Fig. 1. Schematic of the operating principle of the PDM CO-OFDM-OQAM system

Fig. 2. Flowchart of the proposed method

Fig. 3. Proposed pilot structure diagram of the dual-polarization states. (a) Training sequence; (b) frame structure

Fig. 4. Simulation configuration of the PDM CO-OFDM-OQAM system, the insets show its electrical and optical spectra

Fig. 5. PAPR performance of different channel estimation methods represented using complementary cumulative distribution function under the PDM CO-OFDM-OQAM system

Fig. 6. BER performance of different channel estimation methods in optical BtB scene

Fig. 7. BER performance of different channel estimation methods under SSMF transmission. (a) 100-km SSMF transmission;(b) 200-km SSMF transmission

Fig. 8. BER performance of the proposed method in a non-linear fiber channel