An Optimization Algorithm Of Time Synchronization And Spatial Localization In WSN

With the development of wireless sensor network technology and LBS technology, the spatial location and time information has gradually become the two basic information that essential to the practical application of wireless sensor networks, how to localize and synchronize the nodes with high accuracy is a international popular subject, how to make localize algorithm and time synchronize algorithm in a tolerable power assumption and relatively high accuracy is a key point in the international research.Spatial localization and time synchronization in their respective fields are both developed maturely, therefore, the algorithm on international didn’t combine these two fields together into consideration. This subject combine these two algorithm together thus propose an algorithm which can improve both accuracy.Zigbee is characterized by low power assumption and low speed, it is very suitable for the actual application of wireless sensor node. In this project which based on ARM7 hardware Zigbee AODV network topology, a set of innovate algorithm that solute both spatial localization and time synchronization are proposed. At first, present a point estimation method after GPS data sampling thus eliminate the influence of errors caused by the GPS information. Secondly, select the anchor nodes through divide and conquer method to ensure the reliability. Route nodes can correct their topology through positioning with anchor nodes and calculate the probability distribution. Finally, a competitive mechanism is mentioned to coordinate the correction of the network topology of whole WSN. The actual test achieve the anticipated goal.Through the spatial positioning with high accuracy, the location information of sensor nodes are taken into the algorithm of time synchronization, this thesis proposed a multiple data transmission algorithm based on TS/MS protocol and the new algorithm doesn’t depend on the hierarchical network. Take the distance of different nodes into account greatly improve the accuracy of time synchronization algorithm.With the algorithm mentioned above, the accuracy of spatial localization and time synchronization can be improved a lot, making it possible to applied in actual application which high precision is required.