Research On Wireless Sensor Networks Node Localization Algorithm

Wireless sensor network (WSN) has the feature of low-cost, strong fault tolerance, and adaptation to various environments, so WSN has broad application prospects in the fields of environmental monitoring, military applications, smart home and etc. Wireless sensor network node location information acquisition technology is developed from independent simplification pattern to the integration, miniaturization and intelligent, networked, and it has become one of the most important and most basic technology in WSN.The research status of location algorithm of the wireless sensor networks at home and abroad introduced and the existing typical localization algorithm summarized firstly. TDOA localization algorithm has simple principle and the perfect ranging effects in the NLOS environments, needs no additional hardware facilities, so it is widely used in the location of wireless sensor nodes. Then the TDOA-based hybrid localization algorithm is presented after analyzing the advantages and disadvantages of a number of localization algorithms:combining the TDOA measurement distance data and the Chan algorithm, the initial coordinates is obtained, and then location error is controlled within a certain range by using a mathematical optimization algorithm combining the weighted-based least square method and iteration method.A wireless sensor network node localization algorithm based on hop-quantified (average virtual hop algorithm) proposed secondly. We know that the hop counts of the DV-HOP algorithm is an integer and same hop counts usually have different distance to the anchor nodes. The nodes with short distance to the anchor node will have larger area with the communication range of previous-hop and smaller area with the communication range of next-hop. So we design an algorithm to quantify the every step to real numbers and improve the location accuracy according to the actual distance. Then, the concept of adjacent sequence matching is presented, that is, the matching degree defined based on the RSSI information and estimated distance information, the nodes with larger localization error can be ruled out by comparing the matching degree.Finally, MATLAB simulation tool is used to simulate the location results and improved algorithm is evaluated by using the indicators of WSN node localization technology. It is shown that the performance of improved hybrid node localization algorithm is superior to other algorithms analyzed in this paper. Meanwhile, it is proved that the average virtual hop algorithm is better than the DV-HOP localization algorithm.