Design Of Wireless Location Node Based On CSS Platform

With the rapid development of communication technology and electronic technology, thewireless sensor network has been rapidly developed, and people pay more attention to itsbasic function of positioning technology. The demand for location-based information servicesin daily life is increasing. Undoubtedly, the most mature location-based services is GPSforthe time being, but the cost of GPS positioning system is too high, and which also does notmeet the design principles of the wireless sensor network. Therefore, a small range of precisepositioning was proposed based on wireless sensor network. Meanwhile, positioning functionis the premise of getting location of observation event and collection information, also thefoundation of other critical technology for wireless sensor network such as topology controland location routine.However, influenced by construction cost, complex indoor environments and algorithmrobustness and other factors and now there is not a perfect positioning technology program forthe indoor wireless positioning system. Various positioning systems have its system defectsand now it is still a study hotspot and difficulty to implement a robust and precise wirelesspositioning system oriented to complicated indoor condition. In this article comparisons areconducted betweenseveral wireless sensor network communication technology at home andabroad, such as UWB（Ultra-Wideband）, ZigBee, CSS (Chirp Spread Spectrum) and Wi-Fitechnology, and we found CSS technology is suitable for the development of a new positionnode, in both in communication distance or distance between measurement nodes.In this article, we adopt CSS technology to develop the NA5TR1wireless transceiverchip with which we design the wireless sensor network positioning system.in order to reducesystem construction cost and mobile node volume, we adopt NA5TR1chip and ATmega644Vto implement mobile node of system. In this article, for mobile node or reference node, weadopt power supply module and wireless communication module and digital processingmodule separate design method. Power supply module includes power supply and resetfunction; circuit board, which consists of wireless communication module and digitalprocessing module, has the function of adjusting connection and connection communication.Power supply module and wireless communication module and digital processing module canbe connected by switch on/off connection. Moreover, we also analyze reasons which causeerrors, and put forward new methods of revising. We improve CSS position node’spositioning accuracy by improving the accuracy of the measurement distance.In this article, we put forward three methods to revise distance. First, we adoptKALMAN filter way to solve system distance errors and get right distance value. Second, weadopt deviation estimated way to assess the measured deviation and take being them totalsystem output errors, to assess and get right value. Thirdly, we practice more for deviation in positioning system according to different distance value and different deviation, then getdifferent corrected deviation value, and revise these deviations to get right distance value. Inorder to test the function ofthe designed positioning system, we adopt CSS technology toconduct simulation experiment for positioning system in distance measurement betweennodes, and positioning accuracy. Final testing result show that designed positioned system cantrackthe mobile node within the sensor network.