Design And Research On Digital Baseband System Of RFID UHF Reader Based On GB/T 29768-2013 Standard

In recent years,with the development of computer communication technology and CMOS integrated circuit technology,RFID(Radio Frequency IDentification)has been widely used.RFID technology has many advantages.It has big data storage capacity,can read and write large distances and label data can be encrypted.which is widely used in the field of logistics,shopping malls,etc.,the Chinese government also attaches great importance to the development of RFID industry and in September 2013,released 800 / 900 MHz passive RFID "GB / T 29768-2013 information technology-radio frequency identification of 800 / 900 MHz air interface protocol",the new established national standard provides a convenient for the effective management of RFID industry,it is imminent to develop and design product in line with national standards.The main purpose of this paper is to design and research on the reader's digital baseband system comply with the new GB.Firstly,introduced the background and significance of the research,compared international standard ISO 18000-6c with the new national standard in digital baseband system,and analyze its differences,then research on the key module of the digital baseband system,and study the digital baseband system's anti-collision algorithm in-depth.Digital baseband system has two kinds of anti collision algorithms : deterministic and non deterministic.On the one hand,this paper proposes an improved algorithm based on the problem that the average number of query cycles is low and the total transmission time delay is large,the algorithm using the method of locking position of collision to discuss mapping table maximum number of value,compared collision number with the mapping table the size of the maximum number of digits,which in turn calls the appropriate mapping table,proposed grouping of thought,and specifies collision bit matching label all queries after again under a set of query operation,until all the tags queried.The algorithm is compared with backward binary search algorithm and anti-collision algorithm based on continuous collision bit mapping reduces the average query cycle,reduce the amount of transmitted information,so as to shorten the total transmission delay.On the other hand,study the probabilistic anti-collision algorithm in-depth and take a comprehensive simulation of ideal state of dynamic frame slotted ALOHA,the ISO / IEC 18000-6c's anti collision protocol based on Q value choice and the DDS-BT.The results show that the anti DDS-BT collision algorithm's throughput rate is obviously better than that of the two.Finally,test reader's digital baseband and RF part function realization separately,verify the communication's correctness in forward link and the back link.Test results show that,digital baseband part can complete data processing and information sending and receiving accurately.