As length of signal increases, frequency spacing reduces, approximation error representation of spectrum decreases, resolution of spectrum increases, missing values in less point DFT are present in more point DFT.
https://drive.google.com/drive/folders/0BwvLoQVdPTK3SzVXUW5CYWpvOWc
https://drive.google.com/drive/folders/0BwvLoQVdPTK3SzVXUW5CYWpvOWc
DFT is nothing but sampling DTFT in frequency domain.and spectrum of DFT is discrete since input is periodic.
ReplyDeleteThe Discrete Fourier transform (DFT) converts a finite sequence of equally spaced samples of a function into the list of coefficients of a finite combination of complex sinusoids, ordered by their frequencies, that has similar sample values.
ReplyDeleteDFT though a simpler method, FFT has less number of complex and real multiplications and additions so it is preferred
ReplyDeleteDigital domain requires samples of the signal in frequency domain. We use DTFT to convert the analog signal to digital signal and use DFT to get samples of it.
ReplyDelete