Practical Guidelines for Approaching the Implementation of Neural Networks on FPGA for PAPR Reduction in Vehicular Networks

Nowadays, the sensor community has become wireless, increasing their potential and applications. In particular, these emerging technologies are promising for vehicles' communications (V2V) to dramatically reduce the number of fatal roadway accidents by providing early warnings. The ECMA-368 wireless communication standard has been developed and used in wireless sensor networks and it is also proposed to be used in vehicular networks. It adopts Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) technology to transmit data. However, the large power envelope fluctuation of OFDM signals limits the power efficiency of the High Power Amplifier (HPA) due to nonlinear distortion. This is especially important for mobile broadband wireless and sensors in vehicular networks. Many algorithms have been proposed for solving this drawback. However, complexity and implementations are usually an issue in real developments. In this paper, the implementation of a novel architecture based on multilayer perceptron artificial neural networks on a Field Programmable Gate Array (FPGA) chip is evaluated and some guidelines are drawn suitable for vehicular communications. The proposed implementation improves performance in terms of Peak to Average Power Ratio (PAPR) reduction, distortion and Bit Error Rate (BER) with much lower complexity. Two different chips have been used, namely, Xilinx and Altera and a comparison is also provided. As a conclusion, the proposed implementation allows a minimal consumption of the resources jointly with a higher maximum frequency, higher performance and lower complexity.This work has been partly funded by projects TERESA-ADA (TEC2017-90093-C3-2-R) (MINECO/AEI/FEDER, UE) and ELISA (TEC2014-59255-C3-3-R)

Etude de performance d’un système de communication ECMA-368 dans un canal réaliste Ultra Large Bande

L’ECMA-368 est une norme récente, qui décrit la couche physique ULB (PHY-UWB) pour un réseau personnel sans fil (WPAN). Dans cet article, nous allons concevoir et évaluer les performances en termes de taux d'erreur binaire (TEB) d’un système de communication qui respecte la norme ECMA-368 en utilisant les différents modèles de canal ULB définis par la norme IEEE802.15.3a et avec l’ensemble des débits binaires

Dimensioning an FPGA for Real-Time Implementation of State of the Art Neural Network-Based HPA Predistorter

International audienceOrthogonal Frequency Division Multiplexing (OFDM) is one of the key modulations for current and novel broadband communications standards. For example, Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM) is an excellent choice for the ECMA-368 Ultra Wide- band (UWB) wireless communication standard. Nevertheless, the high Peak to Average Power Ratio (PAPR) of MB-OFDM UWB signals reduces the power efficiency of the key element in mobile devices, the High Power Amplifier (HPA), due to non-linear distortion, known as the non-linear saturation of the HPA. In order to deal with this limiting problem, a new and efficient pre-distorter scheme using a Neural Networks (NN) is proposed and also implemented on Field Programmable Gate Array (FPGA). This solution based on the pre-distortion concept of HPA non-linearities offers a good trade-off between complexity and performance. Some tests and validation have been conducted on the two types of HPA: Travelling Wave Tube Amplifiers (TWTA) and Solid State Power Amplifiers (SSPA). The results show that the proposed pre-distorter design presents low complexity and low error rate. Indeed, the implemented architecture uses 10% of DSP (Digital Signal Processing) blocks and 1% of LUTs (Look up Table) in case of SSPA, whereas it only uses 1% of LUTs in case of TWTA. In addition, it allows us to conclude that advanced machine learning techniques can be efficiently implemented in hardware with the adequate design

Manufacture of Clay Aggregate Doped with Pozzolan Destined for Lightweight Concrete

In this work, marl clay was used because these materials have a very important industrial potentiality in several fields, namely ceramics. The objective was manufacturing expanded clay aggregate (ECA), with two main ingredients of marl and pozzolan at different percentages in order to integrate them into the concrete as aggregate. The physicochemical parameters of the mixture marl / Pozzolan was discussed and the results of the analyses, allowed deducing that the sample with 15% pozzolan has the most expansion rate of 16.8%, and its density of 1232 kg/m3 is in accordance with the international standard of expanded aggregates. The density of the concrete decreases with the quantity of ECA added and reaches its minimum with 1671 kg/m3 according to concrete with 50% of the expanded aggregate. The bending tests show the increase of the mechanical strength as a function of the quantities of aggregate added. The results show a very important potential with the addition of clay aggregates, density and water absorption decrease with the increase of the mechanical resistance

PERFORMANCE EVALUATION OF CEMENT MORTAR CONTAINING CONSTRUCTION AND DEMOLITION WASTE AS SUPPLEMENTARY CEMENT MATERIALS

The purpose of this study is to investigate the effect of fine powders from construction and demolition waste (CDW) as a replacement for cement on the properties of fresh and hardened cement paste and mortar. Specifically, the study focuses on three types of waste powders (WPs) which are: waste brick powder (WBP), waste concrete powder (WCP) and mixed waste powder (MWP). Each type of WP is used to replace 0% to 15% of cement. First, the milled powders are assessed in terms of their morphology (SEM) and composition (X-ray diffraction (XRD) and X-ray fluorescence (XRF)). Such an assessment is carried out based on consistency and setting time tests in order to examine the fresh behaviour of the cement pastes. Second, the mechanical properties, mineralogical and microstructural characteristics are evaluated in order to elucidate the effect of various WPs on the mortar samples. The results demonstrate that, according to the required standards, the use of each WP up to 15% does not alter the mechanical properties of the cement mortar. However, the use of 5% and 10% WBP replacement levels was adequate for improving the strength. Thus, a 52.9 MPa maximum strength was achieved with this mix. Furthermore, the microstructure analyses indicate that the WBP and WMP show a denser mortar structure compared to the reference one. Consistent with the microstructural analyses, the mineralogy analysis reveals that the WBP and MWP have a significant impact on the hydration products of the elaborated mortars

The kinetics of IgG Antibodies in Critically Ill Patients

the kinetics of SARS-CoV-2 antibodies response and factors predicting igG levels are still limited. We report a prospective analytical study of patients admitted for SARS-cov-2 in the medical intensive care unit of the Mohammed VIth University Hospital of Marrakech for three months.We measured the level of igG antibodies to SARS-Cov-2 on plasma blood samples from all patients collected on admission  and then every seven days respectively until discharge or death. The kinetics of antibodies with disease progress were analyzed. The mean igG levels increased between ICU admission till day 21, then they dropped on day 28. Critical patients had higher igG levels than severe ones with no statistically significant difference. Between day one and day 14, males had higher igG levels than females; however, females had higher levels on days 21 and 28 with a statistically significant difference on day 28. On the chest CT scan, patients with ground-glass opacities and/or crazy paving distribution of 75% or more had higher igg levels with a statistically significant difference on day 7. In terms of mortality, deceased patients had higher igG levels with no statistically significant difference than survivors. Our results may suggest the incrimination of SARS-cov-2 igg antibody high level as a prognostic factor for disease severity

Characterization of Serracin P, a Phage-Tail-Like Bacteriocin, and Its Activity against Erwinia amylovora, the Fire Blight Pathogen

Serratia plymithicum J7 culture supernatant displayed activity against many pathogenic strains of Erwinia amylovora, the causal agent of the most serious bacterial disease of apple and pear trees, fire blight, and against Klebsiella pneumoniae, Serratia liquefaciens, Serratia marcescens, and Pseudomonas fluorescens. This activity increased significantly upon induction with mitomycin C. A phage-tail-like bacteriocin, named serracin P, was purified from an induced culture supernatant of S. plymithicum J7. It was found to be the only compound involved in the antibacterial activity against sensitive strains. The N-terminal amino acid sequence analysis of the two major subunits (23 and 43 kDa) of serracin P revealed high homology with the Fels-2 prophage of Salmonella enterica, the coliphages P2 and 168, the φCTX prophage of Pseudomonas aeruginosa, and a prophage of Yersinia pestis. This strongly suggests a common ancestry for serracin P and these bacteriophages

Bacteriocine, sa préparation et son utilisation

publication date: 2000-12-21; filing date: 2000-06-0