www.pudn.com > qpsk-simulink.rar > Fftseq.m

function [M,m,df]=fftseq(m,ts,df)  
%       [M,m,df]=fftseq(m,ts,df) 
%       [M,m,df]=fftseq(m,ts) 
%FFTSEQ     generates M, the FFT of the sequence m. 
%       The sequence is zero padded to meet the required frequency resolution df. 
%       ts is the sampling interval. The output df is the final frequency resolution. 
%       Output m is the zero padded version of input m. M is the FFT. 
fs=1/ts; 
if nargin == 2 
  n1=0; 
else 
  n1=fs/df; 
end 
n2=length(m); 
n=2^(max(nextpow2(n1),nextpow2(n2))); 
M=fft(m,n); 
m=[m,zeros(1,n-n2)]; 
df=fs/n;