Adaptive Damping Log-Domain Message-Passing Algorithm for FTN-OTFS in V2X Communications.

Area of Science:

• Wireless Communications
• Signal Processing
• Information Theory

Background:

• Vehicle-to-everything (V2X) communications face challenges from severe Doppler effects and time-varying channels.
• Existing modulation schemes struggle to maintain reliability and spectral efficiency in high-mobility V2X environments.
• The need for advanced modulation techniques is critical for next-generation V2X systems.

Purpose of the Study:

• To propose a novel modulation scheme for highly reliable and spectrum-efficient V2X communications.
• To enhance symbol-transmission density within existing resource blocks without increasing bandwidth.
• To address the limitations of current V2X communication methods in dynamic channel conditions.

Main Methods:

• Integration of faster-than-Nyquist (FTN) signaling with spectrally efficient frequency division multiplexing (SEFDM) within the orthogonal time frequency space (OTFS) framework.
• Derivation of an analytical input-output model in both delay-Doppler and time-frequency domains.
• Development of an adaptive damping log-domain message-passing (ADL-MP) detection algorithm for improved numerical stability.

Main Results:

• The proposed FTN-OTFS scheme demonstrates robust and reliable performance in high-mobility scenarios.
• The ADL-MP algorithm significantly outperforms conventional methods in bit error rate (BER) under Extended Vehicular A (EVA) and high-speed train (HST) models.
• Enhanced spectral efficiency is achieved without compromising occupied bandwidth.

Conclusions:

• The novel FTN-OTFS modulation scheme is effective for V2X communications, particularly in high-mobility conditions.
• The proposed scheme and ADL-MP algorithm offer a superior solution for reliable and spectrally efficient V2X.
• This advancement is crucial for the future development of V2X communication systems.