International Journal of RF Technologies - Volume 7, issue 2-3

Authors: Salah, Hamed | Ahmed, Hazem A. | Robert, Joerg | Heuberger, Albert

Article Type: Research Article

Abstract: This paper focuses on the rate estimation in radio frequency identification (RFID) reader receivers, which plays a significant role for the stability and the efficiency of RFID systems. RFID readers have to estimate the rate of the tag reply, i.e. the so-called backscatter link frequency (BLF). According to the focused EPCglobal Class-1 Gen-2 standard, the BLF can have a variation of up to +/-22%. Most literature uses time domain algorithms to estimate this BLF. However, the proposed techniques are not suitable to estimate the rate when multiple tags reply simultaneously to the reader. In case of such tag collision we …utilized the frequency domain representation of the replies to estimate the BLF. The performance is tested with different rates and the both supported modulation techniques, i.e. FM0 and Miller. Simulation results show the high performance of utilizing the Fast Fourier Transform (FFT) and Multiple SIgnal Classification (MUSIC) algorithm for estimating the BLF. This especially holds in case of collisions that cannot be easily estimated by means of time domain algorithms. Show more

Keywords: RFID, Rate estimation, FFT, MUSIC, Eigendecomposition

DOI: 10.3233/RFT-150074

Citation: International Journal of RF Technologies, vol. 7, no. 2-3, pp. 87-104, 2016

Authors: Rizzi, A. | Romagnoli, G. | Thiesse, F.

Article Type: Research Article

Abstract: OBJECTIVE: This paper aims at proposing a new framework for the classification of RFID deployments in fashion and apparel retailing. The framework encompasses several different use cases (UCs) pursued by fashion and apparel retailers in the last decade, and updates, expands and goes beyond what has already been presented in the related literature. DESIGN, METHODOLOGY, APPROACH: We carried out a comprehensive literature review on RFID deployments in fashion and apparel retail. We searched different sources of information, that is, scientific papers, conferences and seminars proceedings, websites, magazines, newspapers etc., up to 160 papers that were carefully analysed …and organised in a structured database. This data set also comprehends information from confidential projects. We analyse contents on the level of single RFID projects, that is, feasibility studies, proofs of concept, pilots or deployments. For each project, we determine what specific UCs were at stake. Eventually, the framework of all possible RFID UCs emerged from the analysis, and we set up a panel of industry partners to validate the framework using the Delphi method. FINDINGS: We structured the new framework along two levels: first, 6 categories were identified (i.e., level 1 use cases). Each category was then detailed, resulting in a total of 18 specific UCs (i.e., level 2 use cases). Each level 2 UC corresponds to a very specific objective pursued by an RFID implementation. For each UC, we propose a set of business metrics to evaluate deployment success as well as benefits achieved. PRACTICAL IMPLICATIONS: From a practitioner’s perspective, the framework offers a comprehensive and well-structured overview of the cost- and the revenue-related potentials of RFID implementations in the industry. Researchers, on the other hand, may use the framework to identify opportunities for further research regarding RFID deployments in retailing. ORIGINALITY/VALUE: Our framework is based on the current body of literature, and complements prior studies, which served as the starting point for our research. Show more

Keywords: Fashion and apparel, retailing, RFID deployment, use cases, RFID technology

DOI: 10.3233/RFT-150075

Citation: International Journal of RF Technologies, vol. 7, no. 2-3, pp. 105-129, 2016

Authors: Zhou, Shijie | Liu, Yun | Xu, Jin

Article Type: Research Article

Abstract: This paper presents a new algorithm for RFID deployment in 3D space. We first introduce a cube-based model to describe both the reading space and the coverage space, which can be represented by a 3D matrix. Then, an improved particle swarm optimization algorithm is proposed to implement our cube-based model in the intensive RFID reader deployment. The proposed deployment algorithm is simple and neat, by addition of two matrices. Our solid simulation results show that our cube-based model with improved particle swarm optimization algorithm is a practical scheme for the RFID coverage problem in 3D space.

Keywords: RFID reader, 3D space, deployment, coverage and overlap, RFID network planning

DOI: 10.3233/RFT-150076

Citation: International Journal of RF Technologies, vol. 7, no. 2-3, pp. 131-152, 2016

Authors: Jacobi, Rebekka Carmen | vom Bögel, Gerd | Grabmaier, Anton | Kolossa, Dorothea

Article Type: Research Article

Abstract: In medicine and other high-tech sectors, mobile RFID or sensor transponder systems are designed with high-Q antenna coils to increase the energy efficiency. Hence, the range of inductively coupled systems is improved; however, the bandwidth is decreased by 1 over Q . As a result, the reading performance is not limited by the energy supply, but instead by a high bit error rate. In this paper, we describe how the data detection in such narrow-band systems can be improved by a multilevel decoding scheme composed of an advanced maximum-likelihood receiver in the ?rst stage and a soft Viterbi decoding …scheme utilizing time variant reliability information in the second stage. An analysis of potential time-variant reliability information is given. The analysis relies on an underlying Bayesian model, which provides an a-posteriori probability indicating the reliability of the received input. As the final building block, a last decoding stage is discussed, which can be composed of a forward error correction that further exploits the reliability information at the second decoder output. Overall, the suggested system architecture results in a notable improvement of both bit and packet error rate, thus allowing the use of high-quality-factor antennas for efficient and reliable mobile RFID systems. Show more

Keywords: Radio frequency identification, sensors, maximum-likelihood decoding, matched filters, viterbi algorithm, bayes methods

DOI: 10.3233/RFT-150077

Citation: International Journal of RF Technologies, vol. 7, no. 2-3, pp. 153-173, 2016