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Research On Rssi-based Ranging And Localization Technique For Wsn

Posted on:2011-06-12Degree:MasterType:Thesis
Country:ChinaCandidate:D K ZhuFull Text:PDF
GTID:2198330338489843Subject:Control Science and Engineering
Abstract/Summary:PDF Full Text Request
As a new type of wireless ad hoc network, wireless sensor networks have wide applications including military, industry, agriculture, environmental observation and collecting information in disaster areas. Knowledge of nodes'location is an essential requirement for many applications. Without location information of sensor nodes, the sensed data or the detection of events is nonsense. Therefore, localization for wireless sensor networks has been presented and studied. Based on the key characters of wireless sensor networks and the limitations of current research, this thesis focuses on RSSI-ranging technique and the localization issues related.There are two stages in the localization algorithm which is proposed in this thesis: the ranging stage and the localization stage . During the ranging period, the RSSI-ranging system is designed based on TinyOS and nesC language, and some experiments were done with IRIS nodes which are provided by Crossbow.After analyzing the chatacter of RSSI, the RSSI dispersion-weighted ranging technique is proposed and the math model about the RSSI-dispersion weighted ranging is achieved from the shadowing model. The experiment shows that the RSSI dispersion-weighted ranging technique is effective.During the localization period, after analyzing the model of ranging measurement based on RSSI, to make up for the deficiencies of Taylor series expansion-based localization algorithm, the Taylor series expansion-based localization algorithm was improved. Combined with the characteristics of the RSSI-based ranging measurement, the new algorithm uses weight coefficient to evaluate the ranging error's influence on the modifying addition of the estimation position, making the modifying addition more reasonable. The experiments show that the improved Taylor series expansion-based localization algorithm has higher accuracy than the former method and it basically meets the application's need. At last, the thesis analyses the effect on the localization caused by the anchor nodes'density and the anchor nodes'position.
Keywords/Search Tags:WSN, RSSI-ranging, Localization, TinyOS
PDF Full Text Request
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