A software radio design for communications in uncoordinated networks

This paper describes a simple software radio design approach to communication and spectrum access in a system without user coordination. The work is a result of our recent participation in the DARPA Spectrum Challenge that provides a venue for head-to-head competitions of software radio designs from teams around the country. Two modes of operations are involved, one is competitive and the other cooperative; each mode calls for completely different way of dealing with interference incurred amongst transceiver pairs. Several signal processing issues encountered in the software radio design are described along with their solutions. In addition, we provide our own observations on potential research issues for communication and spectrum access in a congested and uncoordinated environment.