基于多项滤波原理的DDC设计及FPGA实现  

Design of Digital Down Conversion Based on Polyphase Structure and Its FPGA Implementation

作　　者：孙娟[1] 韩涛[1] 于巍巍[1] 刘汝猛 

机构地区：[1]中国空间技术研究院西安分院,西安710000

出　　处：《空间电子技术》2014年第2期54-58,共5页Space Electronic Technology

摘　　要：微波遥感数据处理中往往要对接收的回波信号直接进行中频采样,然后利用数字下变频(DDC)技术实现正交解调,这样可以减少系统的复杂性,提高微波遥感数据处理器的数字化程度和性能。文章针对传统DDC方法存在运算数据量大,镜频抑制比小及硬件实现资源消耗大等方面的不足,分析了一种基于多相滤波结构的数字下变频方法,并通过Matlab仿真和FPGA实现验证了该方法的有效性、可行性和实用性。同时,实验结果也表明该方法较之传统的低通滤波法有很大的优越性。In order to reduce system complexity and improve the performance of data processor, the echo data received in microwave remote sensor is always sampled at intermediate frequency. Then Digital Down Converter （DDC） is used to realize quadrature demodulation. In view of the deficiency of the traditional DDC such as greater data stream, smaller image frequency ratio and vaster cost of resources, a new method based on polyphase filter structure is given in this paper. The simulation results by Matlab and FPGA indicate that the proposed DDC method is valid, feasible and practicable. At the same time, the results of the experiment also show its superiority over the traditional DDC method.

关 键 词：微波遥感 中频采样 数字下变频 多项滤波器 

分 类 号：TP312[自动化与计算机技术—计算机软件与理论]