Experimental study on the inverse GPS

记者是逆GPS定位系统的发明者之一。虽然逆GPS的原理正在逐渐被人们所认识，但很少有人进行实验。为了弄清系统实现及其定位性能的知识，对超声波和2.4 GHz无线信号进行了计算机仿真和实验；对于超声波实验，为了延长定位距离，进行了扩频超声波实验。结果表明，定位距离扩展了4倍，并对2.4 GHz无线电信号进行了仿真和实验。首先，通过使用载波级模拟器进行性能评估，得出系统建设的基本设计方针。同时，提出了一种改进的五根以上天线位置估计方法。其次，在考虑扩散的情况下，使用一种称为GIGA波的无线电通信模块进行了实验，这是一种通用设备。实验表明，大大提高接收符号恢复定时的精度是必要的。为了克服这一问题，本系统采用了CP-FSK。最后，通过调整导线长度，对虚拟三维空间的定位性能进行了评估。结果表明，该系统的定位精度为40 cm~90 cm，误差与GDOP具有相似的趋势。在无线电实验中，定位精度为80 cm~2m。未来的工作包括在各种无线电环境下的性能评估，以及明确所提出的方法在提高精度方面的效果。

This reporter is one of inventers of the inverse GPS positioning system. Although the principle of the Inverse GPS is being gradually recognized, few experiments have been carried out. To clarify the knowledge of system implementation and its positioning performance, computer simulations and some experiments for ultrasonic waves and 2.4GHz wireless signals were carried out.For ultrasonic experiments, to extend a positioning distance, experiments using spread spectrum ultrasonic waves were carried out. The results showed that the range of positioning distance was extended four times.For 2.4GHz radio signals, simulations and experiments were carried out. First, basic design policy for system construction was obtained by performance evaluation using the carrier-level simulator. And also, an improved method of position estimation using more than five antennas was proposed. Next, in consideration of diffusion, experiments using a radio communication module called "GIGA WAVE" that is general-purpose devices were carried out. The experiments showed that a great improvement of the accuracy of the reception symbol recovery timing was necessary. To overcome this problem, CP-FSK was adopted to this system. Finally, by adjusting of wire lengths, positioning performance in virtual 3-dimentional spaces was evaluated. The result showed that positioning accuracies were 40cm to 90cm, and errors and GDOP had similar tendencies of this system. And then, in radio experiments, positioning accuracies were 80cm to 2m.Future work includes performance evaluation in various radio environments, and making clear effects of the proposed method for improving precision.