CAJ | 학술논문

提出一种种基于时间反转的室内多散射环境射频定位方法。不同于传统的对多径效应敏感的采用接收信号强度、到达时间估计、到达角估计的射频定位方法，时间反转方法充分利用了多径传输作为有用信息。该方法首先要求RFID标签发射一个定位脉冲，该脉冲经过环境散射与多径传播后被阵元间距为3倍波长的稀疏天线阵接收。利用电磁场数值计算方法在仿真空间内将接收到的信号进行时间反转并重新在接收天线阵元位置分别发射。由于室内环境分布（如房间、门等）可视为已知信息，利用该信息可在仿真空间内建立完整而准确的电磁波多径传播模型，用于反演时间反转定位脉冲信号的传播过程。为了估计目标的位置，给出了基于时间反转的反演估计算子。通过监测估计子或时空域电磁场能量分布，即可获得RFID所在位置。仿真结果证实了该方法的有效性，并且由于时间反转方法充分利用了多径传输过程，故在稀疏天线阵下同样有很好的定位性能。
제출일충충기우시간반전적실내다산사배경사빈정위방법。불동우전통적대다경효응민감적채용접수신호강도、도체시간고계、도체각고계적사빈정위방법，시간반전방법충분이용료다경전수작위유용신식。해방법수선요구RFID표첨발사일개정위맥충，해맥충경과배경산사여다경전파후피진원간거위3배파장적희소천선진접수。이용전자장수치계산방법재방진공간내장접수도적신호진행시간반전병중신재접수천선진원위치분별발사。유우실내배경분포（여방간、문등）가시위이지신식，이용해신식가재방진공간내건립완정이준학적전자파다경전파모형，용우반연시간반전정위맥충신호적전파과정。위료고계목표적위치，급출료기우시간반전적반연고계산자。통과감측고계자혹시공역전자장능량분포，즉가획득RFID소재위치。방진결과증실료해방법적유효성，병차유우시간반전방법충분이용료다경전수과정，고재희소천선진하동양유흔호적정위성능。
An indoor Time-Reversal (TR) Based RF locating method is proposed to locate a RFID tag in rich scattering environment. Unlike the conventional locating methods based on Received Signal Strength Indicator (RSSI), Time of Arrival (TOA), and Direction of Arrival (DOA) estimation which are sensitive to the multipath effects, TR method utilizes the multipath propagations as useful information. The proposed method first requests a RFID tag to emit a locating pulse, the scattered pulse is received by a sparse antenna array with 3 wavelengths spacing, and then the received signals are time-reversed and retransmitted in a simulation domain by using numerical electromagnetic calculation methods. Because the information of the environment (such as rooms, doors, et al) can be known in advance, the propagation paths of the pulse can be accurately reconstructed. In order to locate the RFID tag, a location estimator based on TR inversion is also given. By monitoring the output of this location estimator or the energy distribution in both time and spatial domains, the RFID tag can be located. This TR based RF locating method has great advantages over the traditional back-projection method because the multipath propagations in this rich scattering environment have been well utilized. Simulation results show the effectiveness of the proposed method. Furthermore, originating from the well utilization of multipath propagations, TR based method can still work very well for locating with this very sparse array.