Orthogonal Delay Scale Space Modulation: A New Technique for Wideband Time-Varying Channels

Orthogonal Time Frequency Space (OTFS) modulation is a recently proposed scheme for time-varying narrowband channels in terrestrial radio-frequency communications. Underwater acoustic (UWA) and ultra-wideband (UWB) communication systems, on the other hand, confront wideband channels. Unlike channels, which time contractions or dilations due to Doppler effect can be approximated by frequency-shifts, results frequency-dependent non-uniform shift of signal frequencies across band. In this paper, we develop an OTFS-like -- Delay Scale (ODSS) handling We derive ODSS transmission reception schemes from first principles. process, introduce notion -convolution delay-scale space that parallels twisted convolution used time-frequency space. The preprocessing 2D transformation Fourier-Mellin domain ODSS, plays role inverse simplectic Fourier transform (ISFFT) OTFS, improves bit error rate performance compared OTFS Division Multiplexing (OFDM) Furthermore, since channel matrix rendered near-diagonal, retains advantage OFDM terms its low-complexity receiver structure.