Pilot-aided sampling frequency offset estimation and compensation using DSP technique in DD-OOFDM systems

• A sampling frequency offset estimation and compensation scheme for the DD-OOFDM system is experimentally demonstrated.
• The SFO-caused non-symmetric effect on the performance of the DD-OOFDM system is analyzed.
• The scheme can estimate and compensate SFO over a wide range without the sampling clock synchronization in the receiver.

To improve the outage performance of an optical orthogonal frequency-division multiplexing (OFDM) system under the frequency offset between the sampling clocks in the transmitter and receiver, a pilot-aided sampling frequency offset (SFO) estimation and compensation scheme for the optical OFDM system with intensity-modulation and direct-detection (DD-OOFDM) is experimentally demonstrated. The experimental and simulated results show that the scheme can work effectively even with large sampling frequency offsets. In addition, it can achieve a good bit error rate (BER) performance without the sampling clock frequency synchronization in the receiver.