Search results for "Multiplex"
showing 10 items of 337 documents
<title>Evolution of optical links toward full-optical transparency</title>
2003
In this paper we review issues of evolution of optical networks towards their full optical transparency and present sequence of eliminating non-transparent elements out of optical links (networks). Architectures of optical commutators with electrical and optical cores have been presented, as well as a structure of OMO (optical-millimeter wave-optical) switching fabric. An example of pure al-optical switch, made by Luxcore, utilizing dispersion compensating elements, wavelength converters and and variable optical attenuators (VOA) operating entirely in optical domain without optical-electrical-optical (OEO) conversions, was quoted. We brought up an issue of all-optical 3R signal regeneration…
Sparsity-aware narrowband interference mitigation and subcarriers selection in OFDM-based cognitive radio networks
2016
In this paper, the performance of an orthogonal frequency division multiplexing overlay cognitive radio network with subcarrier selection schemes is investigated. We propose three subcarrier selection techniques that reduce the level of interference at the primary base station based on collected channel state information from the different network nodes. Approximated outage probability expressions are also derived and verified by simulations for the different studied techniques. In addition, we propose and investigate a new approach for asynchronous narrowband interference (NBI) estimation and mitigation in cognitive radio networks. The proposed approach does not require prior knowledge of …
A Sparsity-Aware Approach for NBI Estimation and Mitigation in Large Cognitive Radio Networks
2016
Underlay cognitive networks should follow strict interference thresholds to operate in parallel with primary networks. This constraint limits their transmission power and eventually the coverage area. Therefore, in this paper, we first design a new approach for asynchronous narrow-band interference (NBI) estimation and mitigation in orthogonal frequency-division multiplexing cognitive radio networks that does not require prior knowledge of the NBI characteristics. Our proposed approach allows the primary user to exploit the sparsity of the secondary users' interference signal to recover it and cancel it based on sparse signal recovery theory. We also propose two subcarrier selection schemes…
Combined Analysis of OFDM-UWB Transmission in Hybrid Wireless-Optical Access Networks
2009
[EN] The hybrid wireless-optical transmission of ultra-wideband signals employing orthogonal frequency-division multiplexing modulation (OFDM) ultra-wideband (UWB) as defined in the ECMA-368 standard is experimentally analyzed in this letter. The OFDM-UWB signals provide 400 Mb/s per user at optical distances from 5 to 50 km on standard single-mode fiber (SSMF). The analysis includes the wireless radiation from 0 to 3 m after optical transmission. The results indicate a maximum error-vector-magnitude degradation of 2.5 dB measured at 1.5-m radio after 50-km SSMF optical transmission for the first two UWB channels. This degradation translates to 1-m maximum wireless-reach penalty.
New distributed model for synthesis of classical dual mode filters
2010
Up to now, distributed models for classical dual mode filters have not been developed. In this paper, the whole procedure to derive such distributed models is shown step by step. The resulting formulas are very similar to those standard ones used for in-line filters since the 1960s. Model limitations, very similar to those related to classical formulas, in terms of precision and bandwidth, are pointed out. Finally, two practical examples of distributed models of dual mode filters for satellite transponders with different orders have been extracted.
Analyses of Dual Polarization WDM and SCM Radio over Fiber and Radio over FSO for C-RAN Architecture
2016
En este trabajo se simulan y verifican experimentalmente los esquemas de transmisión para una Arquitectura de Red de Acceso Radio Centralizada (C-RAN) basados en la combinación de dos tecnologías: Radio sobre Fibra (RoF) y Radio sobre FSO (RoFSO). Las configuraciones propuestas se optimizan para la evolución a largo plazo (LTE) con un ancho de banda de 20 MHz utilizando una modulación de amplitud en cuadratura de 64-QAM en términos de magnitud de vector de error (EVM). En primer lugar, se comparan las mediciones de la multiplexación por división de polarización mediante la combinación de RoF y RoFSO (PDM-RoF/FSO) con los modelos de simulación. Esto se amplía con la combinación de PDM-Multip…
Development of an optical link card for the upgrade phase II of TileCal experiment
2010
This work presents the design of an optical link card developed in the frame of the R&D activities for the phase 2 upgrade of the TileCal experiment as part of the evaluation of different technologies for the final choice in the next two years. The board is designed as a mezzanine which can work independently or plugged in the Optical Multiplexer Board of the TileCal backend electronics. It includes two SNAP 12 optical connectors able to transmit and receive up to 75 Gbps and one SFP optical connector for lower speeds and compatibility with existing hardware as the Read Out Driver. All processing is done in a Stratix II GX FPGA. Details are given on the hardware design including signal and …
Efficient pipeline FFT processors for WLAN MIMO-OFDM systems
2005
The most area-efficient pipeline FFT processors for WLAN MIMO-OFDM systems are presented. It is shown that although the R2/sup 3/SDF architecture is the most area-efficient approach for implementing pipeline FFT processors, RrMDC architectures are more efficient in MIMO-OFDM systems when more than three channels are used.
Design of a mezzanine card with bandwidth aggregation for HPGe gamma spectroscopy
2016
In experimental nuclear physics, HPGe segmented detectors are used to provide high energy resolution of the gamma rays. Besides, 4pi configuration is common to get a full coverage of the interaction point and detection of all the products of the collisions. In this type of experiments, the number of electronic channels can be high (>100) and also the sampling frequency of the digitizing system (>100 Msps). This results in a high data rate per channel (> 2 Gbps) and thus a high aggregated bandwidth to process. In principle, this problem can be solved using a parallel data acquisition system where the input channels (commonly arriving through optical fibers) are read and processed accordingly…
Evaluation of a multiplex reverse transcriptase PCR ELISA for the detection of nine respiratory tract pathogens.
2003
A multiplex reverse transcription (RT) polymerase chain reaction combined with a microwell hybridization assay (m-RT-PCR-ELISA) was previously developed to detect nine different microorganisms: enterovirus (EV), influenza virus type A (IVA) and type B (IVB), respiratory syncytial virus (RSV), parainfluenzavirus type 1 (PIV1) and type 3 (PIV3), adenovirus (AV), Mycoplasma pneumoniae (Mpn), Chlamydia pneumoniae (Cpn) in a single test. These organisms do not usually colonize the respiratory tract of humans, but, if present, it may be assumed they are involved in respiratory disease.The m-RT-PCR-ELISA was tested on (i) culture supernatants of unknown contents, (ii) by determining the analytical…