Database-assisted end-to-end theoretical and simulation framework for cognitive radio networks

• Online Access: http://hdl.handle.net/2047/d20004948

Cognitive radios are envisaged to address the problem of spectrum scarcity by opportunistically using licensed bands, without interfering with the higher priority transmissions in them. Recent FCC rulings mandate the use of spectrum databases for obtaining the spectrum usage information, and how to integrate the database coordination with the higher layer networking protocol stack remains an open challenge. This thesis addresses this concern through the following contributions: (a) An end-to-end transport layer called TFRC-CR is devised that uses equation based transmission rate control, and relies on database updates rather than intermediate node information. (b) A framework for vehicular cognitive radio is created that uses cross-correlation between 2G signals obtained from an Android device and signals from the TV white space to reduce the number of database queries. Moreover, this framework also involves a practical demonstration of interference alignment to optimally use the channel during the querying process. (c) An extension for the network simulator-3 that provides cognitive abilities, such as spectrum sensing, primary user detection, and spectrum hand-off to the research community which allows them to simulate these complex radios in a virtual environment.