Cognitive Radio Platform Development for Interoperability
Scaperoth,David
Center for Wireless Telecommunications, Virginia Tech
Rondeau,Tom
Center for Wireless Telecommunications, Virginia Tech
Maldonado,David
Center for Wireless Telecommunications, Virginia Tech
Le,Bin
Center for Wireless Telecommunications, Virginia Tech
Harrison,Steve
Innovative Wireless Technologies
Bostian,Charles
Center for Wireless Telecommunications, Virginia Tech
Like the military, public safety agencies face problems with current radios: incompatibility between models with different waveforms and frequencies, unreliable quality, and poor or nonexistent network capabilities that rely on simple broadcasting. Cognitive radio (CR) technology is a promising solution for both communities. Being aware of its environment, a CR can recognize the existing communication devices and networks and discover the optimal access opportunity and method in a robust and secured way.
We are developing a generalized CR platform to provide solutions for intelligent wireless communications to enable secure, full-scale connectivity with controllable service quality (voice and data) for public safety. Our platform involves both hardware and software implementatons. The design philosophy uses software-defined radio (SDR) as the hardware platform and smart software algorithms to implement cognitive functionality.
This CR platform is able to reconfigure in real-time a number of key parameters (center frequency, transmit power, modulation type, etc.) that define quality of service. The GNU Radio project provides a good prototype platform for this research. The platform developed at Virginia Tech configures the SDR based on information given by an implementation document written in XML. The XML file allows powerful connections between any number of software applications: an intelligent decision making software program or a user interface operated via the Internet. The XML file is passed to an Application Programming Interface (API) that organizes and initializes the information in order to configure the SDR. The API is the key element for organizing the transmit and receive paths of the radio and the parameters (filter characteristics, muti-rate conversion, etc.) that are described in the XML document. This structure allows easily defined radio implementations. The radio platform used at Virginia Tech will be capable of communicating with both analog and digital waveforms defined in this way.
The API structure developed here will find initial applications in public safety and military communications to provide low-cost, multiband operation from SDR technology for interoperability between frequency bands and waveforms. Current work is already showing the promise of this technology.
David Scaperoth is a Master's student at Virginia Polytechnic and State University specializing in software defined radio and cognitive applications. His undergraduate degree is in Electrical Engineering from the University of Tennessee, Knoxville. David is currently a software engineer at Raytheon Company in their Intelligence and Information Systems Group located in Falls Church, VA.