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On Spectrum Probing In Cognitive Radio Networks: Does Randomization Matter, Chao Chen, Zesheng Chen, Todor Cooklev, Carlos Pomalaza-Ráez
On Spectrum Probing In Cognitive Radio Networks: Does Randomization Matter, Chao Chen, Zesheng Chen, Todor Cooklev, Carlos Pomalaza-Ráez
Todor Cooklev
In cognitive radio networks, dynamic spectrumaccess is achieved by allowing secondary users (SUs) to probethe spectrum and utilize available channels opportunistically.Spectrum probing mechanisms should be efficient and fast toavoid harmful interference with primary users (PUs). Periodicprobing has been commonly adopted as a default spectrumprobing mechanism. In this paper, we attempt to study differentspectrum probing mechanisms and evaluate a performance metriccalled the probing delay, i.e., how quickly a probing mechanismcan detect a channel change. We find that randomization in theprobing strategy does affect the probing delay. Specifically, in theindependent sensing scenario, periodic probing indeed achievesthe smallest probing delay. In the cooperative …
Uwb-Fsk: Performance Tradeoffs For High And Low Complexity Receivers, Todor Cooklev, Fernando Ramirez-Mireles, G. A. Paredes-Orozco
Uwb-Fsk: Performance Tradeoffs For High And Low Complexity Receivers, Todor Cooklev, Fernando Ramirez-Mireles, G. A. Paredes-Orozco
Todor Cooklev
In this work we explore flexible modulations toallow demodulation using receivers with different complexityand cost. More specifically, we study pulse-based ultrawideband (UWB) communications over channels with densemultipath effects using frequency shift keying (FSK) datamodulation. Our aim is to explore the performance tradeoffsbetween high and low complexity receivers. For this purposewe determine the performance of coherent, non-coherent andmismatched (e.g., non-coherent detection using templatesconsisting of a single path) demodulators. We take intoaccount the influence of the frequency response of the antennasystem and the effects of the frequency selectivity of themultipath channel. Given a specific channel condition, wederive expressions for the bit error …
Describing Radio Hardware And Software Using Owl For Over-The-Air Software Download, Todor Cooklev, Stanchev, David Clendenen
Describing Radio Hardware And Software Using Owl For Over-The-Air Software Download, Todor Cooklev, Stanchev, David Clendenen
Todor Cooklev
Recently, several researchers have discovered the need for radios to use description techniques. Previous research describes information such as the current frequency band, waveform, and so on. However, this information is presented at a level that is not sufficient to determine software/hardware compatibility for over-the-air software download. For example, a device should not attempt to download a wideband waveform if its radio front-end is only narrowband, or if its baseband hardware cannot provide the required MIPS for the new waveform. Over-the-air software download is one of the most interesting features of software-defined radios. The compatibility between software and hardware prior …