Wireless Positioning Research For Moving Target In Mine Underground

Because a lot of wireless communication technology (for instance WCDMA、WIFI、ZIGBEE、Bluetooth and so on) are affected by underground roadway and the face of complexand changeful environment, their communication performance is poor, this causes that the effectof wireless positioning of underground moving target is not ideal. In order to solve the problemthat the underground wireless network stability reliability caused by the underground wirelessnetwork stability reliability is poor, this paper combines the principles of smart antenna andWIFI communication network with smart antennas receiver as underground WIFI base station,which can effectively inhibit roadway multipath and non-line of sight effecting signalpropagation, increase DOA and TOA estimation precision. Meanwhile theoretically analyzingrelevant DOA and TOA estimation technology, and targeting to explore and construct theunderground wireless positioning related theoretical model and the underground wirelesspositioning algorithm, its specific research content is as follows:1. According to different roadways and the working face, signal propagation pathattenuation and reflection form are analyzed, the distribution model of covering the undergroundwireless network base station is established, a joint positioning model based on DOA and TOAon the basis are established.2. For limited heterogeneous variable space of underground lead to coherent interferencesource, the technology of based on DOA estimation of coherent is analyzed selectively, forwardsmoothing and forward and backward smoothing and Toeplitz algorithm are used to proceed thesolution of coherent processing, obtain high accuracy DOA estimation information, thesimulation analysis indicates that in DOA estimation of coherent sources interference, Toeplitzalgorithm compared with other solutions coherence technique has better estimation performance.3. The influence of underground multipath, non-line of sight and the network timesynchronization cause that delayed arrival time estimation deviation is bigger, so a maximumlikelihood TOA estimation of iterative algorithm is proposed, via fractional delay iterated tonarrow the estimation error, the simulation analysis indicates: using50search step length and50search step length can get higher accuracy of TOA estimation information.4. In order to eliminate the DOA and TOA ranging error and according to the principle ofsingle basic station positioning, the positioning method of based on Angle rate and singlereflection is proposed respectively, and their positioning performance is simulated. In view ofinfluence of distance measuring error caused by network time synchronization of underground,according to the principle of base station positioning improving the positioning algorithm of Chan algorithm and weighted correction are proposed, the simulation indicates that improvedChan algorithm compared with other algorithm has higher positioning effect, and should chooseclose from the mobile node and high estimation precision of base station joint location.