FIR源程序各位帮忙解读一下吧

只看该作者 · 2013-5-27 09:13

#include "DSP28_Device.h"    // DSP281x Headerfile Include File
//#include "DSP281x_Examples.h" // DSP281x Examples Include File
//#include "f2812a.h"
#include"math.h"

#define FIRNUMBER 25
#define SIGNAL1F 1000
#define SIGNAL2F 4500
#define SAMPLEF  10000
#define PI 3.1415926
#define Pi 3.1415926
float InputWave();
float FIR();

//冲激响应系数

float fHn[FIRNUMBER]={ 0.0,0.0,0.001,-0.002,-0.002,0.01,-0.009,
                     -0.018,0.049,-0.02,0.11,0.28,0.64,0.28,
                     -0.11,-0.02,0.049,-0.018,-0.009,0.01,
                     -0.002,-0.002,0.001,0.0,0.0
                  };
float fXn[FIRNUMBER]={ 0.0 };
float fInput,fOutput;
float fSignal1,fSignal2;
float fStepSignal1,fStepSignal2;
float f2PI;
int i;
float fIn[256],fOut[256],H[102];
int nIn,nOut;
main(void)
{
InitSysCtrl();
nIn=0; nOut=0;
f2PI=2*PI;
fSignal1=0.0;
fSignal2=PI*0.1;
fStepSignal1=2*PI/30;
fStepSignal2=2*PI*1.4;
  while ( 1 )
{
  fInput=InputWave();
  fIn[nIn]=fInput;
  nIn++; nIn%=256;
  fOutput=FIR();
  fOut[nOut]=fOutput;
  nOut++;
  if ( nOut>=256 )
  {
nOut=0;  /* 请在此句上设置软件断点 */
  }
}
}

float InputWave()
{
for ( i=FIRNUMBER-1;i>0;i-- )
  fXn=fXn[i-1];
// fXn[0]=sin(fSignal1)+cos(fSignal2)/6.0;  //此时为混合信号（sin 为低频信号，cos为高频信号）
// fXn[0]=cos(fSignal2)/6.0; //此时为cos 高频信号
fXn[0]=sin(fSignal1); //此时为sin 低频信号
fSignal1+=fStepSignal1;
if ( fSignal1>=f2PI ) fSignal1-=f2PI;
fSignal2+=fStepSignal2;
if ( fSignal2>=f2PI ) fSignal2-=f2PI;
return(fXn[0]);
}

float FIR()
{
float fSum;
fSum=0;
for ( i=0;i<FIRNUMBER;i++ )
{
  fSum+=(fXn*fHn);
}
return(fSum);
}

只看该作者 · 2013-5-27 09:14

这是低通滤波程序，我把它放在ccs里面运行了，结果正确，可是还是有很多问题没有解决掉，请各位高手不吝赐教！！

FIR源程序各位帮忙解读一下吧

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