为减小短距离定位的复杂度,基于能量检测等非相关方法的波达时间(TOA)估计成为超宽带定位研究的热点领域。但当前方法仍须基于次Nyquist采样,即使采用帧或符号速率采样,也需要高精度步进搜索。借鉴锁相环频率综合器中取样锁相环原理,采用脉冲锁相环实现对超宽带脉冲信号的捕获,实现定位测距。由于在超宽带信号条件下,锁相环具有很高的干扰抑制作用,可以在极低信噪比下获得很低的TOA均方误差。在定位接收机实现中,利用了低复杂度的集成低频锁相环实现了定位测距功能。通过计算机仿真分析和电路实验表明该方法可靠性高,对硬件性能要求低,电路实现简单,易于集成化。
In order to reduce the complexity of short-range positioning ,energy-based detection algorithm and other non-coherent TOA estimation algorithms become UWB positioning research hotspot was proposed. However, those algorithms still based on Sub-Nyquist Sampling, even with the frame or symbol rate sampling, it also requires high-precision stepping Search. According to sampling phase-locked loop theory. PLL was adopted to capture the ultra-wideband pulse signal. Under the condition of uhra-wideband signal.PLL has a strong anti-jamming capability, it can be obtained a low mean square error of TOA in very low SNR condition. In the Positioning Receiver, a low-frequency PLL was adopted, and achieve positing function. Simulation and circuit experiments show that the algorithms is very effective to UWB signal, and the circuit is easy to implement.