Miguel López-Benítez

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Energy detection constitutes a preferred approach for spectrum sensing in cognitive radio due to its simplicity and applicability (it works irrespective of the signal format to be detected) as well as its low computational and implementation costs. The main drawback, however, is its well-known detection performance limitations. Various alternative detection(More)
Several spectrum measurement campaigns have been performed in diverse locations and scenarios in order to assess the degree to which spectrum is currently used in real wireless communication systems. Although such measurement campaigns follow similar approaches, there is a lack of common and appropriate evaluation methodology, which would be desirable not(More)
Cognitive Radio (CR) has been identified as a promising solution to the so-called spectrum scarcity problem. The basic idea of this paradigm is to allow unlicensed users to access in an opportunistic and non-interfering manner some licensed bands that are temporarily unoccupied by licensed users. CR is expected to significantly increase current spectrum(More)
The existing approximations for the GaussianQ-function have been developed bearing in mind applications that require high estimation accuracies (e.g., derivation of the error probability for digital modulation schemes). Unfortunately, the associated mathematical expressions are too complex to be easily employed in many other analytical studies, even if they(More)
This paper presents an empirical time-dimension model of spectrum use in the context of dynamic spectrum access. Concretely, a discrete-time two-state Markov chain with novel duty cycle models is proposed as an adequate mean to accurately describe spectrum occupancy in the time domain. The validity and accuracy of the proposed model is assessed and(More)
The spectrum occupancy models widely used to the date in Dynamic Spectrum Access/Cognitive Radio (DSA/CR) research frequently rely on assumptions and oversimplifications that have not been validated with empirical measurement data. In this context, this work presents an empirical time-dimension model of spectrum use appropriate for DSA/CR studies.(More)
Cognitive radio terminals sense the spectrum to detect temporarily unoccupied spectrum gaps and transmit. The behavior of a network of cognitive radio terminals therefore depends on the spectrum occupancy perceived by each terminal at its local environment. In this context, this work explores (via empirical measurements) the spectrum occupancy that would be(More)
Cognitive radio nodes of a dynamic spectrum access network monitor the spectrum around them in order to detect and opportunistically exploit temporarily unoccupied spectrum gaps. The overall behavior of the whole network depends on the spectrum occupancy perceived by each node at its local environment. An appropriate understanding of the local perception of(More)
Heterogeneous wireless systems are envisaged as the integration and joint cooperative management of diverse radio access networks and technologies through which network providers can satisfy the wide variety of user/service demands in a more efficient manner by exploiting their varying characteristics and properties. To achieve this objective, a key tool is(More)