Polarized Complex Modulation for Underwater Wireless Optical Communications

In this paper, we propose a polarized complex modulation (PolCM) scheme by combining polarized pulse shift keying (PolSK) and quad-LED complex modulation (QCM) for underwater wireless optical communications (UWOC). The proposed PolCM scheme utilizes two LEDs and two polarization directions to map real/imaginary part and positive/negative value of a complex data symbol which can be transmitted without Hermitian symmetry operation. Numerical results have validated the proposed PolCM scheme in terms of BER performance compared with Monte Carlo simulation and also demonstrated the system performance for various link distances and water types.