Improved Preamble-Based Symbol Timing Synchronization Schemes for GFDM Systems

Generalized frequency division multiplexing (GFDM) is a flexible multicarrier modulation scheme and has been considered as a candidate for the physical layer of the 5G mobile communication system. The bit error rate performance of GFDM is affected by the symbol timing synchronization errors; however, the existing preamble-based symbol timing synchronization scheme for GFDM systems suffers from the timing-ambiguous plateau problem. In this paper, two improved preamble structures are constructed according to the characteristics of GFDM symbols to eliminate the timing-ambiguous plateau. The simulation results under AWGN and multipath fading channels show that the proposed autocorrelation timing synchronization schemes have better timing MSE performance compared to the existing preamble-based timing synchronization schemes.