酷跑游戏道具商城:几个数字信号处理算法程序

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

图1 卷积计算界面

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 sequencefor(int i=0;i< N;i++){if(i==0){A[0] = X[0];}else{j=GetInverse(N,j);A[i] = X[j];}}//确定级别数for(int M=0;M< N;M++){if((1<< M)==N)break;}for(int L=1;L<=M;L++)//1-M级依次确定{int LE = (int)pow(2,L);//间隔int LE1 = LE/2;//W级数,如W0,W1,W2...W=COMP(cos(pi/LE1),-sin(pi/LE1));U=COMP(1,0);for(j=0;j< LE1;j++)//{i=j;while(i< N){int IP = i+LE1;COMP T=A[IP]*U;A[IP]=A[i]-T;//蝶形计算A[i]=A[i]+T;i+=LE;}U=U*W;//不同的W次幂}}}void initX(int N,COMP x[],float F,float T){ for(int i=0;i< N;i++){x[i] = COMP(cos(2*pi*F*T*i),0);}}

3.2 子函数代码实现

/*********************************************************************   Name    : FuncHd*Function: Hd()--Required frequency response function***********************************************************************/COMP FuncHd(double LowLimit,double UpperLimit,COMP x){if(x.real()>UpperLimit||x.real() < LowLimit)return 0;elsereturn 1;}void FIR(double LowLimit,double UpperLimit,int N,COMP Hn[]){int M = 2*N;for(int i=0;i < N;i++){Hn[i] = COMP(0,0);for(int k=0;k < M;k++){COMP C = COMP(cos(2*pi*i*k/(double)M),sin(2*pi*i*k/(double)M));Hn[i] += C*FuncHd(LowLimit,UpperLimit,COMP(cos(2*pi*k/(double)M),sin(2*pi*k/(double)M)));}Hn[i] = Hn[i]*COMP(1/(double)M,0);}}

　　基本算法参考《数字信号处理基础及试验》--王树勋主编。虽然现在DSP算法都有很好C语言实现。但是能够通过自己动手编写代码加深对基础知识的掌握，对自己进行数据采集器件的控制还是有很多益处的。