In the digital communication system, the DFT stands for Discrete Fourier transform, it is a finite duration frequency sequence which is obtained by sampling one period of Fourier transform. Sampling is done at 'N' equally spaced points, over the period extending from o to around range of 2π.
Mathematical equations :
The DFT of discrete sequence sequence is x(n) and is denoted by X(k). It is given by,
N-1
X(K) = ∑ x(n) . e –j2πkn/N
n=0
Here k = 0,1,2,3.......N-1
Since this summation is taken for N point, it is called as N point of discrete Fourier transform called DFT.
We can obtain a discrete sequence x(n) from its DFT. It is called an inverse discrete Fourier transform. It is given by,
X(n) =1/N ∑ x(k) . e –j2πkn/N
k=0
Here n = 0,1,2,3.......N-1
This is called as N point IDFT.