Research On Node Localization For Wireless Sensor Networks Based On DV-HOP Algorithm

Recent years, with the continuous development of high and new technology, multi-disciplinary fields become the focus of research. MEMS, wireless communication, the embedded system and sensor technology development and mature, promote the emergence and development of the wireless sensor network. Wireless sensor network combines many advanced technologies such as embedded computing technology, microelectronic technology, wireless communication technology, modern network and distributed information processing. It is the result of the merging of traditional disciplines and IT and is a brand new direction of development in the field of information science and it has very broad application, and it prospects in international attention.Wireless sensor network can monitor and sense and gather information on a variety of environments and objects (such as temperature, humidity, pressure, etc.) in the monitoring field. Then the network can process the collected data and sent them to the users or researchers wirelessly. However, the data collected by the sensor node must be combined with its location information makes sense, only people who know the location of the sensor nodes can analysis and process the incidents reported, and on this basis for further optimization of the network. Node location technology is one of the main support technology for wireless sensor network, it is meaningful that sensor nodes collect data must be combined with its location information. Only when we know the position of sensor nodes, can we analyze and process the data reported by the sensor nodes, so as to do further optimization. Therefore, scholars study in-depth with localization algorithm, and now there have been many localization algorithms for wireless sensor networks.Usually, according to whether measure the actual distance between the nodes in positioning process, localization algorithm can be divided into:distance related (Range-based) localization algorithm and distance irrelevant (Range-free) localization algorithm. The Range-free localization algorithm is currently one of the emphasis of research, because of low cost, location algorithm position accuracy can basically meet the practical needs, and have very big development perspective. In the range-free localization algorithm, the most widely used is DV-HOP algorithm, because it does not require node itself have distance measurement or Angle measurement function and also do not need extra angle or distance measuring device.An improved DV-HOP localization algorithm is proposed in the paper, aiming at the traditional DV-HOP localization algorithm. There will be a great error that using the nearest anchor node’s average hop distance instead of the average hop distance of all the anchor nodes that involved in the locating in the traditional DV-HOP localization algorithm. Therefore, the improved algorithm introduces threshold M, it uses the weighted average hop distances of anchor nodes within M hops to calculate the average hop distance of unknown nodes. In addition, the positioning results are corrected in the improved algorithm. The simulation results show that the improved localization algorithm effectively improves the positioning accuracy compared with the traditional DV-HOP localization algorithm, it is an effective localization algorithm in the wireless sensor networks.