George Sklivanitis

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This article describes the design of a custom software-defined modem with adaptive physical layer for underwater acoustic (UWA) communications. The modem consists of a commercial software-defined radio (SDR) interfaced with a wideband acoustic transducer through amplifying circuitry. With this custom-built platform, we focus on the unique physical layer(More)
—Existing commercial wireless systems are mostly hardware-based, and rely on closed and inflexible designs and architectures. Moreover, despite recent significant algorithmic developments in cross-layer network adaptation and resource allocation , existing network architectures are unable to incorporate most of these advancements. While software-defined(More)
M odern digital communications, informatics, and electronics increasingly blend together in our daily lives. Cell phones, for example, have evolved into powerful, handheld computers with smart human-computer interfaces, broadband wireless connectiv-ity, and a multitude of sensors (cameras, capacitive touch-screens, accelerometers, GPS receivers, and so on).(More)
—We propose a receiver configuration and we develop a software-defined-radio testbed for real-time cognitive underwater multiple-access communications. The proposed receiver is fully reconfigurable and executes (i) all-spectrum cognitive channelization and (ii) combined synchronization, channel estimation , and demodulation. Online (real-time) experimental(More)
We present the setup of a complete software-defined radio (SDR) testbed for non-coherent zero-feedback distributed beamforming. Three custom-built, embedded RF transceivers along with a commodity, low-cost SDR commercial receiver are deployed in an indoors lab environment. In sharp contrast with prior art on collaborative beamforming, the proposed scheme(More)
We present the first complete software-based framework for real-time experimental evaluation of secondary multi-hop cognitive underlay networks with decentralized control. We build a $7$-node software-defined radio testbed and implement a distributed algorithm that maximizes the secondary network throughput, while at the same time avoids interference to(More)
We implement and real-time demonstrate for the first time ROCH; a distributed cognitive algorithm that maximizes secondary network throughput, while at the same time avoids interference to primary users through joint Routing and cOde-waveform CHannelization. ROCH performance is evaluated on a $7$-node software-defined radio testbed using the open-source(More)