Localization has many important applications in wireless sensor networks, such as object searching and tracking, remote navigation, location based routing etc. The distance measurements have been based on a variety of...Localization has many important applications in wireless sensor networks, such as object searching and tracking, remote navigation, location based routing etc. The distance measurements have been based on a variety of technologies, such as acoustic, infrared, and UWB (ultra-wide band) media for localization pur-poses. In this paper, we propose UWB-based communication protocols for distance estimation and location calculation, namely a new UWB coding method, called U-BOTH (UWB based on Orthogonal Variable Spreading Factor and Time Hopping), an ALOHA-type channel access method and a message exchange protocol to collect location information. U-BOTH is based on IEEE 802.15.4a that was designed for WPANs (wireless personal area networks) using the UWB technology. We place our system in coal mine environ-ments, and derive the corresponding UWB path loss model in order to apply the maximum likelihood esti-mation (MLE) method to compute the distances to the reference sensors using the RSSI information, and to estimate the coordinate of the moving sensor using least squares (LS) method. The performance of the sys-tem is validated using theoretic analysis and simulations. Results show that U-BOTH transmission technique can effectively reduce the bit error rate under the path loss model, and the corresponding ranging and local-ization algorithms can accurately compute moving object locations in coal mine environments.展开更多
TD-LTE(time division-long term evolution)无线资源管理一致性测试是检验TD-LTE终端是否符合协议标准的重要手段。鉴于传统一致性测试平台存在不足之处,无线资源管理一致性测试搭建了基于TTCN-3(testing and test control notation ve...TD-LTE(time division-long term evolution)无线资源管理一致性测试是检验TD-LTE终端是否符合协议标准的重要手段。鉴于传统一致性测试平台存在不足之处,无线资源管理一致性测试搭建了基于TTCN-3(testing and test control notation version 3)的一致性测试平台,并分析了该测试平台相对于传统测试平台的优越性。利用TTCN-3软件编写测试例并进行测试。通过分析测试流程图可以得出,一致性测试平台的可行性,并验证了该平台相对于传统平台的优越性。展开更多
文摘Localization has many important applications in wireless sensor networks, such as object searching and tracking, remote navigation, location based routing etc. The distance measurements have been based on a variety of technologies, such as acoustic, infrared, and UWB (ultra-wide band) media for localization pur-poses. In this paper, we propose UWB-based communication protocols for distance estimation and location calculation, namely a new UWB coding method, called U-BOTH (UWB based on Orthogonal Variable Spreading Factor and Time Hopping), an ALOHA-type channel access method and a message exchange protocol to collect location information. U-BOTH is based on IEEE 802.15.4a that was designed for WPANs (wireless personal area networks) using the UWB technology. We place our system in coal mine environ-ments, and derive the corresponding UWB path loss model in order to apply the maximum likelihood esti-mation (MLE) method to compute the distances to the reference sensors using the RSSI information, and to estimate the coordinate of the moving sensor using least squares (LS) method. The performance of the sys-tem is validated using theoretic analysis and simulations. Results show that U-BOTH transmission technique can effectively reduce the bit error rate under the path loss model, and the corresponding ranging and local-ization algorithms can accurately compute moving object locations in coal mine environments.
文摘TD-LTE(time division-long term evolution)无线资源管理一致性测试是检验TD-LTE终端是否符合协议标准的重要手段。鉴于传统一致性测试平台存在不足之处,无线资源管理一致性测试搭建了基于TTCN-3(testing and test control notation version 3)的一致性测试平台,并分析了该测试平台相对于传统测试平台的优越性。利用TTCN-3软件编写测试例并进行测试。通过分析测试流程图可以得出,一致性测试平台的可行性,并验证了该平台相对于传统平台的优越性。
