Abolfazl Razi
Northern Arizona University, USA
Title: A Two-step Algorithm for Interference Reduction in Wireless Passive Sensor Networks Using Directional Antennas
Biography
Biography: Abolfazl Razi
Abstract
With the recent advances in microelectronics fabrication, low-power communications, information processing and networking protocols, wireless sensing technology has experienced a revolutionary progress in the past decade. It has shifted from a pure lab-based technology to a real-world industry with a wide range of applications in habitat monitoring, agriculture, surveillance and security systems, smart health, transportation, aviation, and smart grid. However, there are a category of applications, where the conventional sensors fail to operate due to extremely harsh environmental conditions. For instance, no active battery-operated active sensor can be deployed to monitor a jet engine temperature. Passive sensor technology is the only solution for these scenarios. In this research, we focus on a special variant of passive sensors developed based on Surface Acoustic Wave (SAW) technology. In this solution, an electromagnetic wave is radiated by an interrogator system and the passive sensors receive the signal, manipulate it and radiate back a copy of the received signal. An advanced signal processing of the backscattering signal reveals an Important set of information about the environmental conditions (such as temperature and stress), and hence these devices can be used for remote sensing. However, an important challenge in using these devices is the interference problem, since the classical TDMA, FDMA and CDMA techniques can not be used for multiple access. The second challenge is the short range of communication links. In this research, we first quantify these challenges and explore the state of the art solutions to solve these problems. Further, we propose an advanced signal processing method for interference reduction dilemma. The proposed algorithm includes two sequential phases: i) configuration detection and ii) interrogation. This algorithm enables multiple passive sensor interrogation using a central interrogator system equipped with a circular antenna array. This technology can solve several unsolved sensing problems in aviation, space exploration, under-ground and underwater sensing applications