4 research outputs found
Primary exclusive region and optimality of the link-level throughput of cognitive terminals
No full textA cognitive network consists of primary nodes, which have priority access to the spectrum, and cognitive (also referred to as secondary) nodes, which access the spectrum provided that the interference they generate in the primary system remains limited. In practice, it means that the cognitive terminals must remain outside of a region surrounding the primary receiver: the primary exclusive region. The focus of this paper is on the definition of this region and the analysis of the achievable throughput of cognitive terminals under the constraints imposed by the primary network. More precisely, we establish the fundamental limits of the terminal probability of transmission and under what conditions this throughput can still be optimal (in a network throughput sense) for the secondary network.info:eu-repo/semantics/publishe
Primary exclusive region and throughput of cognitive dual-polarized networks
No full textDiversity techniques are of importance in the context of cognitive radio networks since they enable the primary and secondary terminals to simultaneously and efficiently share the spectral resources in the same location. In this paper, we investigate a simple, yet powerful, diversity scheme based on the exploitation of the polarimetric dimension. More precisely, we consider a scenario where the cognitive terminals use cross- polarized communications with respect to the primary users. Our approach is network-centric, i.e. the performance of the proposed dual- polarized system is investigated in terms of link throughput in the primary and the secondary networks. Our results suggest that the polarimetric dimension represents a remarkable (and simple to implement) opportunity in the context of cognitive radio networks.info:eu-repo/semantics/publishe
Polarization orthogonality for the co-existence of wideband fading cognitive networks
No full textOrthogonality techniques for cognitive radio networks are important since they enable the primary and secondary terminals to efficiently share the spectral resources in the same location simultaneously. In this paper, we investigate a simple, yet powerful, orthogonality scheme by exploiting the polarimetric dimension. More precisely, we evaluate a scenario where the cognitive terminals use cross-polarized communications in a communication channel subject to wideband (or narrowband) Rayleigh fading. A primary exclusive region in which cognitive terminals are not allowed to transmit is defined and its radius is computed. Finally, the overall performance of the proposed solution is evaluated in terms of network throughput.info:eu-repo/semantics/publishe
Probabilistic co-existence and throughput of cognitive dual-polarized networks
No full textDiversity techniques for cognitive radio networks are important since they enable the primary and secondary terminals to efficiently share the spectral resources in the same location simultaneously. In this paper, we investigate a simple, yet powerful, diversity scheme by exploiting the polarimetric dimension. More precisely, we evaluate a scenario where the cognitive terminals use cross-polarized communications with respect to the primary users. Our approach is network-centric, i.e. performance of the proposed dual-polarized system is investigated in terms of link throughput in the primary and the secondary networks. In order to carry out this analysis, we impose a probabilistic co-existence constraint derived from an information-theoretic approach, i.e. we enforce a guaranteed capacity for a primary terminal for a high fraction of time. Improvements brought about by the use of our scheme are demonstrated analytically and through simulations. In particular, the main simulation parameters are extracted from a measurement campaign dedicated to characterization of indoor-to-indoor and outdoor-to-indoor polarization behaviors. Our results suggest that the polarimetric dimension represents a remarkable opportunity, yet easily implementable, in the context of cognitive radio networks.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
