超高频无源RFID系统中Capture效应建模与分析

摘要

针对超高频无源射频识别(RFID)系统中 Capture效应的分析问题,提出一种新颖的Capture模型-RFIDCap,并通过Monte-Carlo仿真分析了各系统参数对Capture效应的影响,同时比较了RFIDCap及其他传统模型与测试结果的符合程度.RFIDCap综合考虑了读写器抗干扰能力、无线信道损耗及衰落、标签反向散射等因素.仿真结果表明,读写器capture阈值、碰撞标签数量及标签位置是影响capture概率的主要因素.测试结果表明,实测数据与RFIDCap仿真值的均方误差小于3%,相对传统模型(均方误差大于12%)有较大幅度的改善.%Capture effect plays an important role in system performance evaluation and efficient anti-collision algorithm development in passive UHF RFID systems. In this paper, a novel RFID capture model-RHDCap is presented, which considers the anti-interference performance of RFID reader, path loss and Rician fading of indoor radio channel, backscattering and spatial distribution of passive tags. Dependence of system parameters on capture probability is analyzed by Monte-Carlo simulation. The results show that the capture ratio, collision size and TR( Tag-Reader) distance are the main influence factors for capture probability. Experimental results measured at a warehouse show that the mean square error between simulation results from RFIDCap and measurement data is less than 3% , which is much smaller than that as in traditional RFID capture models.