Fig. 2: Spectral efficiency as a function of maximum delay and Doppler spread.
From: Low-complexity equalization of Zak-OTFS in the frequency domain

OFDM spectral efficiency has a large variance and drops down to zero at high Doppler spread.
From: Low-complexity equalization of Zak-OTFS in the frequency domain

OFDM spectral efficiency has a large variance and drops down to zero at high Doppler spread.