Performance Evaluation of High Speed Coherent Optical OFDM System Using Wiener-Hammerstein Equalizer

摘要

This paper addresses OFDM (orthogonal frequency division multiplexing) transmission over optical links with high spectral efficiency, i.e. by using high-order QAM-modulation schemes as a mapping method prior to the OFDM multicarrier representation. Here we address especially coherent optical OFDM modem in long distance which is affected by nonlinear distortion caused by fiber nonlinearity. Fiber nonlinearity is a major performance-limiting factor in advanced optical communication systems. We proposed a nonlinear electrical equalization scheme based on the Wiener-Hammerstein model. To Compare with other popular linear compensation technique such as the LMS (least Mean Square), Volterra equalizer simulation results are presented to demonstrate the capability of a Wiener-Hammerstein model based electrical equalizer used in a coherent optical orthogonal frequency division multiplexing system. It is shown that the Wiener- Hammerstein model based equalizer can significantly reduce nonlinear distortion..