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A Discrete Fourier Transform is simply the name given to the Fourier Transform when it is applied to digital (discrete) rather than an analog (continuous) signal. An FFT (Fast Fourier Transform) is a faster version of the DFT that can be applied when the number of samples in the signal is a power of two. An FFT computation takes approximately N * log2(N) operations, whereas a DFT takes approximately N^2 operations, so the FFT is significantly faster

simple answer is

FFT = Fast DFT

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Why FFT is faster than DFT?

FFT is faster than DFT because no. of complex multiplication in DFT is N^2 while in FFT no. of complex multiplications are N/2(log2N). for example if N=8 no. of complex multiplications required in DFT are 64. while no. of complex multiplications required in FFT are 12 thus reduces computation time.


What is Fast Fourier Transform in matlab?

The Fast Fourier Transform (FFT) in MATLAB is an efficient algorithm used to compute the discrete Fourier transform (DFT) and its inverse. It allows for the transformation of a time-domain signal into its frequency-domain representation, facilitating analysis and processing of signals. MATLAB provides built-in functions like fft for performing FFT, making it easy to analyze signal frequencies, perform filtering, and apply other signal processing techniques. The FFT significantly reduces computational complexity compared to directly calculating the DFT, especially for large datasets.


What are the differences between dft and idft?

idft is inverse of dft


How do you compute linear convolution using DFT?

By making use of periodicities in the sines that are multiplied to do the transforms, the FFT greatly reduces the amount of calculation required. Here's a little overview. Functionally, the FFT decomposes the set of data to be transformed into a series of smaller data sets to be transformed. Then, it decomposes those smaller sets into even smaller sets. At each stage of processing, the results of the previous stage are combined in special way. Finally, it calculates the DFT of each small data set.


What are there advantages and where are there used fft?

because they have a high speed compared to fft


What are there advantages and where are there used?

FFT reduces the computation since no. of complex multiplications required in FFT are N/2(log2N). FFT is used to compute discrete Fourier transform.


What is the basic difference between ofdma and sc-fdma?

The basic difference between OFDMA and SC-FDMA is that, there there is an additional block of N point DFT before the sub-channel mapping in SC-FDMA. This will effectively reduce the PAPR, thus the power amplifier will have a lesser linear range in SC-FDMA when compared with OFDMA


How do you plot frequency spectrum using fft function in MATLAB?

plot(abs(fft(vectorname)))the FFT function returns a complex vector thus when you plot it, you get a complex graph. If you plot the absolute value of the FFT array, you will get the magnitude of the FFT.


What the procedure of dft?

The procedure of DFT can be found by following this website: gov.uk/government/organisations/department-for-transport/about/complaints-procedure.


Need of fft?

FT is needed for spectrum analysis, FFT is fast FT meaning it is used to obtain spectrum of a signal quickly, the FFT algorithm inherently is fast algorithm than the conventional FT algorithm


Difference between DIT DIF?

the diff between the two lies in their very names - decimation is time and decimation in freq. when u say decimation on time, u will consider the individual samples(actually pair of samples) in time domain n find their freq parts and go further and further to find the fft. when u say decimation on freq, u will consider the individual samples in freq domain n combine them to come out with the actual fft.


What is the need of FFT?

There's no need for it.