无线传感网络定位中利用游标效应的高精度RF传播时间测量方法(英文)

Novel high-precision RF time - of - flight measurement method based on vernier effect for localization of wireless sensor networks

无线传感网络中传感器节点的定位信息很重要,而精确的测距技术是获得传感器节点间可靠的距离信息所不可或缺的。在时钟系统中引入游标卡尺的原理,提出了高精度的RF飞行时间测量方法。2个异步时钟好像游标卡尺的主尺和副尺刻度一样,可以引出新的比原时钟频率高很多的虚拟时间分辨率。用2种异步时钟连续进行RF发射和接收,产生与RF信号传播时间有关的测量模式,由测量模式推测出RF传播时间。开发了短距离RF收发的实验系统,实验证明8 MHz的低分辨时钟系统可以测出12.5 ns的高分辨RF传播时间。

In wireless sensor networks （ WSNs）, the position of sensor nodes is one of the most fundamental pieces of information for completing the tasks given to the sensor nodes. Accurate ranging technique is indispensable to obtain the reliable distance value between sensor nodes needed for WSNs localization. Applying the principle of the vernier caliper to the clock system, this paper presents a novel high-precision RF time-of-flight （ToF） measurement method based on the vernier effect ; two heterogeneous clocks, which are similar to the two different scales of the vernier cali- per, are employed for inducing new virtual time resolution that is much finer than the intrinsic time resolution of the two heterogeneous clocks. The consecutive RF signal transmission and sensing using two heterogeneous clocks generate unique sensing patterns according to the amount of propagation time of the RF signal, so that it is possible to estimate RF ToF based on the measured sensing pattern. Short-range RF ToF measurement tests using a developed experimental device certify that it is possible for a low-precision clock system having a low operating frequency （ e. g. , 8MHz） to exactly measure RF ToF of several nanoseconds （e. g. , 12.5 ns） by means of evaluating the measured sensing patterns with respect to the RF ToF.