Analog filters signal transmission

The signal band (formerly centered at, ) is thus shifted to dc. The following digital FIR filter with transmission zeros at, 2 fm, and 3 fm cancels out the dc offsets and 1/f noise of the analog front-end (now centered at fm) as well as some overtones of the original square wave abased into the Nyquist band of the signal sampled at 4 fm. 

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