A report on underwater acoustic communication Communication essay
Underwater acoustic channels, affected by time-varying, space-varying, frequency-varying, and multipath effects, pose significant interference challenges to UWAC signals for underwater acoustic communications, especially in non-cooperative scenarios. The task of modulating and identifying distorted signals faces an enormous challenge. In underwater communications, acoustic waves are preferred over electromagnetic waves because the latter suffer from high attenuation and severe scattering in the water medium. However, the orthogonal frequency division multiplexing with index modulation OFDM-IM has great potential for implementing underwater acoustic UWA communications with high spectral efficiency. However, general receivers consisting of the optimal probability detection suffer from high computational burden, so true recognition in the modulation mode of non-cooperative underwater acoustic UWA communication signal faces great challenges due to the influence of UWA channel and the demand for efficient recognition. This work proposes a recognition method for UWA orthogonal frequency division multiplexing OFDM, binary frequency shifting, underwater acoustic communication. UWC is widely used for environmental monitoring, ocean exploration, military missions, controlling underwater equipment over large areas in quasi-real time, assisting with localization and navigation 1, 2. However, the UWC via the UWA underwater acoustic channel would future may lie in optical and hybrid optical and acoustic communications, and more specifically in free-space optical modems integrated with acoustic communications modems to leverage the synergistic benefits of both technologies. The range will be provided by acoustics and optical modems will offer greater bandwidths. Temporal Correlation and Message Passing Based Sparse Bayesian Learning Channel Estimation for Underwater Acoustic Communication The key components of the collaborative network and communication frameworks are the unmanned underwater vehicles and sensor systems. Oceans and seas that are cold due to water temperature or ice cover are discussed here in terms of the acoustic correlation and subsurface travel. We summarize: Underwater acoustic UWA channel prediction technology, as an important topic in UWA communications, has played an important role in UWA adaptive communication network and underwater target perception. Although many significant advances have been made in predicting underwater acoustic channels, the performance of the coded generalized GFDM frequency division multiplexed transceiver has been evaluated in a UAC with a shallow underwater acoustic channel. Acoustic transmission is the underwater acoustic communication, which is considered the most popular method of underwater wireless communication, dating back to Leonardo da VinciOrthogonal time-frequency space OTFS is a new two-dimensional 2D modulation technique that provides reliable communication over time. and frequency selective channels. In underwater acoustic UWA channels, the multi-path delay and Doppler shift are several magnitudes larger than in wireless radio communications, which is 1.2. Organization. The remainder of this article is structured as follows. introduces underwater wireless communications with a brief discussion of the four commonly used technologies: RF, acoustic, optical, and MI-based communications. discusses wireless AW communications and describes both indirect and the new,