Slow matlab code

function p=SDC(signal)
 
%functions to compute shifted delta cepstral from MFCC,PLP,LPC
%
%Signal is coeff of MFCC
 
%Author Tommy Strømhaug, 2008
 
%Hardcoded N, d, P, and k
 
%d and P considered in frames. N amd k is ints
N=7;  % number of c cepstral coefficients in each cepstral vector
d=1;  % time advance and delay for the delta computation
P=3;  % timeshift netween consecutive blocks
k=7;  % number of blocks whose delta coefficients are concatenated to form the SDC vector
 
[row,col]=size(signal);
sdc=[];
sdc_temp=[];
 
%Pad data to not get out of bound. circular padding
right=signal(:,col-9:col)
left =signal(:,1:21)
signal=cat(2,signal,left);
signal=cat(2,right,signal);
 
for t=11:col+10
        
    for i=0:k-1
        
        sdc_temp=signal(:,t+i*P+d)-signal(:,t+i*P-d);
        sdc=cat(2,sdc,sdc_temp);     
        
      end    
end
 
p=sdc;