输系统。通过采用1-bit量化的DSM,成功将携带有高阶QAM的离散多音调制(DMT)信号量化编码为开关键控(OOK)信号,实现了高阶QAM信号在O波段强度调制/直接检测(IM/DD)系统中的传输。由于DSM拥有较高的量化信噪比,系统最高支持满足软判决2.4×10-2阈值的4096QAM信号的传输。特别地,通过采用预均衡技术,成功实现了50/100 Gbaud DSM信号分别在O波段的50/15 km的传输。实验演示了高速DSM信号在O波段的传输系统,为高阶QAM信号在IM/DD链路的传输提供了解决方案,同时也为未来基于DSM技术的高速移动前传方案设计提供了参考。Objective To solve the nonlinear impairment during transmitting high-order quadrature amplitude modulation(QAM)signals,we propose a high-order QAM transmission system based on Delta-Sigma modulation(DSM).With the commercialization of 5G networks,the number of mobile internet traffic terminals has surged to increase the demand for fronthaul network transmission rates.At present,the mobile fronthaul network interface common public radio interface(CPRI)usually adopts 15-bits sampling width,which means that at least 15 times of oversampling is required,which results in low spectral efficiency(SE).To this end,researchers proposed a fronthaul network based on DSM technology.Under ten times of oversampling,one-bit quantized DSM can provide a signal-to-noise ratio(SNR)of about 33 dB and support 1024QAM mobile fronthaul.Therefore,facing ever-increasing traffic demands,we study the transmission performance of broadband DSM signals to provide certain references for the future design of high-speed fronthaul networks based on DSM technology.Methods To study the transmission performance of broadband DSM signals,we carry out the transmission experiment of 100 Gbaud DSM signal.For the power fading caused by chromatic dispersion that often occurs in intensity modulation/direct detection(IM/DD)systems,we have chosen the O-band transmission.For the insufficient bandwidth for the transmission system,we employ pre-equalization technology to address the high-frequency fading caused by narrow-band channels.We adopt the on-off-keying(OOK)signal as the training sequence and carry out 100 Gbaud optical back-to-back(BTB)transmission.Then,the frequency domain corresponding to the tap coefficient in the steady state of the constant modulus algorithm(CMA)in the digital signal processing(DSP)algorithm is taken as the inverse response of the channel.Afterward,the finite impulse response(FIR)is generated according to the tap coefficients of CMA.Finally,the generated FIR filter is utilized to filter the transmission signal after two-up-sampling t

关 键 词：光通信 Delta-Sigma调制 移动前传 强度调制/直接检测 

分 类 号：TN929.11[电子电信—通信与信息系统]