First the FFT of $$x[n]=[1, 1, 1, 1]$$ and its inverse for $N=2^3$ [![enter image description here][1]][1] where red dot indicates sample location. Now shift samples as given by you, [![enter image description here][2]][2] I may be totally wrong but keen to learn my mistakes [1]: https://i.sstatic.net/4TaW3.png [2]: https://i.sstatic.net/WuxAE.png