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This paper describes a novel autonomously adaptive networked radio system that provides a broadband tactical mobile backbone to enable netcentric warfare. The system was successfully demonstrated to seamlessly interconnect multiple heterogeneous networked radio systems during the DARPA NetCentric (NC) demonstration at Ft. Benning, GA in January 2006, serving as the high availability terrestrial backbone...
The ADROIT project is building an open-source software-defined data radio, intended to be controlled by cognitive applications. The goal is to create a system that enables teams of radios, where each radio both has its own cognitive controls and the ability to collaborate with other radios, to create cognitive radio teams. The desire to create cognitive radio teams, and the goal of having an open-source...
This paper presents a novel and general approach to cognitive radio (CR) networking based on the Radio Environment Map (REM). REM is envisioned to be an integrated database that consists of comprehensive multi-domain information for CR, such as geographical features, available services, spectral regulations, locations and activities of radio devices, policies, and past experiences. Disseminating and...
This paper describes the high value of cognitive radio technology and characterizes the opportunity space in four distinct classes. A Chicago-based spectrum occupancy study illustrates the opportunity showing that 82.6% of the spectral capacity is unused. A set of spectral signatures is presented for common devices in the unlicensed frequency band with the view that this technique can be widely deployed...
For better spectrum utilization, efficient channel allocation in multi-radio wireless mesh networks has become an active research area. Our proposed CARD algorithm deals with the application of cognitive mesh routers for fixed channel assignments to mesh clients under each router's domain. The farthest channel assignment by the cognitive radio in mesh routers ensures minimum inter-router and intra-router...
This paper considers the problem of connecting a collection of nodes to a backbone network. Each node may be directly connected to the backbone, at some cost, or it may communicate wirelessly to a directly connected hub and share its connection, at the "cost" of using spectrum for the wireless link. This problem arises in diverse areas such as cellular network backhaul and overlays of ad-hoc...
In this paper, we present a framework for rate and power allocation in MIMO-OFDM systems using the V-BLAST and SVD techniques. The performance of these techniques are compared with one another and with waterfilling using channel measurements on our MIMO-OFDM software defined radio testbed. Specifically, we show with measured data that sub-carrier rate adaptation allows for more efficient spectral...
A new architecture for a signal processing platform suited for flexible software defined radio called RPPP has been proposed by the authors. In this architecture, the platform can change its functionality clock by clock and multiple function radio equipment is realized flexibility. This paper describes two implementations of SDR using RPPP. One is the receiver for DSRC which can handle two different...
Software Defined Radios (SDR) offer great runtime flexibility both at the physical and MAC layer. This makes them an attractive platform for the development of cognitive radios that can adapt to changes in channel conditions, traffic load, and user requirements. However, to realize this goal, we need a software framework that supports both MAC protocol and PHY layer development in an integrated fashion...
Essential to adaptive devices is the ability to reconfigure Medium Access Control (MAC) protocols to environment conditions and application requirements. We propose MadMAC, a platform for building reconfigurable MAC protocols on commodity 802.11x hardware. Programming on top of MadWiFi, MadMAC transmits packets at configurable time and frame format. In this paper, we build a TDMA-based MAC protocol...
The ongoing research in software-defined radios and the policy/regulation reform by the FCC are paving a road for dynamic spectrum access which allows unlicensed users to access spectrum that has been allocated to a primary user in a dynamic and non-interfering manner, and creates a new type of wireless network termed programmable radio wireless network (ProWin). Due to the non-interfering requirement,...
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