Study Of RFID Reader Anti-collision Algorithm For Dense RFID System (DPC-EDiCa-a Novel Algorithm Proposed And Studied)

Radio Frequency Identification (RFID) is a kind of untouchable automatic identification technology. RFID Anti-collision Technique is one of the critical techniques to RFID technology. In General, researchs of RFID anti-collision could be simply divided into two directions, which are anti-collision for multi-tags and anti-collision for multi-readers. To dense RFID system, it is impractical to only rely on the technique of anti-collision for multi-tags to increase the efficiency or to solve all collision problems. In some application scenarios, it always needs to install a bunch of RFID readers allover the space to cover enormous of tags that regarded as stocks.The collision problem would become worse as the number of readers rises, or the increase of the tags'number. Fortunately, RFID reader has satisfactory computing resources and communicating abilities to handle complex computing jobs. Moreover, for the good to deployment of multi-tags anti-collision technique, employing the reader anti-collision technique among RFID reader networks to eliminate kinds of collision phenomenon is the first thing to do. Therefore, multi-readers anti-collision technique becomes our research direction.In general, these reader anti-collision algorithms could be classified into tow types, coverage-based and scheduling-based. At present, most of the RFID reader anti-collision algorithms limit themselves in a particular methodology, for instance the distributed power control algorithms are seldom to be enhanced by artificial intelligent strategy; rarely research of the crossing application of scheduling-based algorithms and power control algorithms appears. Our work tries to work on the combination algorithms, which combining the power control methodology, LBT mechanism and a scheduling-based algorithm - EDiCa. The novel anti-collision algorithm is named, DPC-EDiCa. The implementation of this algorithm, on one hand, applys the Distributed Power Control (DPC) technique, and on the other, applys double channel coordinating technique. This paper tries to discuss the aspects of both techniques and endeavor to the enhancement.On the DPC technique, this paper proposed an algorithm to handle the power adjusting problem, Er Fen Approaching Algorithm (EFAA). One of the excellent features of EFAA is it could finish the power adjusting process within foreseeable rounds, while other power adjusting schemes or power update schemes are always suffering to unknown rounds of the completion of power adjusting process.On double channel coordinating technique, this paper proposed an operable strategy to settle the size of coordinating range (also called control range): The coordinating range is approaching to the four times of reading range. Meanwhile, DPC-EDiCa algorithm now adds a new reader state, adjusting, into the original state scheme used in EDiCa algorithm, as there are three state (idle, reading, waiting) exsits in EDiCa reader state scheme. The consequence of this new state added the possible combination status of all reader states information that received from all neighbor raise upto 8 kinds. Therefore, this paper needs to carefully classify these 8 kinds of status and pointly designs 4 kinds of action schemes to them.Last but not least, some discussions on several academic problems of RFID reader anti-collision technique and simulation results to evaluate the efficiency of DPC-EDiCa algorithm are given in the last several chapter of this work. The energy efficiency of DPC-EDiCa is about at the same level of DiCa. The throughput of DPC-EDiCa is increase a lot comparing to EDiCa and DiCa. From the maximum throughput comparasion, when dense RFID System is deployed suitable, the throughput of the RFID sytem employed DPC-EDiCa algorithm appears much more satisfactory. Moreover, the minimum throughput comparasion shows that DPC-EDiCa could also gain higher throughput than EDiCa and DiCa even in the dense RFID system which is badly deployed.