Tootfinder

Low-Complexity Equalization of Zak-OTFS in the Frequency Domain
Sandesh Rao Mattu, Nishant Mehrotra, Saif Khan Mohammed, Venkatesh Khammammetti, Robert Calderbank
https://arxiv.org/abs/2508.07148

Low-Complexity Equalization of Zak-OTFS in the Frequency Domain
4G/5G wireless standards use orthogonal frequency division multiplexing (OFDM) which is robust to frequency selectivity. Equalization is possible with a single tap filter, and low-complexity equalization makes OFDM an attractive physical layer. However the performance of OFDM degrades with mobility, since Doppler spreads introduce inter-carrier interference (ICI) between subcarriers and they are no longer orthogonal. Zak-transform based orthogonal time frequency space (Zak-OTFS) modulation has …

Zak-OFDM: Low Complexity Joint Equalization of OFDM Carriers in Doubly-Spread Channels
Saif Khan Mohammed, Sandesh Rao Mattu, Nishant Mehrotra, Venkatesh Khammammetti, Robert Calderbank
https://arxiv.org/abs/2506.23045

Zak-OFDM: Low Complexity Joint Equalization of OFDM Carriers in Doubly-Spread Channels
We communicate over wireless channels by first estimating and then equalizing the effective channel. In Zak-OTFS (orthogonal time frequency space) modulation the carrier waveform is a pulse in the delay-Doppler (DD) domain, formally a quasi-periodic localized function with specific periods along delay and Doppler. When the channel delay spread is less than the delay period, and the channel Doppler spread is less than the Doppler period, the response to a single Zak-OTFS carrier provides an imag…