A Novel Hierarchical Low Complexity Synchronization Method for OFDM Systems

Abstract

International audienceA new hierarchical synchronization method is proposed for initial timing synchronization in orthogonal frequency- division multiplexing (OFDM) systems. Based on the proposal of new training symbol, a threshold based timing metric is designed for accurate estimation of start of OFDM symbol in a frequency selective channel. Threshold is defined in terms of noise distributions and false alarm, which makes it independent of type of channel it is applied. Frequency offset estimation is also done for the proposed training symbol. The performance of the proposed timing metric is evaluated using simulation results. The proposed method achieves low mean squared error (MSE) in timing offset estimation at five(5 x) times lower computational complexity compared to cross-correlation based method in a frequency selective channel. It is also computationally efficient compared to hybrid approaches for OFDM timing synchronization

Timing and carrier synchronization in wireless communication systems: a survey and classification of research in the last 5 years

“…sel. Yes No Pilot Est Both No [147], [156], [177] Freq. The papers here can be grouped into two categories.…”

“…The differences among them are that in addition to joint timing and carrier synchronization, CFO estimation in [131] applies to a wide CFO range, i.e., ±1/2 the total number of subcarriers width, [141] considers phase noise (PN)-sequence based preamble, [161] considers digital video broadcasting (DVB-T2) system, and [172] considers blind cyclic prefix length in their algorithm. The second group of papers provides an estimation error lower bound [147,156,177]. In addition to joint timing and carrier synchronization, [147] considers doubly selective channel, [156] considers hexagonal multi-carrier transmission system, and [177] proposes training sequence design.…”

“…The second group of papers provides an estimation error lower bound [147,156,177]. In addition to joint timing and carrier synchronization, [147] considers doubly selective channel, [156] considers hexagonal multi-carrier transmission system, and [177] proposes training sequence design. 4) Summary: Timing and carrier synchronization for multicarrier SISO communication systems is still an ongoing topic of research, as evidenced by the large number of published papers.…”

“…The second group of papers provides an estimation error lower bound [147,156,177]. In addition to joint timing and carrier synchronization, [147] considers doubly selective channel, [156] considers hexagonal multi-carrier transmission system, and [177] proposes training sequence design.…”