Performance Analysis for DCO-OFDM underwater visible light communication system

Applying DC-biased optical orthogonal frequency division multiplexing (DCO-OFDM) technology in underwater visible light communication (UVLC), systems can improve the underwater anti-interference ability and information transmission rate. However, the DCO-OFDM system has the problem of a high peak-to-average power ratio (PAPR), and the linear operating voltage range of the Light Emitting Diode (LED) is limited, which can cause severe signal distortion and degrade the communication performance of the system. Therefore, this paper proposes a joint PAPR suppression algorithm based on a Hadamard matrix-improved selective mapping algorithm and clipping method (H-SLM-Clipping) to address this issue. Firstly, the frequency domain signals are precoded using a Hadamard matrix to reduce the autocorrelation between the signals before adopting the SLM algorithm. Then, the signals selected through the SLM algorithm are clipped to minimize the nonlinear distortion caused by the LED. Simulation results show that the proposed joint algorithm performs better in reducing PAPR than the original algorithm.