DFT测频的加窗插值算法与实现  

Algorithm and Implementation of Windowed Interpolation for DFT Measuring Frequency

作　　者：谢锘[1,2] 王晓君[2] 葛建华[1] 

机构地区：[1]西安电子科技大学ISN国家重点实验室,西安710071 [2]河北科技大学信息科学与工程学院,石家庄050018

出　　处：《电子科技大学学报》2011年第2期192-196,共5页Journal of University of Electronic Science and Technology of China

基　　金：国家863计划(F0906017)

摘　　要：分析DFT频谱中栅栏效应的形成原因,推导出DFT频谱的幅度比值校正算法,在此基础上,系统地推导不同加窗函数下的插值校正公式以提高DFT测频精度,重点探讨插值算法的工程实现方法,提出一种适于FPGA实现的基于区间搜索的频率偏差估计算法,以避免复杂的除法运算。通过对不同信噪比、不同频率偏差下的校正结果进行仿真分析,发现该算法完全满足工程实际需要。The gird effect fence in DFT spectrum is deeply analyzed. The correction algorithm of amplitude ratio is deduced and the interpolating correction equations with different windowed-functions are derived on the basis of classic Rife algorithm to improve the measuring-frequency accuracy. A method for engineering implementation based on field programmable gate array （FPGA） is also discussed. A novel estimate algorithm of frequency offset for FPGA is provided based on interval search to avoid complex division operation. The simulation result shows that estimate algorithm of frequency offset based on interval search meets well the engineering requirements.

关 键 词：离散傅里叶变换 工程实现 插值 频谱校正 

分 类 号：TP971.1[自动化与计算机技术]