Simulation And Synthesis Of VCD Digital Part In RFID System

RFID (Radio Frequency Identification)technology,along with its application increasing, it promote people to research this technology. One of the key questions of RFID is solve collision when multiple tags send messages at one time, how to reduce the time used become hotspot. At present the main algorithms of anti-collision is bitree algorithm and the improved algorithm of it, the time consumption is large,so how to improve the rate of solve collision, reduce the time consumption of collision is be more and more attention.RFID system working at high frequencies 13.56 MHz which defined in ISO/IEC15693, can pierce metal material and most materials, long read distance, it also can produce relatively homogeneous literacy area, the system has the anti-collision characteristics, data transmission faster than low-frequency tag. So in this thesis, our object is simulation of the high frequency 13.56MHz, VCD(Vicinity Couple Device) part use binary algorithm to realize tag identify. And also improved the binary search algorithm, then put forward a new algorithm which is called segmental search algorithm。Simulation result of Matlab show that the new algorithm can reduce time consumption of inventory process significantly when the tag number is larger than specific number with fixed segmental method.In addition, using hardware description language Verilog HDL, complete descry-ption the designed coding module, decoding module, collision detection module, coll-ision processing module, control module, and use the main state machine to select which module to work. After simulation verilog files then use Quartus software to sy-nthsis, get the logic unit information pins, etc. After successful synthsis, files be download to the FPGA board to realization and validation. Experimental proof that thesis complete digital part of reader which match standard ISO/IEC15693 and use binary search algorithm deal with collision, the reader can complete recognition tags, no leak, no fault, and the structure is simple, has practical value for subsequent research. It provides the basis for the study of closer to RFID technology.