RF-based Monitoring, Sensing and Localization of Mobile Wireless Nodes

Spectrum sensing and characterization play a very important role in the implementation of cognitive radios and adaptive mobile wireless networks. Most practical mobile network deployments require some level of sensing and adaptation to allow individual nodes to learn and reconfigure based on observations from their own environment. Spectrum sensing can be used for detection of a transmitter in a specific band, which can help cognitive radios to detect spectrum holes for secondary users and to determine the presence of a transmitter in a given area. In addition to determining the existence of a transmitter, information obtained from spectrum sensing can be used to localize a transmitter. In this paper, we focus in oner particular aspect o that problem: the distributed and collaborative sensing, characterization and location of emitters in an open environment. Thus, we propose a software defined radio (SDR)-based spectrum sensing and localization method. The proposed approach uses energy detection for spectrum sensing and fingerprinting techniques for estimating the location of the transmitter. A Universal Software Radio Peripheral (USRP) managed via a small, low-cost computer is used for spectrum sensing. Results obtained from an indoor experimental setup and the K-nearest neighbor algorithm for the fingerprinting based localization are presented in this paper.