Analysis of bit error rate performance of active and passive RFID communication systems with diversity

Abstract

Radio Frequency Identification (RFID) is a wireless data communication technology, which uses Radio Frequency wave for communicating between the reader and the tag. Over the past few decades this massively expanding technology has drawn considerable attention in the microwave community due to its use in a diversity of application like communication, ticketing, transportation, tracking, inventory management, security, retail stock management, parking access control, toll collection, health-care etc. The technology is proved to be more effective than the usual barcode system due to its superior read range, faster data handling capacity, improved security and rugged features. Although there are numerous researches carried out on RFID communication systems during the last few decades, limitations on achieving considerable read range and better data handling capacity using ultra wide band (UWB) still exists. In this thesis paper, diversity in the tag and the reader receiver is applied for UWB to improve the read range of the RFID communication systems. Analysis is carried out with both fixed and variable transmit power using MPAM, MPSK, BPSK and QPSK modulation technique to find out the signal to noise ratio at the output of the diversity combiner. The analysis that has been evaluated from previous works, has resulted in the development of the expressions of the BER for both the active and the passive RFID communication systems. The performance results are evaluated in terms of BER, received power and read range for different receiver diversity and modulation order. Finally a comparative analysis of all the findings are done and a brief idea regarding possible future scopes for further developments of the system is proposed. The main contribution of this thesis involves finding better system performance of an RFID communication system in terms of read range and received power and evaluate the interrelationship between its different system parameters. The application of different environmental parameters in the average BER expression evaluated from the expression of conditional BER and the probability density function for different modulation technique has given new analytic findings. Besides the interrelationship between the received power, BER, read range, receiving antenna, transmit power, modulation order and spectral efficiency using such approach is new in the science community. The outcome of the thesis is expected to give an improved performance of active and passive RFID communication systems in detecting the tag at a comparatively longer distance and will be useful for the design of RFID communication systems in the near future.