RF Monitoring

Chun-Ta Kung, Neeraj Venkatesan            Advisor: Ivan Seskar



The USRP2 is a hardware kit that allows pairing with any RF Daughterboard to make a software radio. The daughterboard we used is the XCVR2450 model. The platform for cooperative spectrum sensing we are working on is built to work on this platform. The USRP2 can sense up to 25MHz of spectrum instantaneously rather than the 8 MHz of its predecessor. This is better suited to our task of RF Monitoring as it enables us to sense more quickly and with fewer passes.                


The Universal Hardware Driver(UHD), as its name suggests, is a driver for controlling the USRP2. The motivation behind using this is the fact that it reads samples from the USRP2 in packets rather than a continuous stream. Furthermore, UHD provides an API, which allows for tagging the data packets with timestamps. This is of great importance in this project because when using multiple USRP2’s, time stamping is required to “stitch” the data together from various sensors to form a coherent spectrum picture.


All experiments and tests of the framework are done
on the Orbit Testbed and its sandboxes. The Orbit lab has 2 USRP2’s in a separate sandbox environment as well as 4 USRP2’s in the main grid for cooperative sensing tests.