Why hardware FIR filters (FIR filters) are doing the FFT?
Probably a very stupid question, but the direct answer I never found. For example given the task to design conveyor hardware FIR filter (FIR-filter), for example on 1024 points. Why usually do it using FFT (Fast Fourier transform, FFT), and not in the forehead by the formula of convolution? It would seem each successive step of the conveyor does not increase the clock frequency and the area increases linearly. Isn't it?
I can not quite in the subject, but where this is the case? And hardware FIR is usually not projecting, he is already inside the crystal, you only need to configure. And so there is an assumption that one and the same unit, considering FFT is used for filters, convolution, FFT/DCT, to save space on the chip