基于调制宽带转换器的低频射电天文信号采集电路设计及实现  

Design and realization of low frequency radio astronomical signal acquisition circuit based on modulated wideband converter

作　　者：吴海龙[1] 柏正尧[1] 张瑜[1] 何倩 

机构地区：[1]云南大学信息学院,昆明650500

出　　处：《计算机应用》2018年第2期610-614,共5页journal of Computer Applications

基　　金：国家自然科学基金资助项目(U1231122);云南大学第八届研究生科研创新资助项目~~

摘　　要：针对射电天文信号观测中传统的信号采集电路存储数据需较大的存储空间的问题,提出一种基于调制宽带转换器(MWC)的低频射电天文信号采集的硬件电路设计方法。首先,将观测信号与4路伪随机周期信号相乘后分为4路,并将这4路信号分别进行二阶巴特沃兹低通滤波器滤波;然后,对4路滤波后的信号进行采样,数据传输至现场可编程门阵列(FPGA)中进行存储;最后,用正交匹配追踪(OMP)算法进行信号重构。理论分析和实验测试结果表明,重构信号与观测信号的均方误差为1.27×10^(-2),数据存储空间压缩率为20%,该硬件电路设计方法降低了电路设计成本,也释放了存储空间。Aiming at the problem that the traditional signal acquisition circuit needs a larger storage space to store data in the observation of radio astronomical signal, a hardware circuit design method for low frequency radio astronomical signal acquisition based on Modulated Wideband Converter( MWC) was proposed. Firstly, the observed signal was multiplied by four pseudo-random period signals, and then the results were divided into four channels. Secondly, the four-channel signals were filtered by second-order Butterworth low-pass filter repectively. Then, the four-channel filtered signals were sampled and the data were transferred to a Field-Programmable Gate Array( FPGA) for storage. Finally, the signal was reconstructed by Orthogonal Matching Pursuit( OMP) algorithm. The theoretical analysis and experimental results show that the Mean Square Error( MSE) between the reconstructed signal and the observed signal is 1. 27 × 10^(-2), and the compression rate of data storage space is 20%. The proposed hardware circuit design method reduces circuit design costs as well as storage space.

关 键 词：调制宽带转换器 压缩采样 射电天文信号 低通滤波 信号重构 

分 类 号：TN911[电子电信—通信与信息系统]