Tratamento de colisões na leitura de etiquetas RFID sem chip.

Abstract

The constant technological advancement in areas such as identification, tracking and sensing of processes and elements always looks for alternatives to increase speed and facilitate the exchange of information. The radio frequency identification, known by its acronym in English – RFID, although it’s not a new technology, has been pointed as a important alternative in these areas, because of some attractive characteristics that other systems on the market do not have. In this regard, efforts have been made in order to reduce production costs of the RFID elements. As a result, a new strand of research related to RFID has emerged in recent years, the use of tags that do not have integrated circuit. As these elements are the most numerous of the system, this change would help to reduce the production costs substantially. However, changing the tag’s architecture in this way, brings other issues to discussion, with the main one relating to the communication signals between the elements and their problems, such as the reading collisions in environments with more than one tag. From these issues, the main objective of this work is to focus on the treatment of reading collisions for RFID systems with tags which do not have chip and uses the spectral signature as a mean of encoding binary information. As a tool for processing the signals involved in the communication system, its used the Fractional Fourier Transform and its mathematical properties on the separation of colliding signals and the concepts of minimum distance detection for recovery the binary information from the previously separated signals. The method was simulated and produced the expected results, with the effective separation of signals and satisfactory performance identifying tag’s binary information.