Research On Energy Utilization And Communication Goodput In CRFID System

With the development of the industrial Internet of things(IoT)and the big data technology,the importance of the calculation quantity and the data volume is obviously increased.The services provided by traditional RFID technology can not meet the requirements of the application layer,so a new technology,Computational Radio Frequency Identification(CRFID),has arouse great concern to many scholars.The CRFID tag is a passive device integrating sensing and computing,communication and energy harvesting,which utilizes the Backscatter technology to obtain the energy in the UHF radio frequency signal sent by reader,so as to perceive sensor data and communicate with the reader.CRFID tags load highperformance MCU and a variety of sensors,which provide adequate guarantee for the computing and sensing ability of CRFID tag,but its power consumption increases greatly compared with the traditional RFID tags,and will affect the whole CRFID system communication performance,thus the energy shortage and low throughput problem of CRFID become the bottleneck of its development.In this paper,the research on the communication protocol is carried out,and the time slot selection mechanism of the inventory stage is redesigned to allow the tag to select the most suitable time slot,so that the tag transmit data according to its own energy state.The energy utilization efficiency of the CRFID tag is successfully improved,and the tag of the edge of the communication range is prevented from falling into the "power-down" dead cycle.In addition,during the access phase of communication,the main problem is low effective throughput in uplink bulk data transmission.This paper reduces the bit error rate by decomposing large packets into small packets,enables CRFID tags to quickly find the address of error data and re-transmit them through the design of data format.Thus the cost of data error re-transmission is reduced and the effective throughput of CRFID system is improved.On the other hand,this paper redesigns the hardware of the CRFID tag.By using the multi-impedance matching circuit,the multi-system amplitude modulation method is realized,the utilization efficiency of the frequency spectrum is improved,and the throughput of the CRFID tag is doubled.At the reader side,due to the passive nature of the CRFID tag,the problem of the impedance deviation of multi-system amplitude modulation can easily occur,so this paper provides a solution for decoding the multi-system amplitude modulation mode,the offset reflected signal sampling value is corrected by the Markov principle,and the success rate of the decoding of the reader is improved.Finally,this paper implemented the multi-digit amplitude modulation mode of CRFID tags on hardware,and verified the effectiveness and superiority of the optimized protocol through experiments.The experimental results show that the design of this paper significantly improved the energy utilization rate and effective throughput of CRFID tags.