Simulation of a radio frequency identification system utilizing direct sequence spread spectrum and additional improvement techniques
Radio Frequency Identification (RFID) is a technology that has been in use since World War II and has evolved from the means by which an army was able to identify approaching aircraft to a versatile data gathering tool which is used in a variety of applications. Paramount concerns to any RFID system include accuracy, data security, system capacity and efficiency as well as system architectures to take into consideration the unique aspects of particular applications. In this work, a generalized RFID system is developed to allow multiple passive RFID tags to simultaneously communicate with a single reader. Applications include inventory, retail checkout, industrial process tracking, and security. The system uses direct sequence spread spectrum (DSSS) as its multiple access technique, and several unique system modifications are proposed to improve the accuracy and capacity of the generalized system. Simulation results show the performance of the generalized system and show that the proposed modifications to the system do in fact improve the system's accuracy and capacity, both in a noiseless environment and in an environment with additive white Gaussian noise. A comparison of the proposed modifications is performed and suggestions for their implementation are discussed.