Performance Analysis of Pre-Distorted Layered Asymmetrically Clipped Optical Orthogonal Frequency Division Multiplexing.

Optical wireless communications (OWC) is considered as one of the potential technology in 6G, where pre-distorted layered asymmetrically clipped optical orthogonal frequency division multiplexing (PLACO-OFDM) has attracted much attention due to its advantages of reduced complexity and improved bit error ratio (BER). In this paper, we investigate the source of gain of PLACO-OFDM and compare it with LACO-OFDM, where the LACO-OFDM adopts a uniform subcarrier power allocation. After deriving the probability density function (PDF) and electrical power, we found that the operation of pre-distortion leads to an increase in transmitted total electrical power. The closed-form solution of power gain provides a basis for the evaluation of PLACO-OFDM performance and is then proved by simulations. On this basis, simulation results also show that PLACO-OFDM has a better BER compared to LACO-OFDM with uniform subcarrier power allocation. The performance of PLACO-OFDM is close to LACO-OFDM with uniform layer power allocation.