A novel CD compensation scheme using differential pre-coding in CO-OFDM system

In CO-OFDM system, chromatic dispersion (CD) makes a great impact on the optical signal. The traditional way to compensate CD needs more overhead and high complexity of calculating. We propose a novel method to compensate CD phase noise using symmetrical pre-coding to the differential encoding symbols mapped from original bits, to ensure that every two adjacent symbols get the same CD phase noise. This symmetry will be used at the receiver to accomplish CD compensation. Compared with the traditional way of CD compensation, this scheme needs less overhead and the calculating complexity of the receiver is lower. We have verified that this scheme can compensate CD phase noise effectively by simulation.