Design And Development Ot UWB High Density Indoor Precision Positioning System Based On TDMA

With the development of wireless communication technology,people's demand for location based services extends from outdoor to indoor.In recent years,a number of wireless positioning technologies such as wireless local area network technology(WLAN),radio frequency identification technology(RFID),ultra-wideband technology(UWB)have become major topics of discussion for many researchers.Among them,UWB technology has gained high attention because of its advantages of high transmission rate,strong anti-interference ability and high positioning accuracy.However,most of the research directions of UWB indoor positioning are focused on positioning algorithm,fusion of positioning technology and so on.Few studies have been done on high-density scenarios of nodes,such as logistics warehousing,chemical industry and other scenarios where a large number of people or objects need to be positioned.In the scenario with high-density of nodes,indoor positioning system faces the problem of link resource constraints If there is a lack of reasonable planning for link resources,it will lead to frequent collisions of signals in space and generate long delay,thus extremely affecting the positioning real-time and accuracy.Aiming at these problems,this paper designs and implements a high-density indoor precise positioning system of UWB based on TDMA using the idea of wireless sensor network.By dividing the time into slots,location nodes can transmit and receive data orderly in the slots,so that the positioning system can carry a large number of positioning nodes,and ensure the real-time and accuracy of positioning.Aiming at the problem that the positioning system can not adapt to the high density of nodes,this paper designs the following communication scheme for the MAC layer of the positioning system:Firstly,the link scheduling module is designed based on the TDMA protocol,including the design of superframe structure,the setting of time slots,the arrangement of time slots and the control of data sending and receiving.Through the above design,the positioning system can accommodate a large number of positioning nodes,and secondly This paper designs a network control management module,which is based on the link scheduling module.The module controls the nodes to complete synchronization,access and exit,so as to achieve the synchronization of the nodes in the system,achieve the goal of planning link resources and ensure real-time positioning.According to the design,this paper divides the protocol stack into MAC control sublayer and MAC scheduling sublayer.The MAC control sublayer provides control management services and data services.It is responsible for providing the upper application with receiving and transimission interfaces,managing and allocating frames and slots,and storing scheduling information.The MAC scheduling sublayer is mainly responsible for slot scheduling,controlling RF chips to transmit and receive data and analyzing data packets.The two sub-layers complete the related functions of the protocol stack together.In this paper,we test the functionality of the MAC protocol and analyze positioning system in high-density scenarios of nodes.The results show that the MAC layer protocol based on TDMA can support precise indoor positioning in high-density scenarios.