We had to compute a signal's [x(n)] Fourier Transform and observe the Magitude Spectrum. Two cases were taken, first was a signal with length equal to 4 and second was the first signal with zero padding to make its length 8. DFT was calculated using the C code, run through Linux terminal. It was observed that DFT always give periodic results and increasing the length by zero padding of signal gives better approximation of signal and resolution of spectrum increases.As N increases frequency spacing reduces, approximation error decreases and resolution improves.
Link:-
DFT
IDFT
Link:-
DFT
IDFT
MENTION THE EFFECT ON RESOLUTION
ReplyDeleteMENTION THE EFFECT ON RESOLUTION
ReplyDeleteResolution increases because frequency spacing reduces since length increases.
DeleteSpacing between the values reduces as the value of N increases. By appending the input sequence by zeros the resolution error reduces.
ReplyDeleteThe magnitude spectrum is periodic due to the characteristic of twiddle factor
ReplyDeleteby appending more zeroes, the missing values in less point DFT are present in the DFT with more point.
ReplyDelete