基于微波光子学的光载超宽带信号产生和传输技术

Microwave Photonics-based Generation and Transmission Technology of Ultra-broadband Signal over Fiber

光载超宽带技术因兼具超宽带信号大带宽、传输速率高等优点和光纤传输的远距离传输、损耗小等优势而在近年来备受关注。文章提出一种基于微波光子技术产生超宽带(UWB)信号的系统,该方案基于非线性PM-IM转换,产生一阶超宽带信号,然后又用平衡光电探测器(BPD)和光延迟线构建延迟线滤波器对其进行一阶差分,产生了符合美国联邦通信委员会(FCC)掩膜要求的二阶超宽带信号。系统最终产生的二阶超宽带信号的频谱具有大约5.4 GHz的中心频率和4.3 GHz的10 dB带宽。另外,还提出了一种基于直接序列-二进制相移键控调制(DS-BPSK),并使用卷积编码进行信道编码,然后使用啁啾布拉格光栅对信号进行色散补偿的信号处理技术。通过Opti-system软件进行仿真验证,在前向纠错门限为3.8×10^(-3)时,接收机灵敏度提升了约5.5 dBm,有效降低了误码率,提升了光载超宽带系统的传输性能。

Ultra-broadband(UWB)over fiber technology has attracted much attention in recent years because of the advantages of large bandwidth and high transmission rate of UWB signals and the advantages of long-distance transmission and low loss of optical fiber transmission.A system for generating UWB signal based on microwave photonic technology was proposed,which was based on non-linear PM-IM conversion to generate monocycle signal.Then the first-order difference was performed on the signal by using a balanced photodetector(BPD)and an optical delay line to build a delay line filter,producing a doublet signal that met FCC mask requirements.The doublet UWB signal has a center frequency of 5.4GHz and a 10dB bandwidth of 4.3GHz.A signal processing technique based on DS-BPSK was also proposed,with channel coding using convolutional coding,followed by chirped Bragg gratings for dispersion compensation of the signal.Through the simulation by Opti-system software,when the FEC threshold is 3.8×10^(-3),the sensitivity of the receiver is increased by 5.5dBm,effectively reducing the bit error rate and improving the transmission performance of the system of ultra-wideband over fiber.