• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1925-1933
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• 2015

RFID based applications that combine radar techniques to obtain the location and the ID of a tag have widely been investigated. In this paper, we analyze a recently proposed RFID system that can extract the tag IDs and their velocities using signals transmitted from the tag attached moving objects and verify its performance. In the proposed system, a beacon transmits triggering signal at regular intervals into a monitoring area and the tag receiving the triggering signal backscatters the FMCW(frequency modulation continuous wave) signal modulated by the tag ID. The reader system demodulates this FMCW signal using predefined two reference signals to obtain not only the tag ID but its velocity. In this paper, we show that the proposed system works properly and analyze the degree of performance degradation in cases when the synchronization error between the transmitting signal and the reference signal occurs, and even when sampling rate is lowered for implementation purpose. Finally, the analytical results are verified by simulation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.7
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• pp.752-760
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• 2010

This paper investigates the performance of EPCglobal Generation-2(Gen-2) radio frequency identification(RFID) protocol under reader-to-reader interfering environments. We establish a modified discrete-time Markov chain(DTMC) model for the Gen-2 and accordingly obtain quantitative results of query success rate(QSR) and tag identification speed (TIS). Extensive simulations validate our theoretical analysis and demonstrate that the number of tags over 100 has little impact on the performance. TIS linearly decreases by 10 tags/sec/reader as the number of interfering readers increases. Our model for Gen-2 protocol is also useful to study the performance of other RFID protocols.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.563-566
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• 2008

In RFID system. when a variety of tags are present in the interrogation zone of a single reader at the same time, the system requires a multiple tag identification scheme that allows the reader to read data from the individual tags. Anti-collision algorithms required for the multiple tag identification are essential for the implementation of RFID system. This paper analyzed the performance of SFSA algorithm, which is easy to implement. According to the analytical results, the algorithm's performances are closely related with the number of tags and the frame size.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.413-420
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• 2006

In this thesis, a RFID baseband system is implemented based on the international standard ISO/IEC 18000-6 Type-B using FPCA, and also anti-collision algorithm is implemented to improve the system performance. We compares the performance of the proposed anti-collision algorithm with that binary tree algorithm and bit-by-bit algorithm, and also validated analytic results using OPNET simulation. The proposed algorithm for Type-B transmission protocol and collision prohibition was designed using ISE7.1i which is a FPGA design-tool of Xilinx and implemented with Spartan2 chip which is a FPGA device.

• Journal of the Korea Society for Simulation
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• v.17 no.4
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• pp.99-112
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• 2008

In the passive UHF (860-960MHz) RFID communications, which consists of a set of readers and tags, the readers normally interrogate the tag by using the backscatter mechanism. (i.e., tag response). In practical RFID environment, where multiple readers or tags exist; the interference causes collisions. This paper proposes a centralized arbitration scheme for avoiding the collision problems among multiple readers. The proposed centralized arbitration scheme is modeled in software environments, and is verified with simulation results. Simulated performance is focused on completion time, utilization and response time, and the simulation results show that our proposed scheme provides satisfactory performance grade.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7A
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• pp.669-681
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• 2010

In this paper, we analyze the active RFID system ISO/IEC 18000-7. In order to apply to USN, which consists active RFID tags and sensor nodes, we propose UWB-based Class 4 active RFID protocol using active RFID relay tag as relay AP. To compare the performance between the existing ISO/IEC 18000-7 system and the proposed system, we introduce sensitivity-based measurement of achieved coverage and system efficiency. Also, we analyze the performance of the proposed system and compare it with that of the existing system through MCL analysis and SLS analysis.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.11
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• pp.90-94
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• 2008

Recently, a great deal of research is focused on the printed electronics. One of their mainly concerned products is printed RFID tag. RFID technology has attracted researchers and enterprises as a promising method for automatic identification, and they are expected to replace conventional bar codes in inventory tracking and management. The key to successful RFID technology lies in developing low-cost RFID tags and the first step in applying printing technology to RFID systems is to replace antennas that are conventionally produced by etching copper or aluminum. However, due to the printing quality variations, errors, and lower conductivity, the performance of the printed RFID antennas is lower than that of antennas manufactured by conventional etching methods. In this paper, the effect of variations in the printing conditions on the antenna performance is investigated. Three levels for each condition parameter is assumed and effect on the resonant frequency are examined experimentally based on orthogonal array. The most serious factor that affects the resonant frequency of the antenna is the non-uniformity of the edge and the resonant frequency is found to be lower as the non-uniformity increases.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.1
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• pp.17-23
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• 2006

In recent years, RFID has received much attention because of spread usage in industrial applications including factory, material flow, logistics and defense areas. However, there is only CRC-16 for error detection in ISO/IEC 18000-6 Protocols prepared for 860-960 MHz RFID, high error rates are expected in cases of high level of security and noisy envirionment. In this paper, we propose a usage of convolution code as a method for satisfying the high level of security requirement and system error performance.'1'he signal control function is implemented in a microprocessor with RF modulation and the convolutional encoding and Viterbi decoding are implemented in an FPGA chip.'The frame error rates are measured with and without convolution coding under the channel conditions of line-of- sight and non line-of-sight, respectively.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.343-349
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• 2014

Many systems using RFID/USN were and are being developed. Some systems are used in practice and some are not. Generally, the main reasons not being used are: The prices of chips are too high considering the effects. The application domain is not appropriate for RFID/USN. So, various skills for higher sensing precision have been introduced like using multiple sensors and avoiding metals which deter sensings seriously. Now, it is time to evaluate systems which were developed using RFID/USN technology. However, no systematic approach has been made for the evaluation. In this paper, a framework using BSC is introduced for the evaluation of systems using RFID/USN. In this framework, some Critical Success Factors(CSF) are derived and some Key Performance Indices(KPI) are developed for each CSF.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1673-1677
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• 2008

This paper studies on the read rate of UHF-band RFID tag. An RFID tag antenna attached on the high permittivity surface will be detuned that results in deteriorating the read rate. In this study, we investigate that the electrical performance for the tag antenna is detuned due to the ceramic material and the read rate is radically improved after tuning the antenna.