基于时间反演的室内精确单站定位技术研究

Research on Indoor Accurate Single Station Positioning Technology Based on Time Reversal

提出了一种基于时间反演和时域有限差分法的室内单站精确定位技术。该方法利用格林函数的对称性和电磁互易定理以及室内多次反射形成的复杂信道实现单站定位。首先,在实景中接收传感器记录下室内任意辐射源在接收点产生的场强信号,然后将该接收信号时间反演,在接收点进行辐射,此时在原辐射点形成信号的相关聚集峰值,根据峰值位置实现单站无源精确定位。后一步的时间反演过程,如果发射信号已知,可以通过相关运算来完成,如果信号形式未知,可以由时域有限差分法计算实现,无需构建真实的时间反演发射系统。仿真结果表明:该算法能够利用多径效应,在室内复杂障碍物环境下实现λ/12=8 cm的定位精度,在室外也可以对室内目标进行精确定位。

Based on time reversal and finite-difference time-domain method,an indoor single-station precise positioning technology is proposed in this paper.It utilizes the symmetry of Green function,the principle of electromagnetic reciprocity and the complex channel formed by indoor multiple reflections to realize the single station positioning.In the actual scene,the receiving sensor records the field strength generated by any indoor radiation source,and then inverts the time of the received signal,radiating at the receiving point.At this time,the relevant aggregation peak of the signal will be formed at the original radiation point.Accordingly,the passive precise positioning of the single station will be realized.The time inversion process of the latter step can be completed by correlation operation if the transmitting signal is known;otherwise,it can be calculated and realized by the finite-difference time-domain method,no need to build a real time inversion transmitting system.The simulation results show that the proposed algorithm can make use of the multi-path effect to achieve the positioning accuracy ofλ/12=8 cm in the indoor environment with complex obstacles,and can accurately locate indoor targets in the outdoor environment also.