DT Signal Fourier Coefficients
Let's make up a signal.
$ x[0] = 0 $
$ x[1] = 1 $
$ x[2] = 1 $
$ x[3] = 0 $
$ x[4] = x[0] $ etc, the function is periodic with period 4
Using the formula
$ x[n] = \sum_{k=0}^{N-1} a_k e^{jk \frac{2 \pi}{N} n} $, where $ a_k = \frac{1}{N} \sum_{r=0}^{N-1} x[r] e^{-jk \frac{2 \pi}{N} r} $
Since the period is 4, N=4.
$ x[n] = \sum_{k=0}^{3} a_k e^{jk \frac{2 \pi}{4} n} $, where $ a_k = \frac{1}{4} \sum_{r=0}^{3} x[r] e^{-jk \frac{2 \pi}{4} r} $
