Convolution on one side of an FFT is a time-consuming N^2 problem per dimension. On the other side of an FFT, it merely becomes a multiplication - the dual operation of convolution.
It is usually far more efficient to Fourier transform, multiply, and transform back than to brute-force convolve.
Correlation is used to obtain the similarity between two signals.
It is used in Radars where the similarity between the transmitted and the received signal is to be found out. This is where the correlation will become useful.
Talking about DFT, it is a transform that is used to make certain infinite length calculations easy and fast.
I am doing project on fpga digital multimeasurement system using fir and iir lowpass filters
Can anyone tell me how can we measure different parameters using low pass filter like frequency, amplitude etc