An improved novel joint channel estimation algorithm for the 112 Gbit/s PDM CO-OFDM system

In this paper, an improved novel joint channel estimation algorithm is proposed for the 112 Gbit/s PDM CO-OFDM system. This method combines the advantages of the intra-symbol frequency domain averaging (ISFA) method and the time domain averaging (TA) method, which can realize more accuracy channel estimation. Simulation results show that this proposal could promise a relatively stable performance even under a rapidly time varying environment. It significantly outperforms the ISFA method by 2.2 dB when the DGD equals 1000 ps, and has the advantages of 0.5 dB over ISFA in considering the laser linewidth and frequency offset.