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

摘要:

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5.4GHz的中心频率和4.3GHz的10dB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5.5dBm,有效降低了误码率,提升了光载超宽带系统的传输性能。

Abstract:

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.