我的分数阶傅里叶变换如下，怎么将它和短时傅里叶变换结合起来，变成短时分数阶傅里叶变换，有没有大佬指点一下下！！！

frft：

function Faf = frft(f, a)

% The fast Fractional Fourier Transform

% input: f = samples of the signal

%        a = fractional power

% output: Faf = fast Fractional Fourier transform

error(nargchk(2, 2, nargin));

f = f(:);

N = length(f);

shft = rem((0:N-1)+fix(N/2),N)+1;

sN = sqrt(N);

a = mod(a,4);

% do special cases

if (a==0), Faf = f; return; end;

if (a==2), Faf = flipud(f); return; end;

if (a==1), Faf(shft,1) = fft(f(shft))/sN; return; end

if (a==3), Faf(shft,1) = ifft(f(shft))*sN; return; end

% reduce to interval 0.5 < a < 1.5

if (a>2.0), a = a-2; f = flipud(f); end

if (a>1.5), a = a-1; f(shft,1) = fft(f(shft))/sN; end

if (a<0.5), a = a+1; f(shft,1) = ifft(f(shft))*sN; end

% the general case for 0.5 < a < 1.5

alpha = a*pi/2;

tana2 = tan(alpha/2);

sina = sin(alpha);

f = [zeros(N-1,1) ; interp(f) ; zeros(N-1,1)];

% chirp premultiplication

chrp = exp(-i*pi/N*tana2/4*(-2*N+2:2*N-2)'.^2);

f = chrp.*f;

% chirp convolution

c = pi/N/sina/4;

Faf = fconv(exp(i*c*(-(4*N-4):4*N-4)'.^2),f);

Faf = Faf(4*N-3:8*N-7)*sqrt(c/pi);

% chirp post multiplication

Faf = chrp.*Faf;

% normalizing constant

Faf = exp(-i*(1-a)*pi/4)*Faf(N:2:end-N+1);

%%%%%%%%%%%%%%%%%%%%%%%%%

function xint=interp(x)

% sinc interpolation

N = length(x);

y = zeros(2*N-1,1);

y(1:2:2*N-1) = x;

xint = fconv(y(1:2*N-1), sinc([-(2*N-3):(2*N-3)]'/2));

xint = xint(2*N-2:end-2*N+3);

%%%%%%%%%%%%%%%%%%%%%%%%%

function z = fconv(x,y)

% convolution by fft

N = length([x(:);y(:)])-1;

P = 2^nextpow2(N);

z = ifft( fft(x,P) .* fft(y,P));

z = z(1:N);