High-Speed Moving Target Communication Technology in Shallow Sea Based on Random-OTFS

Orthogonal Time Frequency Space (OTFS) modulation is a new type of signal modulation method proposed in recent years. It aims to address the problem of communication quality degradation caused by Doppler frequency shift in the typical high-mobility and multipath transmission scenarios of next-generation wireless communication networks. For underwater acoustic communication in high-speed mobile environments, the Doppler effect is very significant and complex, including frequency spreading and frequency offset. Meanwhile, the bandwidth of underwater acoustic communication is usually narrow, and the OTFS modulation uses broadband signals. When there is a Doppler effect in the channel, it will inevitably have additional impacts. To solve the above problems, based on the traditional OTFS modulation technology, this paper proposes a Random-OTFS modulation technology that uses complex Gaussian random sequences as carrier signals and directly modulates information in the Doppler time-domain stretching region. This technology can resist relatively strong Doppler interference, reduce signal distortion, and better adapt to the rapid changes of underwater acoustic channels, with stronger adaptability to channel characteristics.