Constant OverLap-Add

短时傅立叶变换

 

• w(n) - Window function, length M.
• R - Hop size

 

为使

窗函数w(n)满足Constant OverLap-Add, COLA。

 

测试代码：(Scilab 5.0.2)

//

// COLA

//

M=32;    // Window length

R=M/2;  // Hop size

N=3*M;  // Overlap-Add span

wbar=window('hm',M+1);

w=wbar(1:M);    // Window function with endpoint removed, similar to Matlab function hamming(M, 'periodic')

s=zeros(1,N);

wzp=zeros(1,N);

 

f=scf(0);

for so=0:R:N-M

  ndx=so+1:so+M;

  s(ndx)=s(ndx)+w;

  wzp(ndx)=w;

  plot2d(0:N-1,wzp, style=color('red'));

end

scf(f);

plot2d(0:N-1,s, style=color('blue'));

set(f,'Figure_name','COLA');

a=gca();

a.grid=[1,1]*color('gray');