The criteria for selecting the window function in Periodogram in (FBMC vs. OFDM Modulation) example.

Hi everyone.

In the example ( FBMC vs. OFDM Modulation ), Periodogram function uses Hann window for FBMC modulation , while it uses Rectangular window (rectwin) for OFDM.

FBMC

[specFBMC, fFBMC] = periodogram(currSym, hann(KF, 'periodic'), KF*2, 1);

OFDM

 [specOFDM,fOFDM] = periodogram(ifftOut, rectwin(length(ifftOut)), ...
        numFFT*2, 1, 'centered');

Is there any explanation ?