Research On Node Ranging In Wireless Sensor Network

Wireless sensor network is a distributed sensor network,which forms a multi-hop self-organizing network by sensing and checking sensors in the outside world.It relies on signal transmission between nodes to realize information exchange.Wireless sensor network has broad application prospects in military application,intelligent transportation,medical health and environmental monitoring.But accurate node location is a prerequisite for wireless sensor network to provide location service applications.Ranging-based positioning requires measuring the distance between nodes,which is used to determine the location of an unknown node.Common ranging methods include received signal strength indication,time of arrival,time difference of arrival,and angle of arrival.The RSSI ranging method is simple,low cost,and easy to implement,which does not require additional hardware equipment.Therefore,the RSSI-based ranging algorithm is mainly studied.Firstly,the ranging algorithms in wireless sensor network are discussed,and the advantages and disadvantages of each algorithm are briefly analyzed.Focusing on the RSSI ranging algorithm,a ranging algorithm based on convolutional neural network is proposed.In order to reduce the fluctuation of RSSI signal caused by multipath effect and NLOS transmission in complex ranging environment,RSSI sample data are constructed by measuring RSSI signal multiple times.And then the RSSI sample data set is used as the input to train a convolution neural network.The real-time captured RSSI signals are extracted by this network to estimate the distance between nodes.The Simulation results show that the ranging algorithm based on CNN can effectively improve the ranging accuracy.Non-line of sight propagation is one of the main sources of error in ranging estimation.In order to reduce the ranging error,non-line-of-sight authentication needs to know the channel environment.In view of this,a classification algorithm based on CNN is proposed,which is used to classify the channel environment.Finally,an RSSI-based ranging platform is designed,which includes hardware system and software system.The hardware system implements the collection of RSSI data and establishes a data set;the software system processes the RSSI data to obtain an estimated distance value.