Analytical model for optical wireless OFDM system with digital signal restoration

An analytical model for performance evaluation of the optical wireless communication (OWC) system employing orthogonal frequency division multiplexing (OFDM) with deliberate signal clipping and digital signal restoration is developed. The deliberate digital baseband clipping is introduced in the system transmitter in order to reduce a high peak-to-average power ratio (PAPR) of the OFDM signal and achieve an optimum modulation index of the intensity-modulated (IM) optical signal. In the system receiver a post-detection digital signal restoration is applied in an iterative manner in order to compensate for the effect of clipping noise and improve the system performance. It is emphasized that at the operation of decoding in the process of iterative signal restoration the main mechanism limiting the system performance at small clipping levels of the signal is introduced.