Spectrum sensing for cognitive radio requires a high linearity to handle strong signals, and at the same time a low noise figure (NF) to enable detection of much weaker signals. Often there is a trade-off between line...
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ISBN:
(纸本)9781424451883
Spectrum sensing for cognitive radio requires a high linearity to handle strong signals, and at the same time a low noise figure (NF) to enable detection of much weaker signals. Often there is a trade-off between linearity and noise: improving one of them degrades the other. Cross-correlation can break this trade-off by reducing noise at the cost of measurement time. An existing RF front-end in CMOS-technology with IIP3=+11dBm and NF
Due to the continuous shrinking of the transistor sizes which is strongly driven by Moore's law, reliability becomes a dominant design challenge for embeddedsystems. Reliability problems arise from permanent erro...
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Due to the continuous shrinking of the transistor sizes which is strongly driven by Moore's law, reliability becomes a dominant design challenge for embeddedsystems. Reliability problems arise from permanent errors due to manufacturing, process variations, aging as well as soft errors. As a result, the hardware will consist of unreliable components and hence, the development of embeddedsystems has to change fundamentally. Therefore, we propose a dependability-aware design approach for hardware systems through integrating dependability into a state-of-the-art system-level design language. Our approach is based on SystemC and extends the Program State Machine model to explicitly observe, diagnose, and compensate faulty behavior. Different compensation mechanisms like run-time reconfiguration or mechanisms for error propagation can be used by the designer during refinement. They are controlled by a new exception-like mechanism. Furthermore, our approach aims to integrate functional verification as well as dependability verification with respect to given fault models.
Spectrum sensing for cognitive radio requires a high linearity to handle strong signals, and at the same time a low noise figure (NF) to enable detection of much weaker signals. Often there is a trade-off between line...
详细信息
Spectrum sensing for cognitive radio requires a high linearity to handle strong signals, and at the same time a low noise figure (NF) to enable detection of much weaker signals. Often there is a trade-off between linearity and noise: improving one of them degrades the other. Cross-correlation can break this trade-off by reducing noise at the cost of measurement time. An existing RF front-end in CMOS-technology with IIP3=+11dBm and NF<6.5dB is duplicated and attenuators are put in front to increase linearity (IIP3=+24dBm). The attenuation degrades NF, but by using cross-correlation of the outputs of the two frontends, the NF is reduced to below 4dB. In total this results in a spurious-free dynamic range (SFDR) of 89dB in 1MHz resolution bandwidth (RBW).
In the last few years, WLAN has seen immense growth and it will continue this trend due to the fact that it provides convenient connectivity as well as high speed links. Furthermore, the infrastructure already exists ...
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In the last few years, WLAN has seen immense growth and it will continue this trend due to the fact that it provides convenient connectivity as well as high speed links. Furthermore, the infrastructure already exists in most public places and is cheap to extend. These advantages, together with the fact that WLAN covers a large area and is not restricted to line of sight, have led to developing many WLAN localization techniques and applications based on them. In this paper we present a novel calibration-free localization technique using the existing WLAN infrastructure that enables conference participants to determine their location without the need of a centralized system. The evaluation results illustrate the superiority of our technique compared to existing methods. In addition, we present a privacy observant architecture to share location information. We handle both the location of people and the resources in the infrastructure as services, which can be easily discovered and used. An important design issue for us was to avoid tracking people and giving the users control over who they share their location information with and under which conditions
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