A Study on Multi-carrier Passive RFID System

• Main Authors: Yi-Fan Chen, 陳奕帆
• Other Authors: Hsin-Chin Liu
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/pn6qh7

碩士 === 國立臺灣科技大學 === 電機工程系 === 95 === The present passive Radio frequency identification (RFID) systems use a variety of time division multiple access (TDMA) techniques in individual tag identification. Because only single tag can be identified in the same time, the system performance is inferior to other modern communication systems that incorporating diverse multiple access technologies. In order to improve the tag read rate of the passive RFID system, a novel passive RFID system jointly using frequency division multiple access (FDMA) and TDMA technologies is proposed in this work. In the proposed system, we use the multi-carrier backscattering technology proposed in [4] to receive multiple tag backscatter signals in various frequency bands simultaneously. In order to minimize the co-channel interference (CCI) in each frequency band, a cellular-based deployment is proposed. In order to seamlessly combining the FDMA and TDMA technologies, a modified slotted Aloha algorithm based on the Gen2 standard is also proposed. In addition, a guideline of system power allocation is derived to achieve better overall power consumption. Assuming tags in the interrogator access range are uniformly distributed, a multi-stage interrogation scheme is utilized to further avoid tag collisions and minimize the system power consumption. Simulation results demonstrate distinct performance improvements of the proposed system in terms of the tag identification rate and the overall power consumption.