为解决射频识别系统(RFID)因冲突频发造成识别效率低下的难题,采用正交码编译标签类别信息和相似原则结合的方法,提出了冲突容忍的快速识别机制UACP。基于沃尔什正交码信号良好的自相关性,将冲突信号与全集进行相关运算并与门限值比较,实现冲突容忍并准确识别;基于相似原则,仅利用单时隙与总时隙数目关系,从微观估测宏观以快速确定各类别现存状况。且算法针对多组正交码排列组合、非同步码偏移、信号丢失率、信号误判率等制约因子进行理论分析,结果表明在时隙利用率、识别速率、时间效率等性能指标上较传统算法有明显优势。采用BPSK调制及USRP平台实验验证该算法识别效率提升25%-60%。
To solve the low efficiency caused by the collision in Radio Frequency Identification System (RFID) , a collision tolerance mechanism UACP is proposed to identify tags quickly, exploiting the fusion method between orthogonal code compiling category ID and analogy principle. Based on the Walsh code autocorrelation feature, UACP made a correlation value comparison with the threshold between the collision and the whole set to realize the tolerance and accurate identification UACP estimated the existing number from microcosmic to macrocosmic only using the quantitative relation between the singleton and the whole slots. UACP analyzed the factors that the permutation and combination of multiple sets orthogonal codes, asynchronous code offset, signal missing rate,signal misjudgment probability, and shown the advantages on slot utilization rate, identification rate and time efficiency. Adopting BPSK modulation and USRP platform, UACP presented 25% to 60% improvement on time-efficiency.