Experimental Demonstration of 55-m / 2-Gbps Underwater Wireless Optical Communication Using SiPM Diversity Reception and Nonlinear Decision-Feedback Equalizer
Ningbo Research Institute, Zhejiang University, Ningbo, China
Ji Du
State Key Laboratory of Modern Optical Instrumentation, Centre for Optical and Electromagnetic Research, National Engineering Research Center for Optical Instruments, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
State Key Laboratory of Modern Optical Instrumentation, Centre for Optical and Electromagnetic Research, National Engineering Research Center for Optical Instruments, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
Ruilin Chen
State Key Laboratory of Modern Optical Instrumentation, Centre for Optical and Electromagnetic Research, National Engineering Research Center for Optical Instruments, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
Jiahan Tian
State Key Laboratory of Modern Optical Instrumentation, Centre for Optical and Electromagnetic Research, National Engineering Research Center for Optical Instruments, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
State Key Laboratory of Modern Optical Instrumentation, Centre for Optical and Electromagnetic Research, National Engineering Research Center for Optical Instruments, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou, China
Underwater wireless optical communication (UWOC) is considered as an enabling technology with a mass of potential applications. The silicon photomultiplier (SiPM) exhibits a bright prospect for UWOC thanks to the traits of low-light detection capability, low-voltage operation, and superior operability. However, the performance of the SiPM-based UWOC system is severely degraded by the dead-time caused nonlinear response. In this paper, to mitigate the dead-time induced nonlinear distortion and explore the achievable capacity of the newly developed SiPM, we propose and experimentally demonstrate a 55-m/2-Gbps UWOC system by virtue of SiPM diversity reception and nonlinear decision-feedback equalizer (NDFE). The performance of NDFE is superior to that of the conventional decision-feedback equalizer (DFE), and NDFE with a pruning factor of 5 declares similar performance as that without pruning strategy, while the number of the nonlinear equalizer can be reduced by ~31.8%. Significant performance improvement is also obtained by the proposed scheme under different turbidity waters. The measured data rate is pushed from 1 Gbps to 2 Gbps with a receiver sensitivity as low as −41.96 dBm, which to the best of our knowledge is the largest data rate ever achieved using the off-the-shelf SiPM among the reported UWOC works. In accordance with the receiver sensitivity and the model of optical propagation in the water channel, the maximum attainable distance/data rate is predicted to be 147 m/1 Gbps and 128 m/2 Gbps with the proposed scheme. The research results are promising for long-reach and high-speed UWOC.
