On the Performance of Biologically-Inspired Slot Synchronization in Multicarrier Ad Hoc Networks

Decentralized slot synchronization protocols inspired from nature have recently gained considerable interest. By adjusting the internal time reference of a node in response to the detected timing of a received synchronization word, and by following simple rules, synchronization emerges from an initially completely uncoordinated situation. However these protocols typically assume that synchronization words are detected error free. In this paper the performance of biologically inspired slot synchronization is investigated when a realistic timing synchronization scheme is employed. We consider an ad hoc network where nodes communicate over an orthogonal frequency-division multiplexing (OFDM) air interface. The transmission is organized in frames, and each frame is preceded by a synchronization preamble with known repetitive parts. Specifically one common synchronization preamble is employed for all transmitting terminals, as, e.g., for the wireless LAN standard 802.11. Computer simulations verify that provided a sufficiently long synchronization word, reliable slot synchronization is maintained using a practical synchronization unit.