Performance Analysis of LDPC-Coded OFDM in Underwater Wireless Optical Communications

The performance of Low-Density Parity-Check (LDPC)-coded Orthogonal Frequency Division Multiplexing (OFDM) is investigated over turbulence channels in underwater wireless optical communications (UWOC). relation between the bit error ratio (BER) and parameters such as scintillation coefficient, signal-to-noise (SNR), length LDPC code, order OFDM quantified by simulation. Results show that while with subcarrier quadrature amplitude modulation (QAM-OFDM) has slightly better anti-turbulence than phase shift keying (PSK-OFDM), LDPC-coded QAM-OFDM a much PSK-OFDM, and, at SNR = 12, it decreases BER four orders magnitude compared to 16QAM-OFDM system when coefficient σξ2 0.05.