一种宽带VLBI数字基带转换器设计

摘要

VLBI(very long baseline interferometry) is a radio observation mean which has the highest precision currently.To solve the problem of over-high requirement about processing speed of hardware,a wideband VLBI digital baseband converter based on parallel down-conversion is designed,combining parallel processing with polyphase filtering,which can greatly reduce the requirement of processing speed,relieve the pressure of hardware,and help solving the bottleneck problem of digital signal processing.The simulation results show that this wideband VLBI digital baseband converter successfully realizes functions of down-converting,filtering and decimating of the digital IF signal,at the same time,the data rate is greatly reduced.So it can realize wideband receiving and processing,and also contribute to real-time signal processing.%VLBI(very long baseline interferometry)即甚长基线干涉测量,是目前精度最高的射电观测手段.为了解决对硬件处理速度要求过高的问题,设计了一种基于并行下变频的宽带VLBI数字基带转换器,将并行处理与多相滤波相结合,可大大降低对处理速度的要求,缓解硬件压力,有助于解决数字信号处理的瓶颈问题.仿真结果表明,该宽带VLBI数字基带转换器成功实现了对数字中频信号的下变频、滤波抽取等功能,同时数据率大大降低,可实现宽带接收处理,也有助于信号的实时处理.