Performance Of RFID System Research Articles

Performance Limit: Fuzzy Logic Based Anti-Collision Algorithm for Industrial Internet of Things Applications

Passive RFID has the advantages of rapid identification of multi-target objects and low implementation cost. It is the most critical technology in the Industrial Internet of Things information-gathering layer and is extensively applied in various industries, such as smart production, asset management, and monitoring. The signal collision caused by the communication between the reader/writer and tags sharing the same wireless channel has caused a series of problems, such as the reduction of the identification efficiency of the reader/writer and the increment of the missed reading rate, thus restricting the further development of RFID. At present, many hybrid anti-collision algorithms integrate the advantages of Aloha and TS algorithms to optimize RFID system performance, but these solutions also suffer from performance bottlenecks. In order to break through such performance bottleneck, based on the ISE-BS algorithm, we combined the sub-frame observation mechanism and the Q value adjustment strategy and proposed two hybrid anti-collision algorithms. The experimental results show that the two algorithms proposed in this paper have obvious advantages in system throughput, time efficiency and other metrics, surpassing existing UHF RFID anti-collision algorithms.

An Efficient Early Frame Breaking Strategy for RFID Tag Identification in Large-Scale Industrial Internet of Things

With the increase in the number of tags, an efficient approach of tag identification is becoming an urgent need in Industrial Internet of Things (IIoT). However, the identification performance of existing Aloha-based anticollision schemes is limited when the initial frame size is seriously mismatched with the actual tag population size. The performance will degrade further when IIoT is deployed in the error-prone channel environment. To optimize the identification performance of RFID system in an error-prone channel environment, we propose an efficient early frame breaking strategy based anticollision algorithm (EFB-ACA) with channel awareness. The EFB-ACA divides the whole tag identification process into two phases: convergence phase and identification phase. The function of convergence phase is to make the adjusted frame quickly converge to an appropriate size. The early frame breaking strategy is embedded in the convergence phase. Numerical results show that the proposed EFB-ACA algorithm outperforms the other methods on efficiency and stability in the error-prone channel. In addition, EFB-ACA algorithm also outperforms the other methods in the error-free channel.

A Novel Hybrid Tag Identification Protocol for Large-Scale RFID Systems

Radio frequency identification technology is one of the main technologies of Internet of Things (IoT). Through the transmission and reflection of wireless radio frequency signals, non-contact identification is realized, and multiple objects identification can be realized. However, when multiple tags communicate with a singleton reader simultaneously, collision will occur between the signals, which hinders the successful transmissions. To effectively avoid the tag collision problem and improve the reading performance of RFID systems, two advanced tag identification algorithms namely Adaptive M-ary tree slotted Aloha (AMTS) based on the characteristics of Aloha-based and Query tree-based algorithms are proposed. In AMTS, the reader firstly uses the framed slotted Aloha protocol to map the tag set to different time slots, and then identify the collided tags using binary search method based on collision factor or mapping table. Both performance analysis and extensive experimental results indicate that our proposed algorithms significantly outperforms most existing anti-collision approaches in tag dense RFID systems.

A Method to Improve Identification Performance of UHF RFID Systems

A Method to Improve Identification Performance of UHF RFID Systems

Deterministic Dual-stack Query Tree RFID tag anti-collision algorithm

Tag collision problems are a major issue affecting the performance of RFID systems. The probabilistic tag anti-collision algorithm has tag starvation and cannot identify some tags. This paper proposes a deterministic dual-stack query tree algorithm (DDQT). It successfully implements the anti-collision algorithm of tags by generating new query codes and tag identification functions. At the same time, the DDQT algorithm greatly saves memory space by adding a prefix code stack and a suffix code stack. The DDQT algorithm is simple, and there is no limit on the length of the electronic tag to be queried. Compared with the previous query-tree algorithms, the DDQT algorithm has obvious improvements in query comparison times, empty query times, and occupied memory space. It can effectively remove idle nodes, shorten recognition time and save memory resources, thus improving the speed and accuracy of label recognition to some extent.

Analysis and improvements of the pseudorandom number generation in passive UHF-RFID tags

Several works have been carried out in recent years aiming at improving the performance of RFID systems. Some proposals focus their attention on the communication protocol between the reader and passive tags, trying to avoid collisions or the capture effect during the identification process. Most of these works have a common factor: the required use of a pseudorandom number generator that has a great impact in the performance of the identification process. This paper analyzes the quality of the pseudorandom number generator in commercial passive UHF-RFID tags, to assess whether its outputs can be distinguished from truly random data. It then goes on to present a new mechanism that simplifies the generation of these numbers. A set of tests has been used to assess the randomness of the measured pseudorandom number sequences from commercial tags as well as the pseudorandom numbers obtained with the proposed method. This new method has then been implemented in a physical platform that emulates a real tag and its adequacy checked with commercial readers. The results thus obtained indicate that the proposed method generates valid pseudorandom number sequences while reducing the complexity and power consumption required for the tag. • The quality of pseudorandom number generation in passive RFID tags is analyzed. • A new mechanism for its generation is presented and tested. • The proposal simplifies the generation of pseudorandom numbers in passive RFID tags. • The complexity and power consumption of the tag are reduced employing this method.

Evaluation of 13.56 MHz RFID system performance considering communication distance between reader and tag

Evaluation of 13.56 MHz RFID system performance considering communication distance between reader and tag

Performance Analysis of Passive UHF RFID Systems Under Cascaded Fading Channels and Interference Effects

In this paper, the performance of monostatic and bistatic passive ultra high frequency radio frequency identification (UHF RFID) systems under the effects of cascaded fading channels and interference is studied. The performance metric used is tag detection probability defined as the probability that the instantaneous received power is higher than the reader's sensitivity. A closed-form expression of the detection probability is derived using cascaded forward and backscatter fading channels and the reader antennas orientation relative to the tag. Furthermore, the performance of passive UHF RFID systems under reader-to-tag interference caused by both the desired RFID signal and multiple RFID interferers is analyzed, and the effect of constructive and destructive interferences is examined. In addition, the maximum reading range in ideal, multipath fading, and interfering environments is presented. To the best of our knowledge, this is the first work that provides a 3-D performance analysis of the passive UHF RFID systems under cascaded fading channels. The obtained results are very useful for the design and optimization of passive UHF RFID systems from an RF physical channel point of view.

IGAA: An Efficient Optimization Technique for RFID Network Topology Design in Internet of Things

Most RFID applications in the Internet of Things (IoTs) use multiple readers to read the IDs of multiple tags and form the RFID network. In such a network, unguarded reader deployment may generate over-crowded readers, cause interferences and, as a result, increases the deployment cost while degrading tag detection. Seeing that desirable reader deployment is crucial for RFID system performance, this paper introduces an optimizationbased IGAA approach which outperforms existing RFID topology designs by turning up more favorable reader deployment and system performance. The new approach employs an advanced multi-objective fitness function and improved genetic annealing algorithms (GAA) to pursue a better RFID topology design. By involving an improved gene-stirring operation to help preserve good genes and locate optimal solutions for reader deployment, it is simple in operation but effective in practice. Experimental evaluation shows that when compared with related approaches, IGAA can yield better solution quality with less search time.

Range measurements of a High Frequency Radio Frequency Identification (HF RFID) system for registering feeding patterns of growing–finishing pigs

Monitoring the feeding pattern of a pig enables early detection of diseases and other problems. To monitor the individual feeding pattern of group-housed pigs, it has been suggested to equip the pigs with High Frequency Radio Frequency Identification (HF RFID) tags and the feeding trough with an antenna. The detection range of the HF RFID system is crucial to guarantee that all feeding pigs are detected without detecting the pigs located further from the feeder. The current study examines the factors that influence whether an antenna attached to a round feeding trough (such as those used in group housing of growing–finishing pigs) detects stationary HF RFID tags placed in various orientations and distances from the antenna. Four experiments were performed using a custom-built test set-up that allowed determining the RFID registrations for 70 tag positions, at seven distances from the antenna and for seven orientations of the tags in relation to the antenna. In the first experiment there was determined that which tag side is closest to the antenna had very little influence on the range of registration. The results of the second experiment revealed that all eight HF RFID antennas in the pig house performed similarly, with symmetry observed in their range of registration. In the third experiment the range of the HF RFID system was measured while accounting for tag, tag position and tag orientation, whilst the last experiment was designed to test the effect of interference between tags. Reproducibility between (the order of) the tags and the average agreement between five repetitions of all tests was very high. In total, the sensitivity was 51.0%, with a standard deviation of 43.1percentage point (pp). The specificity was 87.1% with a standard deviation of 19.4pp. It was concluded that the performance of the HF RFID system in terms of sensitivity and specificity of the range depends greatly on the height and orientation of the tags. This causes irregular gaps to appear between subsequent RFID registrations of a feeding pig. To improve the performance of the system in practice, it is suggested to adjust the height of the antenna to better match the size of the pigs and to develop algorithms and criteria to merge raw RFID registrations into relevant feeding variables for individual pigs.

The Design of Ceramic Minkowski Fractal Antenna

Antennas play an important role in RFID system. As one of the key technology of RFID, the antenna design decides the RFID system performance. This paper designed a ceramic Minkowski fractal antenna used in RFID system. It used Minkowski fractal structure as the radiation patch and the high performance ceramic material to reduce the antenna size, then improve it with rectangular joint structure in the antenna's ground plate. In this paper, the antenna performance are analyzed in the simulation, In this paper, the antenna performance are analyzed in the simulation, it discussed the thickness of the medium plate and the effect of dielectric constant on the performance of microstrip antenna, finally make antenna samples for testing. The simulation and test results show the antenna designed meet the requirement of RFID applications.

Wavelet Denoising Method for RF Signal

To reduce the noises in received RF signal and improve the performance of RFID system, a novelty denoising method of wavelet transform in RFID system was proposed in this paper. It analyzed wavelet transform method and FFT method,then introduced wavelet transform principle and wavelet coefficients threshold denoising method. According to the standard ISO18000-3,the RF signal at 13.56MHz was simulated using modulation toolbox in LabVIEW environment. At last, the RF signal with Gauss white noise together, was denoised by wavelet transform method and FFT method respectively. Simulation results showed that the wavelet transform denoising method has higher accuracy, better effect, compared with traditional FFT denoising method. The research on application of wavelet analysis in RF signal denoising is significant and practical. The wavelet analysis is applied to the field of virtual instrument, which can provide people with more accurate and convenient testing, and has good application prospects in engineering applications.

Extending birthday paradox theory to estimate the number of tags in RFID systems.

The main objective of Radio Frequency Identification systems is to provide fast identification for tagged objects. However, there is always a chance of collision, when tags transmit their data to the reader simultaneously. Collision is a time-consuming event that reduces the performance of RFID systems. Consequently, several anti-collision algorithms have been proposed in the literature. Dynamic Framed Slotted ALOHA (DFSA) is one of the most popular of these algorithms. DFSA dynamically modifies the frame size based on the number of tags. Since the real number of tags is unknown, it needs to be estimated. Therefore, an accurate tag estimation method has an important role in increasing the efficiency and overall performance of the tag identification process. In this paper, we propose a novel estimation technique for DFSA anti-collision algorithms that applies birthday paradox theory to estimate the number of tags accurately. The analytical discussion and simulation results prove that the proposed method increases the accuracy of tag estimation and, consequently, outperforms previous schemes.

The Research and Implementation of RFID Middleware Data Filtering Algorithm

RFID is an advanced non-contact automatic identification technology. It is widely used in location, real-time identification and tracking and it has become a hot topic in the field of research. A lot of redundant data and noise data greatly reduce the efficiency and performance of RFID system. This study puts forward a filtering algorithm based on dynamic adaptive time window. In order to ensure the sequence of acquainted RFID data correctly, the ordered filtering algorithm based on hash table is introduced. Experiments show that the improved filtering algorithm not only can effectively filter duplicate data, but also can ensure the correctness of the data reception.

Precise-Optimal Frame Length Based Collision Reduction Schemes for Frame Slotted Aloha RFID Systems

An RFID systems employ efficient Anti-Collision Algorithms (ACAs) to enhance the performance in various applications. The EPC-Global G2 RFID system utilizes Frame Slotted Aloha (FSA) as its ACA. One of the common approaches used to maximize the system performance (tag identification efficiency) of FSA-based RFID systems involves finding the optimal value of the frame length relative to the contending population size of the RFID tags. Several analytical models for finding the optimal frame length have been developed; however, they are not perfectly optimized because they lack precise characterization for the timing details of the underlying ACA. In this paper, we investigate this promising direction by precisely characterizing the timing details of the EPC-Global G2 protocol and use it to derive a precise-optimal frame length model. The main objective of the model is to determine the optimal frame length value for the estimated number of tags that maximizes the performance of an RFID system. However, because precise estimation of the contending tags is difficult, we utilize a parametric-heuristic approach to maximize the system performance and propose two simple schemes based on the obtained optimal frame length.namely, Improved Dynamic-Frame Slotted Aloha (ID-FSA) and Exponential Random Partitioning-Frame Slotted Aloha (ERP-FSA). The ID-FSA scheme is based on the tag set estimation and frame size update mechanisms, whereas the ERP-FSA scheme adjusts the contending tag population in such a way that the applied frame size becomes optimal. The results of simulations conducted indicate that the ID-FSA scheme performs better than several well-known schemes in various conditions, while the ERP-FSA scheme performs well when the frame size is small.

Communication Performance of RFID System and Anti-Interference in the Multipath Rayleigh Fading Channel

With the communication environment of RFID system developing from near field communication to long distance communication, Rayleigh fading with Doppler frequency shift emerges from multipath effect between the readers and electronic tags. A systemic study was focused on modeling and analysis of channel transmission for Type A tag signals in the multipath Rayleigh fading channel. Furthermore, the OFDM system was added to the RFID tag signals to improve the sensitivity of SNR in the Rayleigh fading channel. The SNR of tag signal is not sensitive in the multipath Rayleigh fading channel. However, the sensitivity increases after OFDM is added to the RFID system and the anti-interference ability is highly improved.

A space-time coding approach for RFID MIMO systems

This paper discusses the space-time coding (STC) problem for RFID MIMO systems. First, a mathematical model for this kind of system is developed from the viewpoint of signal processing, which makes it easy to design the STC schemes. Then two STC schemes, namely Scheme I and Scheme II, are proposed. Simulation results illustrate that the proposed approaches can greatly improve the symbol-error rate (SER) or bit-error rate (BER) performance of RFID systems, compared to the non space-time encoded RFID system. The SER/BER performance for Scheme I and Scheme II is thoroughly compared. It is found that Scheme II with the innate real-symbol constellation yields better SER/BER performance than Scheme I. Some design guidelines for RFID-MIMO systems are pointed out.

Effects of a Metal Plane on a Meandered Slot Antenna for UHF RFID Applications

In this paper, the effects of a metal plane on the performance of a meandered slot RFID antenna are evaluated in a real environment, and 3 metal plane cases are considered (the most likely scenarios in which metal conductive materials are placed near the tag antenna). The metal plane effects can be categorized as matching degradation and antenna gain variation. First, matching degradation due to the antenna's induced mutual impedance is experimentally investigated. In addition, the gain variation is investigated to figure out the change in the radiation characteristics. With the derived antenna parameters, the read range is calculated with the Friis transmission equation and measured to analyze the effects of a metal plane on RFID system performance. The calculated and measured read range varies from 9.3 m to 19.1 m as the distance between the RFID antenna and the metal plane changes.

Indirect Coupling Method of Chip Impedance Matched Dipole Antenna for UHF RFID Tag

Radio Frequency Identification is the wireless technology that uses radio waves to automatically identify items within certain proximity. This process involves tagging items with a transmitter which will send bursts of information. Passive RFID tag consists of a microchip connected with an antenna. The passive tag uses the electromagnetic pulse from readers as a power source to transmit its identifier. So proper impedance matching between the antenna and the chip is very important in passive RFID tag design. The RFID system performance characteristics and the range of a tag depend on the impedance matching. A load impedance of RFID microchip is a nonlinear whose complex part varies with the frequency and the input power [2]. This paper presents simulated results of a UHF RFID dipole antenna and inductively coupled with a small rectangular loop. Such a design provides controlled values of inductive reactance that is required for obtaining good impedance match of the antenna to microchip. The proposed dipole antenna is simple and robust in design, which enables low-cost while realization. General Terms Return-loss, 3D Radiation Pattern, 2D Azimuth and Elevation Radiation Pattern, S-Parameters.

Room-Coverage Improvements in UHF RFID with Commodity Hardware [Wireless Corner

This work studies the three-dimensional (3D) identification performance of UHF RFID systems with commodity hardware. Detailed three-dimensional propagation modeling is developed, with ray-tracing that allows examination of tag- as well as reader-antenna diversity. It is shown that multipath can enhance identification performance compared to free-space conditions. Furthermore, it is found that tag diversity can enhance identification performance on the order of 10%. Reader-antenna diversity becomes beneficial only when special attention is given to controlling the destructive summation of the transmitted fields and simple, general antenna-installation rules are provided. Performance can be further enhanced with the introduction of a phase shifter or appropriate transmission scheduling, and various examples are discussed. Measurements inside a room with a dense three-dimensional grid of passive RFID tags confirmed the results. Finally, a method to perform power-measurements with commodity RFID hardware that exploits the sensitivity-during-read threshold of each tag is put forth.