Impulse Response Modeling of Underwater Optical Scattering Channels for Wireless Communication

Abstract

Despite the fact that underwater optical wireless communication (UOWC) systems are able to provide high-data rate links with high security, the performance of these systems presents several limitations related to the maximum achievable distance due to attenuation, and scattering effects. Hence, quantifying the signal attenuation, and the time-dispersion produced by such effects represents a crucial work in channel modeling. Motivated by this, we present, for the first time, a novel, and unified impulse response modeling of underwater optical scattering channels based on the superposition of one impulsive component, and one dispersive component with two degrees of freedom. We provide analytical results for channel path loss, and channel impulse response (CIR) which are validated through Monte-Carlo simulations based on photon-tracing for clear ocean, coastal, and harbor waters. In order to provide a physical insight, the developed CIR is used to compute the root-mean-square (RMS) delay spread as a function of distance, and type of water, as well as to analyze in greater detail the impact of inter-symbol interference (ISI) on the data rate. These outcomes can be used for high-speed systems design, and optimization.

Performance Analysis and Design Considerations of the Shallow Underwater Optical Wireless Communication System with Solar Noises Utilizing a Photon Tracing-Based Simulation Platform

“…Using the Monte Carlo statistical method, authors in [18] simulated and analyzed the laser spot-expansion and time-domain broadening characteristics of the UOWC link. The most recent work was presented in [19], here they proposed a novel UOWC channel modeling method based on the mixture of two Gamma functions, the results were validated through Monte-Carlo simulations and exhibited reasonable agreement. The aforementioned works on UOWC channel modeling are summarized in Table 1.…”

“…In terms of experimental channel measurement, researchers in [13] established an experimental testbed to study the LD-UOWC channel characteristics by measuring the intensity of the light transmitted through different types of water. To overcome these limitations, the Monte Carlo numerical simulation method was developed to solve RTE and model the underwater channel; several works were reported in [14][15][16][17][18][19]. In [14], a Monte Carlo (MC) based approach was proposed to investigate the light attenuation and time-domain broadening effects in different types of seawater channels, the impact of the water quality, communication distance, and receiver aperture were also analyzed.…”

Connectivity Analysis of Underwater Optical Wireless Sensor Networks

“…Beam Lambert's law assumes that scattered photons have no chance of being received by the receiver. In practice, the range of an optical connection depends on parameter c and varies for different types of water [24].…”

Low Complexity Single Carrier Frequency Domain Detectors for Internet of Underwater Things (IoUT)s

“…[1][2][3][4][5][6][7][8][9][10][11], and references therein. The peculiar nature of the underwater channel makes it very difficult to satisfy the above-mentioned IoUT application requirements [12,13].…”

“…The underwater communication poses adverse channel conditions due to high attenuation, a large number of multipath, variable propagation delay spread, and susceptibility to Doppler shift between the source and the destination [5]. It is also very difficult to maintain line of sight (LOS) communication which results in significant signal attenuation [12,13]. Furthermore, the intersymbol interference (ISI) span is very different in shallow and deep water [14].…”