RFID多频点联合测距系统中的信号检测方法

主要研究射频识别(Radio Frequency Identification,RFID)多频点联合测距系统中如何检测标签反射信号以及如何提高信道估计精度的问题.首先,提出了一种标签反射信号的检测方法,利用标签反射信号的功率谱特性,通过分析接收信号的能量谱,识别标签反射信号得到识别信号,再利用能量检测方法对识别信号进行范围限制得到检测信号;然后,改进RFID的传统信道估计方法,以提高信道估计精度;最后,搭建了多频点联合测距系统以验证系统性能.实验结果表明,该系统具有较高的检测效率;经改进的信道估计方法能有效减小载波相位的方差;系统平均测距误差约为2.5 cm,实现了厘米级测距.

Signal detection in RFID multi-frequency joint ranging system

This paper discusses how to detect the tag reflection signal and how to improve the channel estimation accuracy in the radio frequency identification(RFID) multi-frequency joint ranging system.First,a detection method for tag reflection signals is proposed.According to the power spectrum characteristics of the tag reflection signal,by analyzing the energy spectrum of the received signal,the tag reflection signal is identified to obtain the identification signal,and then the energy detection method is used to limit the range of the identification signal to obtain the detection signal.Then,the traditional channel estimation method of RFID is modified to improve the accuracy of channel estimation.Finally,a multi-frequency joint ranging system is built to verify system performance.The experimental results show that the system has high detection efficiency,the improved channel estimation method can effectively reduce the variance of the carrier phase,the average ranging error of the system is about 2.5 cm,which achieves centimeter-level ranging.