Research And Implementation Of Key Technologies For Clock Synchronization In Wireless Indoor Distributed System Based On UWB

Wireless indoor distributed networks are widely used in indoor location services,smart cities and other fields.Wireless clock synchronization technology is a supporting technology for wireless networks to complete tasks such as target positioning and data aggregation.As the network deployment area is wider and tasks are more complex,the requirements for wireless network clock synchronization performance are becoming higher and higher.At present,mainstream wireless clock synchronization technology is difficult to meet increasingly stringent requirements in terms of synchronization accuracy and expandability.To solve this problem,this thesis proposes a distance aware wireless clock synchronization algorithm DAS(Distance Aware Synchronization)based on UWB(Ultra-wide Band).The main research contents and results of this article are:1.UWB technology is a communication technology that uses nanosecond short pulse modulation information.It has the characteristics of low power consumption,fast transmission rate and high time resolution.It is suitable for wireless networks with high performance requirements.This thesis proposes a wireless clock synchronization algorithm DAS that can accurately sense the distance between network nodes based on UWB.The DAS algorithm uses closed-loop feedback to achieve a good balance between synchronization accuracy and scalability.Finally,the algorithm parameters are set in terms of algorithm convergence speed.The simulation results show that compared with the clock synchronization algorithm in recent years,the DAS algorithm has excellent synchronization accuracy and scalability.2.In a complex environment,wireless network nodes will experience packet loss during communication,which will adversely affect wireless clock synchronization.This thesis introduces the Markov jump linear system model to model the DAS synchronization algorithm under packet loss,analyzes the synchronization accuracy and stability of the synchronization algorithm,and calculates the maximum tolerable packet loss rate of the DAS algorithm.In order to reduce the impact of packet loss,the Kalman filter is used to compensate for packet loss,which effectively improves the synchronization accuracy and reliability of the DAS algorithm in the case of packet loss.3.Designed and developed a UWB-based DAS wireless clock synchronization algorithm verification platform.The platform uses the UWB+ARM architecture,and conducted multiple sets of wireless clock synchronization experiments in single-hop and multi-hop networks.The test data shows that the DAS wireless clock synchronization algorithm based on UWB technology can accurately compensate for the deviation caused by the distance,achieve sub-nanosecond clock synchronization in a single-hop network,and significantly reduce the global synchronization error in a multi-hop network.The experimental results show that the UWB-based DAS synchronization algorithm successfully achieves the above performance and can meet different application requirements.