DFT.zip_DFT_made

// 디지털 통신 시스템 설계/실습 3주차 - DFT & IDFT #include <iostream> #include <cstdlib> #include <cmath> #include <fstream> using namespace std; using std::ofstream; void main() { const int n = 2000+1; // number of size const int nn = 2000; const double dt = 0.001; // step size const double Ts = 0.008; // sampling const double N = nn+1; // number of sampled size; const double pi = 3.141592; double x[n] = {0}; double xs[nn] = {0}; // size = N double Xkc[nn] = {0}; // size = N double Xks[nn] = {0}; // size = N double xnc[nn] = {0}; // size = N double xns[nn] = {0}; // size = N double t[n] = {0}; double Xkc1[nn] = {0}; // lobe 1 double Xks1[nn] = {0}; ofstream C; C.open("original.txt"); for (int i=0; i<n; i++) { if(i==0) t[i] = -1; else t[i] = t[i-1]+dt; } for (i=0; i<n; i++) { if((t[i]>=-0.01) && (t[i] <=0.01)) x[i] = 1; C << x[i] << endl; } C.close(); /*ofstream D; D.open("sampled.txt"); for (int j=0; j<N; j++) { if(j==0) t[j] = 0; else t[j] = t[j-1]+Ts; xs[j] = sin(200*t[j]); D<< xs[j] << endl; } D.close(); */ // DFT ofstream A; ofstream B; A.open("DFTi.txt"); B.open("DFTq.txt"); Xks[0] = 0; for (int k=0; k<N; k++) { for (int ii=0; ii<N; ii++) { Xkc[k] = Xkc[k]+x[ii]*cos((2*pi/N)*k*ii); Xks[k] = Xks[k]+x[ii]*sin((2*pi/N)*k*ii); } A << Xkc[k] << endl; B << Xks[k] << endl; } A.close(); B.close(); // IDFT ofstream E; ofstream F; E.open("IDFTi.txt"); F.open("IDFTq.txt"); for (int jj=0; jj<N; jj++) { for (int kk=0; kk<N; kk++) { xnc[jj] = xnc[jj] + 1/N*(Xkc[kk]*cos((2*pi/N)*kk*jj)); xns[jj] = xns[jj] + 1/N*(Xks[kk]*sin((2*pi/N)*kk*jj)); } E << xnc[jj] << endl; F << xns[jj] << endl; } E.close(); F.close(); }