Beyond Gbps Turbo Decoder on Multi-Core CPUs

International audienceThis paper presents a high-throughput implementation of a portable software turbo decoder. The code is optimized for traditional multi-core CPUs (like x86) and it is based on the Enhanced max-log-MAP turbo decoding variant. The code follows the LTE-Advanced specification. The key of the high performance comes from an inter-frame SIMD strategy combined with a fixed-point representation. Our results show that proposed multi-core CPU implementation of turbo-decoders is a challenging alternative to GPU implementation in terms of throughput and energy efficiency. On a high-end processor, our software turbo-decoder exceeds 1 Gbps information throughput for all rate-1/3 LTE codes with K < 4096

Energy Consumption Analysis of Software Polar Decoders on Low Power Processors

International audienceThis paper presents a new dynamic and fully generic implementation of a Successive Cancellation (SC) decoder (multi-precision support and intra-/inter-frame strategy support). This fully generic SC decoder is used to perform comparisons of the different configurations in terms of throughput, latency and energy consumption. A special emphasis is given on the energy consumption on low power embedded processors for software defined radio (SDR) systems. A N=4096 code length, rate 1/2 software SC decoder consumes only 14 nJ per bit on an ARM Cortex-A57 core, while achieving 65 Mbps. Some design guidelines are given in order to adapt the configuration to the application context

An Efficient, Portable and Generic Library for Successive Cancellation Decoding of Polar Codes

International audienceError Correction Code decoding algorithms for consumer products such as Internet of Things (IoT) devices are usually implemented as dedicated hardware circuits. As processors are becoming increasingly powerful and energy efficient, there is now a strong desire to perform this processing in software to reduce production costs and time to market. The recently introduced family of Successive Cancellation decoders for Polar codes has been shown in several research works to efficiently leverage the ubiquitous SIMD units in modern CPUs, while offering strong potentials for a wide range of optimizations. The P-EDGE environment introduced in this paper, combines a specialized skeleton generator and a building blocks library routines to provide a generic, extensible Polar code exploration workbench. It enables ECC code designers to easily experiments with combinations of existing and new optimizations , while delivering performance close to state-of-art decoders

Fast Simulation and Prototyping with AFF3CT

International audienceThis demonstration intends to present AFF3CT (A Fast Forward 3rror Correction Tool). The main objective of AFF3CT is to provide a portable, open source, fast and flexible software to the channel coding community in such a way that researchers can spend more time on channel coding / algorithmic problems instead of software development issues. It is also intended to facilitate the process of hardware verification and debug with the objective of fast prototyping. I. SIMULATION OF A DIGITAL COMMUNICATION CHAIN Despite the wide variety of existing communication systems , all of them are based on a common abstract model that was proposed by the genius founder of information theory, Claude Shannon [1]. Figure 1 shows the synoptic of such a communication chain. In this structure, the channel encoder and decoder determine the achievable error rate of the system. Moreover, the channel decoder is a large contributor in the overall computational complexity of the system. On the eve of the 5th generation of mobile communication systems, one of the challenges is to imagine systems able to transmit a huge amount of data in a very short amount of time at a very small energy cost in a wide variety of environments. In such a context, researchers work at refining some existing coding schemes (encoder + decoder) in such a way that the system has a low residual error rate and that the associated decoder is fast, flexible and has a low complexity. The validation of a new coding scheme requires the estimation of the error rate performance. Unfortunately, most of the time, no simple mathematical model exists to predict the performance of a channel encoder/decoder. The only simple solution is to perform a Monte Carlo simulation of the whole communication chain: some data are pseudo-randomly generated, encoded, modulated, noised, decoded and the performance is estimated by measuring the Bit Error Rate (BER) and the Frame Error Rate (FER) at the receiver side. This apparently simple setup leads to three main problems. Reproducibility: It is usually a tedious task to reproduce the results from the literature. This can be explained by the large amount of empirical parameters necessary to define one communication system and not all of them are reported in the publications. Moreover, it is rare that researchers actually share the source code of their simulator. As a consequence, a large amount of time is spent "reinventing the wheel" only to be able to compare to the state-of-the-art results

AFF3CT : Un environnement de simulation pour le codage de canal

International audienceDans cet article nous présentons un environne-ment de simulation de Monte Carlo pour les systèmes de communications numériques. Nous nous focalisons en particulier sur les fonctions associées au codage de canal. Après avoir présenté les enjeux liés à la simulation , nous identifions trois problèmes inhérents à ce type de simulation. Puis nous présentons les princi-pales caractéristiques de l'environnement AFF3CT

Lassa fever outcomes and prognostic factors in Nigeria (LASCOPE): a prospective cohort study

BACKGROUND: Lassa fever is a viral haemorrhagic fever endemic in parts of west Africa. New treatments are needed to decrease mortality, but pretrial reference data on the disease characteristics are scarce. We aimed to document baseline characteristics and outcomes for patients hospitalised with Lassa fever in Nigeria. METHODS: We did a prospective cohort study (LASCOPE) at the Federal Medical Centre in Owo, Nigeria. All patients admitted with confirmed Lassa fever were invited to participate and asked to give informed consent. Patients of all ages, including newborn infants, were eligible for inclusion, as were pregnant women. All participants received standard supportive care and intravenous ribavirin according to Nigeria Centre for Disease Control guidelines and underwent systematic biological monitoring for 30 days. Patients' characteristics, care received, mortality, and associated factors were recorded using standard WHO forms. We used univariable and multivariable logistic regression models to investigate an association between baseline characteristics and mortality at day 30. FINDINGS: Between April 5, 2018, and March 15, 2020, 534 patients with confirmed Lassa fever were admitted to hospital, of whom 510 (96%) gave consent and were included in the analysis. The cohort included 258 (51%) male patients, 252 (49%) female patients, 426 (84%) adults, and 84 (16%) children (younger than 18 years). The median time between first symptoms and hospital admission was 8 days (IQR 7-13). At baseline, 176 (38%) of 466 patients had a Lassa fever RT-PCR cycle threshold (Ct) lower than 30. From admission to end of follow-up, 120 (25%) of 484 reached a National Early Warning Score (second version; NEWS2) of 7 or higher, 67 (14%) of 495 reached a Kidney Disease-Improving Global Outcome (KDIGO) stage of 2 or higher, and 41 (8%) of 510 underwent dialysis. All patients received ribavirin for a median of 10 days (IQR 9-13). 62 (12%) patients died (57 [13%] adults and five [6%] children). The median time to death was 3 days (1-6). The baseline factors independently associated with mortality were the following: age 45 years or older (adjusted odds ratio 16·30, 95% CI 5·31-50·30), NEWS2 of 7 or higher (4·79, 1·75-13·10), KDIGO grade 2 or higher (7·52, 2·66-21·20), plasma alanine aminotransferase 3 or more times the upper limit of normal (4·96, 1·69-14·60), and Lassa fever RT-PCR Ct value lower than 30 (4·65, 1·50-14·50). INTERPRETATION: Our findings comprehensively document clinical and biological characteristics of patients with Lassa fever and their relationship with mortality, providing prospective estimates that could be useful for designing future therapeutic trials. Such trials comparing new Lassa fever treatments to a standard of care should take no more than 15% as the reference mortality rate and consider adopting a combination of mortality and need for dialysis as the primary endpoint. FUNDING: Institut National de la Santé et de la Recherche Médicale, University of Oxford, EU, UK Department for International Development, Wellcome Trust, French Ministry of Foreign Affairs, Agence Nationale de Recherches sur le SIDA et les hépatites virales, French National Research Institute for Sustainable Development

Innovation et développement dans les systèmes agricoles et alimentaires

L’innovation est souvent présentée comme l’un des principaux leviers pour promouvoir un développement plus durable et plus inclusif. Dans les domaines de l’agriculture et de l’alimentation, l’innovation est marquée par des spécificités liées à sa relation à la nature, mais aussi à la grande diversité d’acteurs concernés, depuis les agriculteurs jusqu’aux consommateurs, en passant par les services de recherche et de développement. L’innovation émerge des interactions entre ces acteurs, qui mobilisent des ressources et produisent des connaissances dans des dispositifs collaboratifs, afin de générer des changements. Elle recouvre des domaines aussi variés que les pratiques de production, l’organisation des marchés, ou les pratiques alimentaires. L’innovation est reliée aux grands enjeux de développement : innovation agro-écologique, innovation sociale, innovation territoriale, etc. Cet ouvrage porte un regard sur l’innovation dans les systèmes agricoles et alimentaires. Il met un accent particulier sur l’accompagnement de l’innovation, en interrogeant les méthodes et les organisations, et sur l’évaluation de l’innovation au regard de différents critères. Il s’appuie sur des réflexions portées par différentes disciplines scientifiques, sur des travaux de terrain conduits tant en France que dans de nombreux pays du Sud, et enfin sur les expériences acquises en accompagnant des acteurs qui innovent. Il combine des synthèses sur l’innovation et des études de cas emblématiques pour illustrer les propos. L’ouvrage est destiné aux enseignants, professionnels, étudiants et chercheurs

A tradução de narrativas autobiográficas e o ativismo político

Este projeto de tradução apresenta, numa primeira parte, a descrição e contextualização da narrativa de cariz autobiográfico The Wind in my Hair: My Fight for Freedom in Modern Iran (2018) e uma breve apresentação da sua autora, a ativista iraniana Masih Alinejad. Propõe ainda analisar de maneira comparativa e interpretativa se e como pode a tradução literária tornar-se uma forma de ativismo político e quais os possíveis impactos desse gesto. Estudam-se depois as características das narrativas de cunho autobiográfico e qual a sua relação com o ativismo (feminista). O caso prático deste projeto é naturalmente a narrativa em foco, a qual se centra sobretudo na luta da personagem principal pelos direitos das mulheres no Irão. Posteriormente este projeto propõe uma tradução de três capítulos do livro e uma subsequente análise crítica desse esforço. Espera-se dar, com este projeto, uma pequena contribuição académica de um ponto de vista social e político dentro da área dos Estudos de Tradução ao analisar um tópico, ainda pouco explorado, pelo menos no meio universitário em Portugal.This translation project presents, in a first part, the description and contextualization of the life narrative The Wind in my Hair: My Fight for Freedom in Modern Iran (2018) and a brief presentation of its author, the Iranian activist Masih Alinejad. Furthermore, it analyzes in a comparative and interpretative way if and how literary translation can become a form of political activism. The characteristics of autobiographical narratives in relation to (feminist) activism are studied as well. The practical case study is naturally the narrative presented, which portrays the struggle of the main character for women's rights in Iran. Additionally, in a second part, this project proposes a translation of three chapters of the book and its subsequent critical analysis. This project aims to make a small academic contribution from a social and political point of view within the field of Translation Studies by analyzing a topic, which is still little explored, at least within the university environment in Portugal

Prototypage d'un système de communication temps réel QCSP

National audienceIn wireless communications, frame detection and synchronization are usually performed using a preamble, consuming bandwidth and resources that are not negligible for small packets. Recently, a new kind of preamble-free frame called Quasi Cyclic Small Packet (QCSP) have been proposed. This paper present a real-time implementation of a QCSP transmission, at both transmitter and receiver sides. A credible QCSP use case is depicted. A real-world experimentation is also detailed and demonstrates that the emission/reception process of a QCSP frame is feasible at low hardware cost, which make the QCSP frame very attractive for Low Power Wide Area Networks.Dans les communications sans fil, la détection et la synchronisation des trames sont généralement effectuées à l'aide d'un préambule, ce qui consomme de la bande passante et des ressources qui ne sont pas négligeables pour les petits paquets. Récemment, un nouveau type de trame sans préambule appelé Quasi Cyclic Small Packet (QCSP) a été proposé. Cet article présente une mise en œuvre en temps réel d'une transmission QCSP, tant du côté émetteur que récepteur. Un cas d'utilisation crédible de QCSP est décrit. Une expérimentation dans le monde réel est également détaillée et démontre que le processus d'émission/réception d'une trame QCSP est réalisable à un faible coût matériel, ce qui rend la trame QCSP très attrayante pour les réseaux étendus à faible puissance

Prototypage d'un système de communication temps réel QCSP

National audienceIn wireless communications, frame detection and synchronization are usually performed using a preamble, consuming bandwidth and resources that are not negligible for small packets. Recently, a new kind of preamble-free frame called Quasi Cyclic Small Packet (QCSP) have been proposed. This paper present a real-time implementation of a QCSP transmission, at both transmitter and receiver sides. A credible QCSP use case is depicted. A real-world experimentation is also detailed and demonstrates that the emission/reception process of a QCSP frame is feasible at low hardware cost, which make the QCSP frame very attractive for Low Power Wide Area Networks.Dans les communications sans fil, la détection et la synchronisation des trames sont généralement effectuées à l'aide d'un préambule, ce qui consomme de la bande passante et des ressources qui ne sont pas négligeables pour les petits paquets. Récemment, un nouveau type de trame sans préambule appelé Quasi Cyclic Small Packet (QCSP) a été proposé. Cet article présente une mise en œuvre en temps réel d'une transmission QCSP, tant du côté émetteur que récepteur. Un cas d'utilisation crédible de QCSP est décrit. Une expérimentation dans le monde réel est également détaillée et démontre que le processus d'émission/réception d'une trame QCSP est réalisable à un faible coût matériel, ce qui rend la trame QCSP très attrayante pour les réseaux étendus à faible puissance