Abstract
Motivated by the robust immunity to interference as well as the higher spectrum efficiency, Orthogonal Frequency Division Multiplexing (OFDM) has been widely considered as one of the strongest contenders for high-speed Next-Generation Passive Optical Networks (NG-PONs), which satisfies the huge surge in demand for high-speed broadband services. In the other hand, OFDM systems suffer from a high Peak-to-Average Power Ratio (PAPR) at the transmitted signal resulting in signal degradation. The simplest method to deal with the PAPR problem consists in applying deliberate clipping to the transmitted signal which significantly reduces the requirement of the received optical power. In this paper, an analytical evaluation for the performance of an IM/DD optical OFDM system is shown, this is while accounting for clipping distortion and quantification noise caused by the limited bit resolution of DAC converter. Moreover, the paper demonstrates that applying digital signal restoration at the system receiver enables further improvements in the system performances in terms of enhanced effective Signal-to-Noise Ratio (SNR) and reduced optical power that is required to achieve specifiedBit-Error-Rate (BER).