The communications adaptive design and RFI environment (CADRE) tool for radio system design

The United States (U. S.) government operates several communications systems in the 960-1215 megahertz (MHz) band. There is an increased threat of potential mutual radio frequency interference (RFI) due to government plans to upgrade current systems and/or implement future systems within this band. Furthermore, the 960-1215 MHz band is susceptible to in-band and out-of-band interference caused by future third-generation (3G) commercial systems (e.g. ultra-wideband and Global System for Mobile Telecommunications), which have been proposed to operate in this band or in bands adjacent to it. The complex radio frequency interactions of these systems can be difficult to quantify by using strictly analytical models, especially when trying to accurately determine the degradation in system performance caused by mutual RFI. Recognizing this critical issue, the MITRE Corporation's Center for Advanced Aviation System Development (MITRE/CAASD) began exploring, developing, and assembling separate simulation tools into a tool suite to help users make effective decisions regarding system design and efficient spectrum use. The tool suite is called the Communications Adaptive Design and RFI (Radio Frequency Interference) Environment (CADRE) Tool Suite. This paper describes the modeling effort conducted at MITRE/CAASD and provides simulation results. The Universal Access Transceiver (UAT) was selected for analysis using CADRE and the results obtained from CADRE were validated by comparing them to actual measurement results obtained from laboratory tests conducted at the Joint Spectrum Center (JSC) by members from the FAA, JSC, Johns Hopkins University Applied Physics Laboratory, and MITRE. The two sets of results agreed favorably, thus demonstrating the integrity and accuracy of CADRE for system modeling.