The Research On The Cycle Prefix In The All Optical OFDM Based On The After Postion Sampling Method

As the rapid development of voice and video business, orthogonal frequency division multiplexing technique has expanded the application fields. Optical orthogonal frequency division multiplexing technique, with the characteristics of high spectrum efficiency and excellent chromatic dispersion residence, become the research hot spot. It is difficult to adding the circle prefix in the optical orthogonal frequency division multiplexing system. Our research direction is the method of adding the circle prefix, which can improve the performance of optical orthogonal frequency division multiplexing system. The main work in the paper as follows:Firstly, after the studying of all kinds of OFDM systems, a novel method of adding the circle prefix in the all-optical OFDM system is proposed. The method is call post position sampling method, which can be realized easily and efficiently.Secondly, the all-optical OFDM system, using the proposed method, is demonstrated in the theory. The key modules of the system are studied detaily, including the all optical FFT module, optical time gate module, and optical phase shifter module.Finally, numerical simulation is carried out to investigate the performance of our proposed system. Results show that the circle prefix which has arbitrary length can increase the quality of received eye diagram and improve the dispersion tolerance. The power equalization has been used to eliminate the performance differences of channels.