Cognitive Radio Technology

The Phase I objective is to research and develop enabling technologies to build a multi-functional Software Defined Radio based Cognitive Radio Network (SDR based CRN) capability, which will maximize the spectrum efficiency by utilizing both unused and underused spectrum of opportunity. We develop a non-contiguous waveform algorithm that determines the sub-band frequency limits and sub-band maximum transmit power levels considering: (1) Non-ideal transmitter power amplifiers (with inter-modulation distortion that fills in the transmitted spectrum between sub-bands), and (2) Non-uniform legacy radio channel usage (each legacy channel has different temporal occupancy statistics). We develop a distributed, geographic and frequency based, distributed sensing and transmission algorithm to enable heterogeneous systems (communications, SIGINT, Jamming, and radar) to share each other’s sensing and transmissions to satisfy joint goals. We develop a method to efficiently exchange spectrum measurements between heterogeneous nodes and to determine each node’s sensing and transmission tasks. We determine the design metrics necessary to implement these techniques on commercially available SDRs for Phase II development and for near-term DoD deployment. BENEFIT: Military application: This system could be used in a very broad range of civilian and military applications. Communication systems and networks exist in numerous forms (cell phones, radio comms, wireless data networks, etc.) and this technology could be applied to all aspects of them. Spectrum efficiency is of utmost importance to commercial communications companies looking to improve quality of service (QoS) for their users. Military radar technology could be enhanced by the CRN technology as well.