FFT算法(查表法)(共8页)

1、ARM或单片机用的FFT算法，用于信号处理。经过愚昧的本人优化，提高了计算效率（在aduc7026 41MHz FFT256点 环境下 运算时间为0.06s左右）PS：以下有两部分（fft.h和fft.c）【复制以下内容改名为fft.h】#ifndef _FFT_H_#define _FFT_H_#include#ifdef FFT_GLOBALS#define FFT_EXT#else#define FFT_EXT extern#endif#define PI 3.1415926#define FFT_POINT 8 /设置点数(此值变，下面的也要变)(011)#define SAMPLE_

2、NUM 256/可设256或512两种数/countn /count=1,2,4,8,16,32,64,128,256,512,1024,2048FFT_EXT float dataRSAMPLE_NUM;FFT_EXT float dataISAMPLE_NUM;FFT_EXT void SetData(float data,unsigned int i); /采集数据到第i个点(0SAMPLE_NUM)FFT_EXT void FFT(void);/采样来的数据放在dataR 数组中/*FFT结果数值处理*/计算和返回峰(模)值，k表示第几个值（0SAMPLE_NUM-1）,type为0返

3、回峰值，1返回模值，2返回有效值FFT_EXT float GetPeak(unsigned int k,unsigned int type); /FFT_EXTfloat GetPhase(unsigned int k,unsigned int type); /计算和返回相位,k同上 /type为0返回角度，1返回弧度/speed为采样速率，返回第k(0SAMPLE_NUM)个点代表的频率FFT_EXT float GetStepF(float speed,unsigned int k); FFT_EXT float GetPower1(unsigned int k); /返回功率谱的第k点

4、FFT_EXT float GetPower2(unsigned int k,float total); / 返回k点所占的功率百分比(单位是%) total为总功率 FFT_EXT float GetTotalPower(void); /计算功率谱总和 FFT_EXT float GetTHD(void); /计算失真度#endif/【复制以下内容改名为fft.c】/查表式FFT算法#define FFT_GLOBALS#include fft.h#if SAMPLE_NUM=256 const float sin_tab256=0.000000,0.024541,0.049068,0.07

5、3565,0.098017,0.122411,0.146730,0.170962,0.195090,0.219101,0.242980,0.266713,0.290285,0.313682,0.336890,0.359895,0.382683,0.405241,0.427555,0.449611,0.471397,0.492898,0.514103,0.534998,0.555570,0.575808,0.595699,0.615232,0.634393,0.653173,0.671559,0.689541,0.707107,0.724247,0.740951,0.757209,0.77301

6、0,0.788346,0.803208,0.817585,0.831470,0.844854,0.857729,0.870087,0.881921,0.893224,0.903989,0.914210,0.923880,0.932993,0.941544,0.949528,0.956940,0.963776,0.970031,0.975702,0.980785,0.985278,0.989177,0.992480,0.995185,0.997290,0.998795,0.999699,1.000000,0.999699,0.998795,0.997290,0.995185,0.992480,0

7、.989177,0.985278,0.980785,0.975702,0.970031,0.963776,0.956940,0.949528,0.941544,0.932993,0.923880,0.914210,0.903989,0.893224,0.881921,0.870087,0.857729,0.844854,0.831470,0.817585,0.803208,0.788346,0.773010,0.757209,0.740951,0.724247,0.707107,0.689541,0.671559,0.653173,0.634393,0.615232,0.595699,0.57

8、5808,0.555570,0.534998,0.514103,0.492898,0.471397,0.449611,0.427555,0.405241,0.382683,0.359895,0.336890,0.313682,0.290285,0.266713,0.242980,0.219101,0.195090,0.170962,0.146730,0.122411,0.098017,0.073565,0.049068,0.024541,0.000000,-0.024541,-0.049068,-0.073565,-0.098017,-0.122411,-0.146730,-0.170962,

9、-0.195090,-0.219101,-0.242980,-0.266713,-0.290285,-0.313682,-0.336890,-0.359895,-0.382683,-0.405241,-0.427555,-0.449611,-0.471397,-0.492898,-0.514103,-0.534998,-0.555570,-0.575808,-0.595699,-0.615232,-0.634393,-0.653173,-0.671559,-0.689541,-0.707107,-0.724247,-0.740951,-0.757209,-0.773010,-0.788346,

10、-0.803208,-0.817585,-0.831470,-0.844854,-0.857729,-0.870087,-0.881921,-0.893224,-0.903989,-0.914210,-0.923880,-0.932993,-0.941544,-0.949528,-0.956940,-0.963776,-0.970031,-0.975702,-0.980785,-0.985278,-0.989177,-0.992480,-0.995185,-0.997290,-0.998795,-0.999699,-1.000000,-0.999699,-0.998795,-0.997290,

11、-0.995185,-0.992480,-0.989177,-0.985278,-0.980785,-0.975702,-0.970031,-0.963776,-0.956940,-0.949528,-0.941544,-0.932993,-0.923880,-0.914210,-0.903989,-0.893224,-0.881921,-0.870087,-0.857729,-0.844854,-0.831470,-0.817585,-0.803208,-0.788346,-0.773010,-0.757209,-0.740951,-0.724247,-0.707107,-0.689541,

12、-0.671559,-0.653173,-0.634393,-0.615232,-0.595699,-0.575808,-0.555570,-0.534998,-0.514103,-0.492898,-0.471397,-0.449611,-0.427555,-0.405241,-0.382683,-0.359895,-0.336890,-0.313682,-0.290285,-0.266713,-0.242980,-0.219101,-0.195090,-0.170962,-0.146730,-0.122411,-0.098017,-0.073565,-0.049068,-0.024541;

13、#endif#if SAMPLE_NUM=512const float sin_tab512=0.000000,0.012272,0.024541,0.036807,0.049068,0.061321,0.073565,0.085797,0.098017,0.110222,0.122411,0.134581,0.146730,0.158858,0.170962,0.183040,0.195090,0.207111,0.219101,0.231058,0.242980,0.254866,0.266713,0.278520,0.290285,0.302006,0.313682,0.325310,0

14、.336890,0.348419,0.359895,0.371317,0.382683,0.393992,0.405241,0.416430,0.427555,0.438616,0.449611,0.460539,0.471397,0.482184,0.492898,0.503538,0.514103,0.524590,0.534998,0.545325,0.555570,0.565732,0.575808,0.585798,0.595699,0.605511,0.615232,0.624859,0.634393,0.643832,0.653173,0.662416,0.671559,0.68

15、0601,0.689541,0.698376,0.707107,0.715731,0.724247,0.732654,0.740951,0.749136,0.757209,0.765167,0.773010,0.780737,0.788346,0.795837,0.803208,0.810457,0.817585,0.824589,0.831470,0.838225,0.844854,0.851355,0.857729,0.863973,0.870087,0.876070,0.881921,0.887640,0.893224,0.898674,0.903989,0.909168,0.91421

16、0,0.919114,0.923880,0.928506,0.932993,0.937339,0.941544,0.945607,0.949528,0.953306,0.956940,0.960431,0.963776,0.966976,0.970031,0.972940,0.975702,0.978317,0.980785,0.983105,0.985278,0.987301,0.989177,0.990903,0.992480,0.993907,0.995185,0.996313,0.997290,0.998118,0.998795,0.999322,0.999699,0.999925,1

17、.000000,0.999925,0.999699,0.999322,0.998795,0.998118,0.997290,0.996313,0.995185,0.993907,0.992480,0.990903,0.989177,0.987301,0.985278,0.983105,0.980785,0.978317,0.975702,0.972940,0.970031,0.966976,0.963776,0.960431,0.956940,0.953306,0.949528,0.945607,0.941544,0.937339,0.932993,0.928506,0.923880,0.91

18、9114,0.914210,0.909168,0.903989,0.898674,0.893224,0.887640,0.881921,0.876070,0.870087,0.863973,0.857729,0.851355,0.844854,0.838225,0.831470,0.824589,0.817585,0.810457,0.803208,0.795837,0.788346,0.780737,0.773010,0.765167,0.757209,0.749136,0.740951,0.732654,0.724247,0.715731,0.707107,0.698376,0.68954

19、1,0.680601,0.671559,0.662416,0.653173,0.643832,0.634393,0.624859,0.615232,0.605511,0.595699,0.585798,0.575808,0.565732,0.555570,0.545325,0.534998,0.524590,0.514103,0.503538,0.492898,0.482184,0.471397,0.460539,0.449611,0.438616,0.427555,0.416430,0.405241,0.393992,0.382683,0.371317,0.359895,0.348419,0

20、.336890,0.325310,0.313682,0.302006,0.290285,0.278520,0.266713,0.254866,0.242980,0.231058,0.219101,0.207111,0.195090,0.183040,0.170962,0.158858,0.146730,0.134581,0.122411,0.110222,0.098017,0.085797,0.073565,0.061321,0.049068,0.036807,0.024541,0.012272,0.000000,-0.012272,-0.024541,-0.036807,-0.049068,

21、-0.061321,-0.073565,-0.085797,-0.098017,-0.110222,-0.122411,-0.134581,-0.146730,-0.158858,-0.170962,-0.183040,-0.195090,-0.207111,-0.219101,-0.231058,-0.242980,-0.254866,-0.266713,-0.278520,-0.290285,-0.302006,-0.313682,-0.325310,-0.336890,-0.348419,-0.359895,-0.371317,-0.382683,-0.393992,-0.405241,

22、-0.416430,-0.427555,-0.438616,-0.449611,-0.460539,-0.471397,-0.482184,-0.492898,-0.503538,-0.514103,-0.524590,-0.534998,-0.545325,-0.555570,-0.565732,-0.575808,-0.585798,-0.595699,-0.605511,-0.615232,-0.624859,-0.634393,-0.643832,-0.653173,-0.662416,-0.671559,-0.680601,-0.689541,-0.698376,-0.707107,

23、-0.715731,-0.724247,-0.732654,-0.740951,-0.749136,-0.757209,-0.765167,-0.773010,-0.780737,-0.788346,-0.795837,-0.803208,-0.810457,-0.817585,-0.824589,-0.831470,-0.838225,-0.844854,-0.851355,-0.857729,-0.863973,-0.870087,-0.876070,-0.881921,-0.887640,-0.893224,-0.898674,-0.903989,-0.909168,-0.914210,

24、-0.919114,-0.923880,-0.928506,-0.932993,-0.937339,-0.941544,-0.945607,-0.949528,-0.953306,-0.956940,-0.960431,-0.963776,-0.966976,-0.970031,-0.972940,-0.975702,-0.978317,-0.980785,-0.983105,-0.985278,-0.987301,-0.989177,-0.990903,-0.992480,-0.993907,-0.995185,-0.996313,-0.997290,-0.998118,-0.998795,

25、-0.999322,-0.999699,-0.999925,-1.000000,-0.999925,-0.999699,-0.999322,-0.998795,-0.998118,-0.997290,-0.996313,-0.995185,-0.993907,-0.992480,-0.990903,-0.989177,-0.987301,-0.985278,-0.983105,-0.980785,-0.978317,-0.975702,-0.972940,-0.970031,-0.966976,-0.963776,-0.960431,-0.956940,-0.953306,-0.949528,

26、-0.945607,-0.941544,-0.937339,-0.932993,-0.928506,-0.923880,-0.919114,-0.914210,-0.909168,-0.903989,-0.898674,-0.893224,-0.887640,-0.881921,-0.876070,-0.870087,-0.863973,-0.857729,-0.851355,-0.844854,-0.838225,-0.831470,-0.824589,-0.817585,-0.810457,-0.803208,-0.795837,-0.788346,-0.780737,-0.773010,

27、-0.765167,-0.757209,-0.749136,-0.740951,-0.732654,-0.724247,-0.715731,-0.707107,-0.698376,-0.689541,-0.680601,-0.671559,-0.662416,-0.653173,-0.643832,-0.634393,-0.624859,-0.615232,-0.605511,-0.595699,-0.585798,-0.575808,-0.565732,-0.555570,-0.545325,-0.534998,-0.524590,-0.514103,-0.503538,-0.492898,

28、-0.482184,-0.471397,-0.460539,-0.449611,-0.438616,-0.427555,-0.416430,-0.405241,-0.393992,-0.382683,-0.371317,-0.359895,-0.348419,-0.336890,-0.325310,-0.313682,-0.302006,-0.290285,-0.278520,-0.266713,-0.254866,-0.242980,-0.231058,-0.219101,-0.207111,-0.195090,-0.183040,-0.170962,-0.158858,-0.146730,

29、-0.134581,-0.122411,-0.110222,-0.098017,-0.085797,-0.073565,-0.061321,-0.049068,-0.036807,-0.024541,-0.012272;#endifvoid SetData(float data,unsigned int i) dataRi=data;/* 采样来的数据放在dataR 数组中，运算前dataI 数组初始化为0 */void FFT(void)const int count=1,2,4,8,16,32,64,128,256,512,1024,2048;int i,xx,n;int L,j,k,b;

30、float TR,TI,temp,Tsin,Tcos;/,p;long m;int x11=0;n=FFT_POINT; /* following code invert sequence */for(i=0;icountn;i+) xx=0;for(j=0;jn;j+) xj=0;for(j=0;jn;j+) xj=(i/countj)&0x01;for(j=0;jn;j+) xx=xx+xj*countn-j-1;dataIxx=dataRi;for(i=0;icountn;i+) dataRi=dataIi;dataIi=0; /* following code FFT */for(L=

31、1;L=n;L+) /* for(1) */b=1; / i=L-1;b=(L-1); /整型2的n次方简化运算(加快计算速度)m=SAMPLE_NUM/countL;for(j=0;j=b-1;j+) /* for (2) */ Tsin=sin_tab(m*j)%SAMPLE_NUM;Tcos=sin_tab(m*j+SAMPLE_NUM/4)%SAMPLE_NUM; for(k=j;kcountn;k=k+2*b) /* for (3) */ TR=dataRk; TI=dataIk; temp=dataRk+b; dataRk = dataRk+dataRk+b*Tcos+dataIk+b*Tsin; dataIk = dataIk-dataRk+b*Tsin+dataIk+b*Tcos; dataRk+b = TR-dataRk+b*Tcos-dataIk+b*Tsin; dataIk+b = TI+temp*Tsin-dataIk+b*Tcos; /* END for (3) */ /* END for (2) */ /* END for (1) */*FFT数值计算处