FFT插值算法程序.doc

#include?stdafx.h? ?? #include?Fft.h? ?? #include?math.h? ?? ??? const?double?MOD_MAX????=?65535.0;??? const?double?DISP_MAX???=?1.0/255.0;??? extern??FILE?*fp;??? ??? ??????? ??? ??? ??? //FFT运算必须参数? ?? int?????fft_point,fft_order,fft_divide,fft_window,fft_scale;??? bool????fft_cover;??? float???filter[7];//FIR滤波参数? ?? ??? extern?FILE?*fpIandQ;??? extern?bool?m_bIqWrite;??? double?prFilter[256],piFilter[256];??? ??? ??? /**************************************************************************************?? ????????????????????????0?RectangleWindow矩形窗?????? ????FFT变换结果为对称型，矩形窗是使信号突然截断，旁瓣会很大，且衰减较慢，旁瓣的第一个负?? ????峰值为主瓣的21％，第一个正峰值为主瓣的12.6％，第二个负峰值为主瓣的9％，效果一般，泄?? ????漏较大。?? **************************************************************************************/??? double??WINAPI?RectangleWindow(int?t)??? {??? ????double??wt;??? ????wt=1.0;??? ????return?wt;??? }??? ??? /**************************************************************************************?? ????????????????????????1?TriangleWindow三角窗,也称费杰（Fejer）窗，Bartlett?? **************************************************************************************/??? double?WINAPI?TriangleWindow(int?t)??? {??? ??? ????double??wt;??? ????wt=1-t/fft_point;??? ????return?wt;??? }??? ??? /**************************************************************************************?? ????????????????????????2?HanningWindwo汉宁窗，即升余弦窗?? **************************************************************************************/??? double?WINAPI?HanningWindow(int?t)??? {??? ????double?wt;??? ????wt=(1-cos(2*PI*t/fft_point))/2;??? ????return?wt;??? }??? ??? /**************************************************************************************?? ????????????????????????3?HammingWindow海明窗，即改进的升余弦窗?? **************************************************************************************/??? double?WINAPI?HammingWindow(int?t)??? {??? ????double?wt;??? ????wt=0.54-0.46*cos(2*PI*t/fft_point);??? ????return?wt;??? }??? ??? /*****************************