几个数字信号处理算法程序

【 tulaoshi.com - C语言心得技巧 】

几个数字信号处理算法程序

作者：liu_sir

摘要

在学习数字信号处理算法程序中用VC编写的几个通用算法程序。

关键词 离散卷积 FIR

在学习信号处理的过程中,看到书上的大部分算法都是用Fortan或者Basic实现,于是自己试验着用VC实现了一下。

1、卷积计算

离散卷积公式的算法实现

1.1 主程序代码(省略了部分不关键代码)

void CInterVolveDlg::CalTheNumByArray() {this-UpdateData(TRUE);FFuncsfuncs[2] = {funch1,funch2}; intn = this-m_ValueN; double*x = new double[2*(n+1)];//x(n) double*y = new double[2*(n+1)];//y(n) double*h = new double[2*(n+1)];//h(n) //1.init    x(n),h(n),y(n) CButton*pbtn = (CButton*) this-GetDlgItem(IDC_RADIO1); intnChoseItem = 0;//函数选择 if(pbtn-GetCheck()){nChoseItem= 0; }else{nChoseItem= 1; }for(inti= 0;i<2*(n+1);i++){if(i< n+1){x[i] = 1;h[i] = funcs[nChoseItem](i);}else{x[i] = 0;h[i] = 0;}}//2.y(i)=SUM(x(m)*h(i-m))  m=0..ifor(i=0;i<2*(n+1);i++){y[i] = Calcy(x,h,i);} //显示结果delete[] x;delete[] y;delete[] h;}

typedef double (* FFuncs)(int); //h1(x) doublefunch1(intn) { doublefbase= (double)4/(double)5; double fr= std::pow(fbase, n); return fr;} //h2(x)doublefunch2(intn) { doublefpi= 3.1415927; return 0.5*sin((double)0.5*n);} //y(n)//y(n)=sum(x(m)*y(n-m))m=0..n doubleCalcy(double x[],double h[],int n) {doubleyvalue =  0; for(intm= 0;m<=n;m++){yvalue += x[m]*h[n-m];}return yvalue;}

程序界面,具体实现见注释及代码:

图2 DFT与FFT实现界面

void CFFTConversionDlg::OnBnClickedBtncal() {this-UpdateData(TRUE);intnN = this-m_NumN; floatfF = this-m_NumF; floatfT = this-m_NumT; boolbIsTimesof2 = false; for(int i= 0;i<100;i++){        if(nN==(2 < < i)){bIsTimesof2 = true;break;}}if(!bIsTimesof2){AfxMessageBox("N请输入一个以2为底的幂级数!");this-GetDlgItem(IDC_EDTN)-SetFocus();return;}COMP* x = new COMP[nN];//x(n)COMP* X = new COMP[nN];//X(k) initX(nN,x,fF,fT);CButton* pRadio = (CButton*)this-GetDlgItem(IDC_RADIODFT);if(pRadio-GetCheck()){DFT(nN,x,X);}else{FFT(nN,x,X);}char buffer[256];COMP source = X[nN-1];sprintf(buffer,"%f+%fi",source.real(),source.imag());CWnd* pwnd = this-GetDlgItem(IDC_EDTRET);pwnd-SetWindowText(buffer);CListCtrl* pList=(CListCtrl*) this-GetDlgItem(IDC_LIST1);CListOper oper;oper.FillList(*pList,nN,x,X);delete[] x; delete[] X;}

/******************************************* Name     :DFT*   Function :Disperse Fuliye Transformation*   Params   :N -- Total count of sampling points*             X -- Input sequence*   Return   :XN(k)=sum[x(n)*Pow(e,j2*Pi/N)] *                   k,n:0..N-1*******************************************/void DFT(int N,COMP x[],COMP XK[]){double C = (2*pi)/N;COMP t(0,0),ret(0,0);for(int k=0;k < N;k++){ret = COMP(0,0);for(int i=0;i< N;i++){t = COMP(cos(C*k*i),-sin(C*k*i));ret += x[i]*t;}XK[k] = ret;}}/******************************************* Name     :FFT*   Function :Fast Fuliye Transformation*   Params   :N -- Total count of sampling points*             X -- Input sequence*   Return   :XN(k)=sum[x(n)*Pow(e,j2*Pi/N)] *                   k,n:0..N-1*******************************************/void FFT(int N,COMP X[],COMP XK[]){int j=0;COMP U=0,W=0;COMP* A = XK;//Adjust sequencef