An asymmetric scan time synchronization algorithm for TDMA directional antennas networks

Recent research results show that there are significant gains in throughput to be realized with directional transmission and directional reception compared with that using Omni- directional, however, no specific directional antennas system time synchronization algorithms are presented. In TDMA system, each node must be severe synchronization so as to allocate time slot, so time synchronization is the critical technology in the TDMA system. The traditional time synchronization approaches are difficult to achieve time synchronization due to the characters of directional antennas. In this paper we introduce an asymmetric scan time synchronization method without external clock founded on TDMA Directional antennas networks, the source of errors are analyzed in detail. In simulation based on OPNET verification, the proposed asymmetric scan time synchronization method without external clock to achieve nanosecond-level synchronization accuracy and supports time synchronization under the conditions of high-speed mobile. The results in this paper provide theoretical foundation for investigating the TDMA directional antenna networks frame structure, algorithms of time slot reservation and other protocol in the future.