6G • RAN
OTFS (Orthogonal Time Frequency Space)
Delay-Doppler Domain Orthogonal Modulation for High-Mobility 6G
Revolutionary modulation scheme placing data symbols in the delay-doppler domain rather than the time-frequency domain to conquer high mobility.
Technical Explanation
Traditional OFDM struggles in high-mobility 6G environments (high-speed trains, LEO satellites, drones) because severe Doppler shifts cause Inter-Carrier Interference (ICI) and destroy orthogonality. OTFS maps information symbols onto the delay-doppler domain using the Inverse Symplectic Finite Fourier Transform (ISFFT). In this domain, rapidly time-varying multipath channels transform into quasi-static, localized geometry, delivering robust multi-gigabit communication at extreme velocities.
Key Functions
- Maps information symbols onto the Delay-Doppler coordinate domain
- Transforms fast-fading time-varying channels into invariant channel representations
- Eliminates Doppler-induced inter-carrier interference on high-speed mobile links
- Provides ideal dual-functionality for simultaneous communications and radar sensing
Specifications
3GPP Rel-19 Modulation Study, IEEE Transactions on Wireless Communications
Interfaces
ISFFT/SFFT Transform CoreDelay-Doppler Channel Estimator
Related 6G Concepts
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