Performance Evaluation of an OFDM-based Underwater Wireless Optical Communication Link by Considering Depth-Dependent Variations in Attenuation

Abstract

This paper investigates the performance of a 10-meter length Orthogonal Frequency Division Multiplexing (OFDM)-based Underwater Wireless Optical Communications (UWOC) link by employing quadrature amplitude modulation (QAM)scheme for various depths, taking into account impact of the depth variation on the attenuation coefficient in the clear open ocean. The channel is simulated through the Monte Carlo modeling of light (MCML) method using the Henyey-Greenstein model of the scattering phase function. A least-square (LS) channel estimation method has been used for equalization whose coefficients are obtained using a comb type channel estimation (CE) arrangement and interpolation. The results show that increasing of depth has a significant effect on Bit Error Rate (BER) performance as the BER reaches from 5.25⨯10−6at a depth of 1 m to 1.21⨯10−2 at a depth of 30 m. Also, the intensity of the received light decreases by increasing depth water and distance between the transmitter and receiver.