Abstract:

This paper studies non-data-aided joint synchronization for orthogonal frequency division multiplexing (OFDM) systems, and a low complexity non-data-aided joint sampling frequency, symbol timing and carrier frequency synchronization algorithm is proposed based on time-delay correlation of received time -domain- OFDM signals. From the property of time-delay correlation that the period of time-delay correlation is the OFDM symbol rate, the period marker of the proposed algorithm is firstly obtained from the inherit property of cyclic prefix based OFDM. Then sampling frequency offset (SFO) could be estimated by comparing the received samples number with transmitted samples number in the same time, and the OFDM symbol start time and carrier-frequency- offset (CFO) could be estimated from the averaging result of the amplitude of time-delay correlation in subsection. Finally, the performance of the proposed algorithm is evaluated by computer simulation, and the simulation results show that the performance of the proposed algorithm is mainly affected by the cumulate time and  cyclic prefix (CP) length, and less affected by the modulation type of OFDM subcarrier. The proposed algorithm has lower implementation complexity and better performance compared with many other similar algorithms.