The performance of a cellular location system based on received signal strength difference （RSSD） is investigated. In the cellular location system, each mobile station needs to measure the signal strength transmitte...The performance of a cellular location system based on received signal strength difference （RSSD） is investigated. In the cellular location system, each mobile station needs to measure the signal strength transmitted by surrounding base stations, and sends its measurements to the service base station. Using the strength difference between the service base station and neighboring base stations, the position of a mobile station is estimated. The related Cramer-Rao lower bound （CRLB） on the location error of this method was derived, and numerical simulations are made to discuss the influences of the number of base stations, correlation coefficient of shadowing attenuation, and cell radius on CRLB. The results show that the CRLB is positively correlated with the standard deviation of shadowing attenuation and cell radius, but negatively correlated with the number of base stations and the correlation coefficient of shadowing attenuation. In addition, the CRLB results obtained in this paper were compared with those of the cellular location system based on received signal strength （RSS） measurements, which reveals that the former is more tight.展开更多
随着社会和技术发展的需要,无线定位问题,无论室外定位还是室内定位,都越来越受到人们的重视,GPS定位系统在室外具有良好的性能,但由于建筑物遮挡,GPS不能进行室内定位,而且定位成本过高。射频识别（Radio Frequency Identification,RFI...随着社会和技术发展的需要,无线定位问题,无论室外定位还是室内定位,都越来越受到人们的重视,GPS定位系统在室外具有良好的性能,但由于建筑物遮挡,GPS不能进行室内定位,而且定位成本过高。射频识别（Radio Frequency Identification,RFID）应用于室内定位和小范围内低成本定位,表现出良好性能。RFID和其他技术相结合,例如：图论、树、模糊数学、概率论等,产生了很多相关的定位算法,该文主要论述了RFID定位问题及其与其他相关的技术结合形成的各种算法,并结合RSS与TDOA定位思想,提出一种新的定位思想,利用多个接入点接收到的RSS信号差值对目标物体进行定位,并讨论了WIFI网络和Ad-hoc等网络中的定位问题。展开更多
以基于轻型无人机平台的空基定位系统实施干扰查找为应用背景,对多平台到达时差定位(Time difference of arrival,TDOA)实现机理进行了深入分析。针对TDOA定位前无人机群快速抵达最佳定位区域,进而实现有效定位的问题,提出了一种基于接...以基于轻型无人机平台的空基定位系统实施干扰查找为应用背景,对多平台到达时差定位(Time difference of arrival,TDOA)实现机理进行了深入分析。针对TDOA定位前无人机群快速抵达最佳定位区域,进而实现有效定位的问题,提出了一种基于接收信号强度(Received signal strength,RSS)定位辅助信息的TDOA定位方法,详细描述了定位流程和关键场景。通过方法可行性论证和定位性能分析得出:该方法可在定位流程自动化实施顺利的前提下,使系统最长定位耗时控制在无人机的一个续航周期内。展开更多
基金The National Natural Science Foundationof China (No.60472089)Southwest Jiaotong University Young Stuff Startup Research Project (No.2007Q134)
文摘The performance of a cellular location system based on received signal strength difference （RSSD） is investigated. In the cellular location system, each mobile station needs to measure the signal strength transmitted by surrounding base stations, and sends its measurements to the service base station. Using the strength difference between the service base station and neighboring base stations, the position of a mobile station is estimated. The related Cramer-Rao lower bound （CRLB） on the location error of this method was derived, and numerical simulations are made to discuss the influences of the number of base stations, correlation coefficient of shadowing attenuation, and cell radius on CRLB. The results show that the CRLB is positively correlated with the standard deviation of shadowing attenuation and cell radius, but negatively correlated with the number of base stations and the correlation coefficient of shadowing attenuation. In addition, the CRLB results obtained in this paper were compared with those of the cellular location system based on received signal strength （RSS） measurements, which reveals that the former is more tight.
文摘针对基于智能手机的汽车无钥匙进入和启动系统(PEPS)车内外高精度辨识技术需求,设计基于双终端的差分K近邻定位算法.通过改进的Dempster-Shafer证据理论,将双终端算法与典型单终端算法的辨识结果进行融合,提升识别算法的鲁棒性与准确性.与传统的K近邻和概率分布法相比,融合算法在实验场景中对终端车内外状态的辨识准确率提升10%.在传统定位算法易出现误判的车窗附近范围内,将误差距离从距车窗20 cm缩小到距车窗5 cm.
文摘随着社会和技术发展的需要,无线定位问题,无论室外定位还是室内定位,都越来越受到人们的重视,GPS定位系统在室外具有良好的性能,但由于建筑物遮挡,GPS不能进行室内定位,而且定位成本过高。射频识别（Radio Frequency Identification,RFID）应用于室内定位和小范围内低成本定位,表现出良好性能。RFID和其他技术相结合,例如：图论、树、模糊数学、概率论等,产生了很多相关的定位算法,该文主要论述了RFID定位问题及其与其他相关的技术结合形成的各种算法,并结合RSS与TDOA定位思想,提出一种新的定位思想,利用多个接入点接收到的RSS信号差值对目标物体进行定位,并讨论了WIFI网络和Ad-hoc等网络中的定位问题。
文摘以基于轻型无人机平台的空基定位系统实施干扰查找为应用背景,对多平台到达时差定位(Time difference of arrival,TDOA)实现机理进行了深入分析。针对TDOA定位前无人机群快速抵达最佳定位区域,进而实现有效定位的问题,提出了一种基于接收信号强度(Received signal strength,RSS)定位辅助信息的TDOA定位方法,详细描述了定位流程和关键场景。通过方法可行性论证和定位性能分析得出:该方法可在定位流程自动化实施顺利的前提下,使系统最长定位耗时控制在无人机的一个续航周期内。
