Comparative analysis and modeling of underwater acoustic channels

Abstract

Research agencies like Naval Research board, India work towards design and development of marine systems which includes underwater acoustic systems/devices and oceanographic systems and identified open research areas that include low frequency acoustic propagation study in shallow waters, reliable high data rate communication,investigation of TRM and MIMO-OFDM methods for underwater acoustic communication. In order to support reliable high data rate communication, it is necessary to model, measure, and characterize the UWA channel to determine the details of its multipath and Doppler characteristics. The main aim of the research work is to provide Comparative Analysis and Modeling of Doppler Effect in Underwater Acoustic Channel. newlineUnderwater acoustic channel is characterized by attenuation losses, reflection loss delay spread and Doppler spread. Statistical models that can be considered for the signal fading include Rician, Nakagami and log-normal distributions of the path responses. As sea trials are expensive, simulators are required to study the channel behavior. The basic parameters involved in acoustic channel Modeling are the speed of the sound, salinity, sea surface and sea floor, transmission loss, attenuation and spreading loss. The data set is a collection of recorded acoustic signals and environmental measurements necessary to model the channel. Several agencies have conducted experiments to collect the oceanographic data. In this work, environment data sets of INDMOD project, SWAM99 benchmark environment and communication parameters of MACE Experiment are considered. newline newlineThe channel can be modeled by empirical methods or numerical methods. Empirical methods require experimentation to derive the statistical characteristics of the Channel. Numerical methods involve solution to wave equations. In this research work, various factors contributing to the Doppler shift and modeling techniques characterizing the Doppler Effect in the channel model are analyzed. In Ray tracing model, Doppler Effect is modeled in