光脉冲欠采样宽带数字测频方法的设计与分析  

Design and Analysis of Wideband Digital Frequency Measurement Based on Optical Sub-Sampling

作　　者：彭越[1] 张洪明[1] 姚敏玉[1] 

机构地区：[1]清华大学电子工程系,集成光电子学国家重点联合实验室/信息科学与技术国家实验室(清华大学),北京100084

出　　处：《光电工程》2008年第3期68-72,共5页Opto-Electronic Engineering

基　　金：国家自然科学基金(60477021和60607008)资助项目

摘　　要：为了突破高速电模数转换器采样速率和时延控制精度对测频带宽的限制,文中提出了一种采用光脉冲欠采样的超宽带、高分辨率数字测频方法。利用被动锁模激光器的超短光脉冲,产生间隔可控的多波长光脉冲串,通过电光调制器,对待测信号进行采样,最后通过光探测器阵列转化为电信号进行测频计算。此方法利用光脉冲的采样带宽高、时延控制精确、波分复用技术等特点,结合欠采样的Multiple Signal Classification算法进行宽带频率测量。通过对实际应用条件进行的数值模拟和理论计算表明,该方法可以实现20GHz带宽范围内的高精度多信号频率分辨。In order to break through the limitation of Electronic analog-to-digital converter in speed and time-delay precision, a wideband digital frequency measurement method based on optical sub-sampling is proposed. Taking advantage of ultrashort optical pulse from passive mode-locked fiber laser, multi-wavelength optical pulse duster with controllable time-delay is produced. Traveling through electric-optic modulator, pulse duster samples the signal and is detected by photodiode array, and then we could calculate the frequency spectrum in electric domain. Combined with Multiple Signal Classification algorithm （MUSIC）, the method has advantage of high sampling bandwidth, accurate time-delay and Wavelength Division Multiplex （WDM） technology. According to theoretical research and numerical simulation result, this method is able to get high-resolution multiple frequency measurement with a bandwidth of 20GHz.

关 键 词：数字接收机 数字测频 光采样 MUSIC算法 欠采样 

分 类 号：TN977[电子电信—信号与信息处理]