In this eperiment we took entries of x(n) and found out its Discrete Fourier Transform.
It was done for two values of N namely N=4 and N=8. IDFT was performed to verify the result.We observed that as the spacing between the values reduces the value of N increases. Also the quality of spectrum obtained improves. By apending the input signal by zeros the resolution error reduces.
https://drive.google.com/file/d/0B9zlXLFfOipjbkloRXgyQVMtYWM/view?usp=sharing
https://drive.google.com/file/d/0B9zlXLFfOipjTEhkY2xpSlpfUjQ/view?usp=sharinghttps://drive.google.com/file/d/0B9zlXLFfOipjTEhkY2xpSlpfUjQ/view?usp=sharing
It was done for two values of N namely N=4 and N=8. IDFT was performed to verify the result.We observed that as the spacing between the values reduces the value of N increases. Also the quality of spectrum obtained improves. By apending the input signal by zeros the resolution error reduces.
https://drive.google.com/file/d/0B9zlXLFfOipjbkloRXgyQVMtYWM/view?usp=sharing
https://drive.google.com/file/d/0B9zlXLFfOipjTEhkY2xpSlpfUjQ/view?usp=sharinghttps://drive.google.com/file/d/0B9zlXLFfOipjTEhkY2xpSlpfUjQ/view?usp=sharing
DFT always give periodic results and increasing the length by zero padding of signal gives better approximation of signal and resolution of spectrum increases.
ReplyDeleteAlso when signal is expanded in time domain it is compressed in frequency domain
Deleteby appending more zeroes, the missing values in less point DFT are present in the DFT with more point.
ReplyDeleteAs n increases the observed spectrum is smoother and frequency spacing reduces.
ReplyDelete