MATLAB: Fractional delay using FFT,IFFT

fractional delayinteger+fractional delayphase delay

Hello, I have been working on delaying any given signal with subsample accuracy (fractional+interger) delay in Frequency domain which results in simple phase change. I know there are functions available in toolboxes(example delayseq), but I would like to do it manually in my program. Here is the code i have written so far:
 clc
 clear all
 close all
  Fs=1000;
  T = 1/Fs;                     % Sample time
  L = 1000;                     % Length of signal
  t = (0:L-1)*T;  
  delta_T=2.345; %delay time in milliseconds
  % Time vector
x = sin(2*pi*50*t);
w=2*pi*50; %angular freq. component 
X=fft(x);
Y=X.*exp(-j*w*t*delta_T);
y_1=abs(ifft(Y));
%plot signals
figure;
plot(Fs.*t(1:50),x(1:50))
hold on;
plot(Fs*t(1:50),y_1(1:50),'r');
legend('Original signal','shifted signal');
xlabel('time (milliseconds)')
ylabel('amplitude');
[[Note: I have edited my previous code.]]
My goal is to delay or advance the above signal x (sine) by any amount of time (lets say by 2.345 milliseconds)
Iam getting a weird plot!! 🙁
Please help me what am I missing?
Thanks!

Best Answer

You probably should not be multiplying X(1) by the delay, as X(1) is the DC magnitude that scales the rest of the values.
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