A Walsh-Based Arbitrary Waveform Generator for 5G Applications in 28nm FD-SOI CMOS Technology

This paper presents the first Arbitrary Waveform Generator (AWG) based on Walsh’s theory for wideband radio frequency (RF) conversion. The architecture is dedicated to 5G-FR1 applications (sub-6GHz) to perform a direct and large bandwidth conversion while achieving the highest energy efficiency. The circuit generates Walsh sequences weighted by Walsh coefficients thanks to dedicated Digital-to-Analog Converters (DACs). It embeds an internal memory to feed the data to be converted for measurement purposes. The sum of the weighted Walsh sequences carries out RF signals made of intrinsically synchronous aggregated channels over a frequency range between 600 MHz and 4 GHz. A high-level simulation study is performed as well as transistor-level simulation including post-layout and Monte-Carlo analysis. The circuit is designed in 28nm FD-SOI CMOS technology from STMicroelectronics. The power consumption is 44 mW depicting an energy per bit of 0.34 pJ/bit, the lowest of the state of the art to the authors’ knowledge

Thermalizing a telescope in Antarctica: Analysis of ASTEP observations

The installation and operation of a telescope in Antarctica represent particular challenges, in particular the requirement to operate at extremely cold temperatures, to cope with rapid temperature fluctuations and to prevent frosting. Heating of electronic subsystems is a necessity, but solutions must be found to avoid the turbulence induced by temperature fluctua- tions on the optical paths. ASTEP 400 is a 40 cm Newton telescope installed at the Concordia station, Dome C since 2010 for photometric observations of fields of stars and their exoplanets. While the telescope is designed to spread star light on several pixels to maximize photometric stability, we show that it is nonetheless sensitive to the extreme variations of the seeing at the ground level (between about 0.1 and 5 arcsec) and to temperature fluctuations between --30 degrees C and --80 degrees C. We analyze both day-time and night-time observations and obtain the magnitude of the seeing caused by the mirrors, dome and camera. The most important effect arises from the heating of the primary mirror which gives rise to a mirror seeing of 0.23 arcsec K--1 . We propose solutions to mitigate these effects.Comment: Appears in Astronomical Notes / Astronomische Nachrichten, Wiley-VCH Verlag, 2015, pp.1-2

Walsh-Domain Neural Network for Power Amplifier Behavioral Modelling and Digital Predistortion

This paper investigates the use of Neural Network (NN) nonlinear modelling for Power Amplifier (PA) linearization in the Walsh-Hadamard transceiver architecture. This novel architecture has recently been proposed for ultra-high band width systems to reduce the transceiver power consumption by extensive parallelization of the digital baseband hardware. The parallelization is achieved by replacing two-dimensional quadra ture modulation with multi-dimensional Walsh-Hadamard mod ulation. The open research question for this architecture is whether conventional baseband signal processing algorithms can be similarly parallelized while retaining their performance. A key baseband algorithm, digital predistortion using NN models for PA linearization, will be adapted to the parallel Walsh architecture. A straighforward parallelization of the state-of-the-art NN archi tecture is extended with a cross-domain Knowledge Distillation pre-training method to achieve linearization performance on par with the quadrature implementation. This result paves the way for the entire baseband processing chain to be adapted into ultra high bandwidth, low-power Walsh transceivers. Index Terms—digital predistortion (DPD), power amplifier(PA), time-delay neural network (TDNN), Walsh-Hadamard transform

Distributed Intelligent Integrated Sensing and Communications: The 6G-DISAC Approach

This paper introduces the concept of Distributed Intelligent integrated Sensing and Communications (DISAC), which expands the capabilities of Integrated Sensing and Communications (ISAC) towards distributed architectures. Additionally, the DISAC framework integrates novel waveform design with new semantic and goal-oriented communication paradigms, enabling ISAC technologies to transition from traditional data fusion to the semantic composition of diverse sensed and shared information. This progress facilitates large-scale, energy-efficient support for high-precision spatial-temporal processing, optimizing ISAC resource utilization, and enabling effective multi-modal sensing performance. Addressing key challenges such as efficient data management and connect-compute resource utilization, 6G- DISAC stands to revolutionize applications in diverse sectors including transportation, healthcare, and industrial automation. Our study encapsulates the project vision, methodologies, and potential impact, marking a significant stride towards a more connected and intelligent world.Comment: Submitted for conference publicatio

Autoantibodies against type I IFNs in patients with life-threatening COVID-19

Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men

Vascular and blood-brain barrier-related changes underlie stress responses and resilience in female mice and depression in human tissue

Prevalence, symptoms, and treatment of depression suggest that major depressive disorders (MDD) present sex differences. Social stress-induced neurovascular pathology is associated with depressive symptoms in male mice; however, this association is unclear in females. Here, we report that chronic social and subchronic variable stress promotes blood-brain barrier (BBB) alterations in mood-related brain regions of female mice. Targeted disruption of the BBB in the female prefrontal cortex (PFC) induces anxiety- and depression-like behaviours. By comparing the endothelium cell-specific transcriptomic profiling of the mouse male and female PFC, we identify several pathways and genes involved in maladaptive stress responses and resilience to stress. Furthermore, we confirm that the BBB in the PFC of stressed female mice is leaky. Then, we identify circulating vascular biomarkers of chronic stress, such as soluble E-selectin. Similar changes in circulating soluble E-selectin, BBB gene expression and morphology can be found in blood serum and postmortem brain samples from women diagnosed with MDD. Altogether, we propose that BBB dysfunction plays an important role in modulating stress responses in female mice and possibly MDD

Contribution à l'étude et à la réalisation d'un frontal radiofréquence analogique en temps discrets pour la radio-logicielle intégrale

Many technological bottlenecks prevent from realizing a Software Radio (SR) mobile terminal. The old way of building radio architectures is over due to the numerous communication standards a single handeld terminal have to address nowadays. This thesis exposes a disruptive SR receiver: a Sampled Analog Signal Processor (SASP) is designed and brought into play to perform downconversion and channel presort. It processes analog voltage samples in order to recover in baseband any RF signal emitted from 0 to 5GHz. An analog Fast Fourier Transform achieves both frequency shifting and filtering. A prototype using 65nm CMOS technology from STMicroelectronics is here presented and measured.Le concept de Radio Logicielle propose d'intégrer en un seul circuit un émetteur / récepteur RF capable d'émettre et de recevoir n'importe quel signal RF. Cependant, ce concept doit affronter des contraintes technologiques dans le cas des terminaux mobiles. La contrainte principale est la consommation de puissance du terminal. En effet, la conversion analogique numérique qui est la clé de ce système en est aussi le principal verrou technique. Cette thèse présente une architecture de récepteur en rupture avec les architectures classiques afin de surmonter le problème de la conversion analogique numérique. Il s'agit d'un processeur analogique de traitement du signal dédié à la Radio Logicielle intégrale dans la gamme de fréquence 0 à 5GHz. Sa conception et les mesures d'un prototype sont présentées

Design by Mathematics : A Novel Approach for the Design of RFICs in Nanoscale CMOS: Advanced concepts for future RF and mmW transceivers in nanoscale CMOS

International audienceWith the advent of nano-scale CMOS technology, exciting new developments have recently taken place in the field of RF and mm-wave transmitters, receivers and frequency synthesizers. The low-voltage, fast speed, fine feature-size and low cost of the new technology have forever changed the way we design circuits, architectures and systems. Not only the RF/mm-wave circuits have taken different shapes from what has been taught in textbooks but also their integration with digital processors have enabled new possibilities for digital assistance, offering autonomous built-in self-testing and self-calibration. This workshop gives an overview and samples of such latest developments