Hi all, I'm trying to find an even lengthed sequence of FIR coefficients where every coefficient will be one of the five: 1, -1, 0, j, -j. I'm looking for a sequence whose FFT will have one notch (or at least a 20dB attenuation relative to other frequency samples) at a certain frequency. I'm hoping to find different sequences so that each sequence will have a notch (or attenuation) at a different frequency sample. I know that the literature is full with articles about low-correlation frequencies, some of them (e.g. Legendre sequences) have notch at DC frequency. This is good, but i'm looking for the ability to have notches at all frequency samples, not just the DC (besides, Legendre sequences have odd length). Could anyone help me with relevant information about this subject? Thank you in advance, Dan
Constructing frequency notch FIR filters using 5 phase sequence
Started by ●November 3, 2008