sdft1.m

数字信号处理实践方法

%
% 4-point DFT (sdft1.m)
% A simple m-file script illustrating direct 4-point DFT computation.
% input data: x(0)=1, x(1)=5, x(2)=4, x(3)=2.
%
N=4;j=sqrt(-1);
x0=1; x1=5; x2=4; x3=2;
X0=x0+x1+x2+x3;
X11=x1*exp(-j*2*pi/N);
X12=x2*exp(-j*2*pi*2/N);
X13=x3*exp(-j*2*pi*3/N);
X1a=x0+X11+X12+X13;
X1=x0+x1*exp(-j*2*pi/N)+x2*exp(-j*2*pi*2/N)+x3*exp(-j*2*pi*3/N);
X2=x0+x1*exp(-j*2*pi*2/N)+x2*exp(-j*2*pi*2*2/N)+x3*exp(-j*2*pi*2*3/N);
X3=x0+x1*exp(-j*2*pi*3/N)+x2*exp(-j*2*pi*3*2/N)+x3*exp(-j*2*pi*3*3/N);
X11
X12
X13
X1a
X0
X1
X2
X3