Time delay an OFDM Signal

Hi,

I want to delay an OFDM signal in time domain (MATLAB): 


sig= signal
ipIndex = interpolation index
--------------------------------------------------------------------
% Interpolation
iq_ip = interp(sig,ipIndex);

% Delay the signal
delayed_iq_ip = [iq_ip(end-delayIndex+1:end); iq_ip(1:end-delayIndex)];

% Reduce the sampling rate 
r=1;
for sample = 1:ipIndex:length(delayed_iq_ip),
    iq_d(r,1) = delayed_iq_ip(sample,1);
    r = r+1;
end

sig_delayed = iq_d;
------------------------------------------------------------------------

I am not sure, if this way of delaying the signal is right. 
% Delay the signal
delayed_iq_ip = [iq_ip(end-delayIndex+1:end); iq_ip(1:end-delayIndex)];

Is it better just to add zeros in the beginning of the signal?I have to
compensate this delay in the transmitter before the FFT. 

Thank you.

emeto