The radio-over-fiber(ROF) network has been proved to the best candidate for the wireless-access technology, and the orthogonal frequency division multiplexing (OFDM) technique has been accepted as the core transmitting technology, so the OFDM-ROF sytem is the hot topic in the international academia. An OFDM-ROF system simulation model basing on IEEE 802.16a physical layer protocol had been built up. Special attention had been paid on the high peak-to-average power ratio (PAPR) of the OFDM signal which greatly constrained the performance of the OFDM-ROF system. A clipping and filtering technology had been investigated and simulated. Compared with the Naquist sampled, the two over sampled signal had a better performance in reducing PAPR. The bit error rate (BER) error flow research had been done with transmitting the clipped signal in nonlinear distorted ROF link. And the QAM had been testified for the preferred technique in OFDM-ROF link .