Wireless LXI Bus Clock Synchronization and Triggering Design

In this paper, a wireless local area network (WLAN) extension for instrumentation (LXI) [WLXI] bus combining the technology of WLAN and LXI bus is proposed. Several different kinds of methods are designed to implement clock synchronization and triggering. For clock synchronization, a method using the IEEE 1588 protocol based on extended Kalman filter (EKF) is introduced as emphasis. For this method, the wireless IEEE 1588 protocol is used as a communication protocol of clock synchronization, and EKF is used to resolve the clock´s nonlinear shifting. The EKF improves the precision of clock synchronization, thus, high-precision clock synchronization for WLXI is realized. For triggering, a method based on the direct-sequence (DS) ultrawideband (UWB) is introduced and emphasized. For this method, DS spread-spectrum (DSSS) UWB is used as a modulation mode, combined with “lagging delay” wireless triggering to realize high-precision synchronization triggering for WLXI.