Cyclic prefix interpretation in frequency domain

[Ahmed Alaa]

Dear all,

In the frequency domain, OFDM maintains orthogonality because nulls of adjacent subcarriers are co-located with the maxima of targeted subcarriers. However, adding CP and keeping subcarrier spacing will cause the nulls to be shifted and orthogonality seems to be not maintained !! I understand the issue in time domain but can't figure it out in the freq domain.

Can any one explain how CP maintains orthogonality in freq domain ?

 

[alqasim]

CP function is to avoid the effect of inter-symbol interference due to signal multipath phenomena

check the attached , it may help you .