Howtosignalprocessing
- Why is FFT output complex?
- Why is FFT used in signal processing?
- What are the outputs of FFT?
- Why is FFT output mirrored?
- What is the meaning of conjugate symmetry?
Why is FFT output complex?
Why does FFT produce complex numbers instead of real numbers? The reason FT result is a complex array is a complex exponential multiplier is involved in the coefficients calculation. The final result is therefore complex. FT uses the multiplier to correlate the signal against multiple frequencies.
Why is FFT used in signal processing?
The FFT is used to process data throughout today's highly networked, digital world. It allows computers to efficiently calculate the different frequency components in time-varying signals—and also to reconstruct such signals from a set of frequency components.
What are the outputs of FFT?
These frequencies actually represent the frequencies of the two sine waves which generated the signal. The output of the Fourier transform is nothing more than a frequency domain view of the original time domain signal.
Why is FFT output mirrored?
Because both the positive and negative frequency sinusoids are 90 degrees out of phase and have the same magnitude, they will both respond to real signals in the same way.
What is the meaning of conjugate symmetry?
Conjugate symmetric means. f(−x)=f∗(x) i.e. the sign of the imaginary part is opposite when x<0. The FFT of a real signal is conjugate symmetric. One half of the spectrum is the positive frequencies, and the other half is the negative.
