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

Abstract

The performance of the underwater optical wireless communication (UOWC) system is highly affected by seawater´s inherent optical properties and the solar radiation from sunlight, especially for a shallow environment. The multipath effect and degradations in signal-to-noise ratio (SNR) due to absorption, scattering, and ambient noises can significantly limit the viable communication range, which poses key challenges to its large-scale commercial applications. To this end, this paper proposes a unified model for underwater channel characterization and system performance analysis in the presence of solar noises utilizing a photon tracing algorithm. Besides, we developed a generic simulation platform with configurable parameters and self-defined scenarios via MATLAB. Based on this platform, a comprehensive investigation of underwater channel impairments was conducted including temporal and spatial dispersion, illumination distribution pattern, and statistical attenuation with various oceanic types. The impact of ambient noise at different operation depths on the bit error rate (BER) performance of the shallow UOWC system was evaluated under typical specifications. Simulation results revealed that the multipath dispersion is tied closely to the multiple scattering phenomenon. The delay spread and ambient noise effect can be mitigated by considering a narrow field of view (FOV) and it also enables the system to exhibit optimal performance on combining with a wide aperture.

Enhancing Security of TAS/MRC-Based Mixed RF-UOWC System With Induced Underwater Turbulence Effect

“…For a mixed dual-hop system configuration, performance metrics, i.e., ASC, SOP, and probability of SPSC are analyzed graphically in this section to investigate the influence of system parameters on the secrecy performance of the proposed framework. In order to verify the accuracy of developed novel expressions in (20), (29), (34), and (40), MC simulations are performed by generating 10 6 independent random samples in MATLAB and we notice a close match between analytical and simulation results. Moreover, bivariate Fox's H function can not directly be evaluated using Mathematica or Maple since there is no built-in function for that purpose and hence [30, Table I] is utilized to implement this function in Mathematica.…”

“…Zhang et.al implemented blue and green laser diodes for nonorthogonal multiple access (NOMA) based UOWC system to establish a high data speed network [18]. Several encryption methods were reported in [19], [20] over the UOWC network that reveals the feasibility of the proposed network under several water turbidities and shallow environments. A recent investigation developed mixture exponential-generalized Gamma (mEGG) distributions that characterize various UWT conditions (i.e.…”

“…By placing ( 14) and ( 17) into (19), analytical expression of ASC is derived as (20), where A 1 , A 2 , A 3 , A 4 , A 5 , A 6 , A 7 , and A 8 are the eight integral terms determined as follows. A 1 is derived as…”

Accurate Underwater Optical Wireless Communication Model With Both Line-of-Sight and Non-Line-of-Sight Channels

“…We denote the transmittance of TFF as T f (λ, θ in ), which is the ratio of transmitted optical power after optical filter to the incident optical power, and it can be described as Eq. ( 4) [20], where γ 0 = n sw √ ε 0 µ 0 and γ S = n PD √ ε 0 µ 0 are transmittance parameters, n sw denote the refractive index of the seawater [21], n PD denotes the refractive index of the photo-detector input aperture [20], ε 0 is the permittivity of free space, and µ 0 denotes the permeability of free space.…”

“…Nevertheless, a few studies have considered such dependence. For instance, in a recent study [12], the UOWC system performance was studied incorporating the effect of multipath and the impact of wavelength. Simulation results with variable incident angles of both signal and background lights are provided.…”