|
Underwater Wireless Optical Communication (UWOC) represents an efficient and cost-effective mode of underwater communication, characterized by high data rates and low latency. As the carrier for underwater wireless communication, light waves are susceptible to the aquatic environment, experiencing scattering and absorption, thus limiting their transmission to very short distances. The primary objective of this paper is to extend the communication range and investigate the reliability of the design of underwater wireless optical links under high data rate conditions. The paper also seeks to refine the previous method of categorizing seawater environments into four types—pure, clear, coastal, and turbid—for setting light attenuation, by specifically adjusting key factors affecting the optical link such as the concentration of chlorophyll in seawater. This allows for a more accurate adaptation to the varying conditions of seawater in different regions. To significantly enhance system performance, Multiple-Input Multiple-Output (MIMO) configurations are employed to overcome the attenuation and turbulence effects in underwater channels. In terms of modulation, due to the superior performance of Orthogonal Frequency Division Multiplexing (OFDM) in underwater wireless optical communication, this paper adopts Direct-Detection Optical Orthogonal Frequency Division Multiplexing (DDO-OFDM) and concurrently employs Quadrature Amplitude Modulation (QAM). In addition to using DDO-OFDM and QAM, the paper utilizes the Optisystem software tool to design the system model proposed in this article. MATLAB components are incorporated to simulate the impact of chlorophyll in the aquatic environment and to conduct simulations and performance evaluations of Bit Error Rate (BER) and communication distance under varying MIMO conditions. The proposed system achieves a maximum distance of 55 meters for the 1 × 1 Single-Input Single-Output (SISO) configuration and extends up to 140 meters for the 4×4 MIMO configuration when BER is at 10-4. Under the BER of 10-6 , the maximum effective distance for the 1×1 SISO is 48 meters, while the 4×4 MIMO extends to 135 meters. The significant enhancement in effective communication range demonstrates the substantial performance improvement brought by MIMO, as well as its promising application prospects.
|
