Design and analysis of a one-dimensional sea surface simulator using the sum-of-sinusoids principle

Simulators for sea surface waves are useful for many practical applications, such as the construction of offshore structures and ocean surface animations. This paper studies three methods for the design of one-dimensional sea surface waves simulators with given wave spectra using the sum-of-sinusoids (SOS) principle. The wave spectrum provides insight into important statistical properties of the sea surface waves, such as the autocorrelation function (ACF) of the sea surface waves, significant wave height, and the moments of the spectrum. The sea surface simulator is designed by applying the concept of deterministic channel modelling on two main classical wave spectra, namely the Pierson-Mo…

A Geometry-Based Underwater Acoustic Channel Model Allowing for Sloped Ocean Bottom Conditions

This paper proposes a new geometry-based channel model for shallow-water ocean environments, in which the ocean bottom can slope gently down/up. The need for developing such an underwater acoustic (UWA) channel model is driven by the fact that the standard assumption of a flat ocean bottom does not hold in many realistic scenarios. Starting from a geometrical model, we develop a stochastic channel model for wideband single-input single-output vehicle-to-vehicle UWA channels using the ray theory assuming smooth ocean surface and bottom. We investigate the effect of the ocean-bottom slope angle on the distribution of the channel envelope, instantaneous channel capacity, temporal autocorrelati…

A geometry-based channel model for shallow underwater acoustic channels under rough surface and bottom scattering conditions

Modelling, Analysis, and Simulation of Underwater Acoustic Channels : Doctoral Dissertation for the Degree Philosophiae Doctor (PhD) at the Faculty of Engineering and Science, Specialization in Information and Communication Technology

Modelling the Doppler Power Spectrum of Non-Stationary Underwater Acoustic Channels Based on Doppler Measurements

This paper proposes a non-stationary time-continuous simulation model for wideband shallow underwater acoustic (UWA) channels based on measured Doppler power spectrums (DPSs). Measurement-based channel simulators are essential for the test, optimization, and performance analysis of UWA communication systems. The aim is to fit the DPS of the simulation model to that of the measured UWA channel. The performance of the designed UWA channel simulator is assessed by comparing the average Doppler shift and Doppler spread of the channel simulator with the corresponding quantities of the measured UWA channel. The results of the assessment show a good match between the statistical quantities of the …

Performance analysis of Alamouti-coded OFDM systems over spatio-temporally correlated underwater acoustic channels

In this paper, we analyze the performance of Alamouti-coded orthogonal frequency division multiplexing (OFDM) systems over time-varying underwater acoustic (UWA) channels. A realistic UWA channel model has been considered, which can be correlated in either time or space or simultaneously in both domains. An exact analytical expression for the bit error probability (BEP) is necessary to analyze accurately the performance of Alamouti-coded OFDM systems over the spatio-temporally correlated UWA channel model. Hence, by using this UWA channel model, an expression has been derived for the BEP of Alamouti-coded OFDM systems assuming that the receiver knows perfectly the channel state information.…

The design of measurement-based underwater acoustic channel simulators using the INLSA algorithm

This paper utilizes the iterative nonlinear least square approximation (INLSA) algorithm for designing measurement-based wideband shallow underwater acoustic (UWA) channel simulators. Measurement-based channel simulators are essential for the test, optimization, and performance analysis of UWA communication systems. The aim is to fit the time-variant channel impulse response (TVCIR) of the simulation model to that of the measured UWA channel. The performance of the designed UWA channel simulator is assessed by comparing the time-frequency correlation function (TFCF), the power delay profile (PDP), and the probability density function (PDF) of the channel envelope with the corresponding quan…

A Nonisovelocity Geometry-Based Underwater Acoustic Channel Model

This paper proposes a new geometry-based shallow underwater acoustic (UWA) channel model allowing for nonisovelocity ocean conditions. The fact that the isovelocity assumption does not hold in many real-world scenarios motivates the need for developing channel models for nonisovelocity UWA propagation environments. Starting from a geometrical model, we develop a stochastic channel model for a single-input single-output (SISO) vehicle-to-vehicle UWA channel assuming that the ocean surface and bottom are rough and that the speed of sound varies with depth. The effect of the nonisovelocity condition has been assessed regarding its influence on the temporal autocorrelation function, the frequen…