26 research outputs found
Evolution to 200G Passive Optical Network
New generation passive optical network aims at providing more than 100 Gb/s
capacity. Thanks to recent progress enabling a variety of optical transceivers
up to 40 Gb/s, many evolution possibilities to 200G PONs (passive optical
network) could be investigated. This work proposes two directly deployable
cases of evolution to 200G PON based on the combination of these improved
optical transceivers and WDM (wavelength division multiplexing). The physical
layer of the optical network has been simulated with OptiSystem software to
show the communication links performances behavior when considering key
components parameters in order to achieve good network design for a given area.
The complexity of the proposed architectures and financial cost comparisons are
also discussed.Comment: http://www.davidpublishing.com/davidpublishing/Upfile/2/7/2013/2013020707494407.pd
Plant-Mediated Synthesis of Silver Nanoparticles: Their Characteristic Properties and Therapeutic Applications
Plant-Mediated Synthesis of Silver Nanoparticles and Their Stabilization by Wet Stirred Media Milling
Note Technique: estimation de canal dans un contexte Massive MIMO et contamination des symboles pilotes pour différents types d'architecture de récepteur
In this paper we address the problem of channel state information guessing algorithms in the context of massive MIMO systems. We illustrate the problem of pilot contamination in the case where several cells share the same spectrum bandwidth and we calculate the capacity of the system for different receiver architectures: Maximum Ratio Combining, Zero-Forcing, MMSE. The theoretical expressions we obtained are the most accurate ones in the open literature of the field.dans ce papier nous traitons le problème de l'estimation des canaux dans un contexte massive MIMO. Nous illustrons le problème de la contamination des symboles pilotes dans le cas où plusieurs cellules partagent les mêmes bandes de fréquence et nous calculons la capacité du système pour différents types d'architecture de récepteur: Maximum Ratio Combining, Zero-Forcing, MMSE. Les expressions théoriques obtenues sont les plus précises que l'on puisse trouver dans la littérature scientifique
Note Technique: CSI estimation in massive MIMO systems and pilot contamination for MMSE receiver architecture
In this paper we address the problem of channel state information guessing algorithms in the context of massive MIMO systems. We illustrate the problem of pilot contamination in the case where several cells share the same spectrum bandwidth and we calculate the capacity of the system for MMSE receiver. The theoretical expressions we obtained are the most accurate ones in the open literature of the field
Note Technique: CSI estimation in massive MIMO systems and pilot contamination for Zero Forcing receiver architectures
In this paper we address the problem of channel state information guessing algorithms in the context of massive MIMO systems. We illustrate the problem of pilot contamination in the case where several cells share the same spectrum bandwidth and we calculate the capacity of the system for Zero-Forcing receiver. The theoretical expressions we obtained are the most accurate ones in the open literature of the field
Note Technique: CSI estimation in massive MIMO systems and pilot contamination MRC receiver architecture
In this paper we address the problem of channel state information guessing algorithms in the context of massive MIMO systems. We illustrate the problem of pilot contamination in the case where several cells share the same spectrum bandwidth and we calculate the capacity of the system for Maximum Ratio Combining receiver. The theoretical expressions we obtained are the most accurate ones in the open literature of the field
Universal Access Index assessment and appropriate optimization strategy
International audienceInformation and communications technologies (ICTs) are the basis of globalization evolution. In Africa, particularly, the lightning mobile telephony evolution marked by the implementation of wide-band infrastructures has promoted the evolution of ICT in urban areas. It is important, on the other hand, to underline that this evolution in a country is not observed in a proportional way among the various urban and rural areas. In this context, an overall approach of assessment and optimization of the universal access service index in a country, called Universal Access Index, is proposed in this paper. The optimization approach suggested is based on the implementation of corrective actions related to the Universal Service Access Fund and takes into account the intrinsic technical–economic constraints in every area. To assimilate the updated definition of the International Telecommunications Union on the universal access, two significant indicators representing the voice services and data services were integrated in the modelling approach. This approach is applied to a real case study of the state of Ouaddaï in Chad which makes it possible to highlight its relative simplicity of implementation
Radio access model for universal service
International audienceThis paper proposes a mathematical model as a decision tool for the choice of radio access solutions adapted to a geographical region through universal access. It integrates the formalism related to engineering radio network access in general as well as financial constraints imposed by the access and universal service funds. Services considered are voice and data services. This approach has helped to derive a general expression set for radio technologies. The coverage and capacity deployment strategy has also been combined to clarify the optimal implementation based on financial constraints. A case study on the Ouaddai region in Chad accompanied by simulations curves for wireless technologies as Wi-Fi, WiMAX and CDMA for example has shown the efficiency of such approach