Alexandru Takacs

Battery-free Wireless Sensors used for IoT applications
E-mail: atakacs@laas.fr

Abstract: This paper highlights the new advances in the field of energy-autonomous battery-free wireless sensors for IoT applications. The design and implementation challenges as well as optimized solutions are presented in a unified approach. At device level, the most relevant hardware architectures are presented with a focus of state-of-art experimental results obtained for battery-free LoRaWAN (Long Range Wide Area Network) and BLE (Bluetooth Low Energy) wireless sensors targeting IoT (Internet of Things) and SHM (Structure Health Monitoring) applications. At system level we are focusing on networks topologies and new security and identification mechanisms implemented on hardware/electromagnetic level by exploiting the power transfer link capabilities in the context of the simultaneously wireless information and power transfer.

Cornel Ioana

Signal Processing using Phase Diagram Analysis - New Perspectives in Understanding Transient Features in Data Science
E-mail: cornel.ioana@gipsa-lab.grenoble-inp.fr

Abstract: In our current world, the digital progress is visible in continuous and intensive communications, cloud computing, artificial intelligence and big data making these techniques part of our professional and life style. Among fundamental topics related to these techniques the data science is the main multi-disciplinary domain that offers a large panel of approaches for data processing and data-based decision making in all applications of nowadays world: multimedia, computer science, engineering, science, finance.
In the data analysis transient phenomena are of increasing interest since they are always revealing details about the processes and especially how they changes. Analyzing properly the transients can be very useful to understand the variation in the data structures and depict behaviors of great importance for the proper decision making. The increasing interest for transient analysis conducts to new and performant approaches falling in two main categories: energy-based techniques and model-based analysis.
An alternative to these two broad classes of transient phenomena characterization is the phase diagram analysis. This method traditionally employed in the study of dynamical systems has recently emerged as a powerful tool for analyzing transient features in signal processing. This method, which graphically represent the trajectories of system states over time, offer a unique approach to uncovering underlying patterns and transient behaviors that conventional signal processing methods might overlook. By mapping the analyzed signals into a phase diagram domain, transient features such as sudden changes, anomalies, and oscillations become more discernible. Being a data-driven analysis method, this advantage gives it the possibility to be useful in many different fields.
In the domain of communication field, the phase diagram analysis can be used to detect and characterize transient signals in wireless communications. This brings many benefits in the process of characterization, classification and recognition of the types of intercepted modulations. These insights can significantly improve the robustness and reliability of communication systems.
In the energy sector, the phase diagram analysis can assists in monitoring the transient behavior of the power grid. This approach allows the realization of a complete predictive maintenance of power networks, having a variety of applications, such as: detection of early phenomena specific to cable degradation, localization of defect sources, risk assessment and so on.
In the high frequencies and THz domain, the phase diagram analysis can reveal transient phenomena in high-frequency signal processing. This is particularly relevant for the development of advanced imaging and sensing technologies, where understanding transient features can lead to improved resolution and sensitivity. By using this method, we gain new insights into transient features, driving advancements in communication, energy management, and THz technology.

Arun DEEPAK

Tunable Graphene Reinforced Sensors And Antennas

Abstract: Nano materials play a significant role in modern engineering and medical practices. Graphene is appreciated due to its extraordinary electrical and transport properties. Nanomaterial reinforced polymer matrix based thin films find wide range of applications in the field of electronics and various sensors.
This research work primarily explores the non-destructive strain sensing property of graphene-PVDF (Polyvinylidene fluoride) film using Raman analysis and Raman mapping. Secondly, the conductivity nature of different weight percentage of graphene-PVDF films were measured and the possibility of using it as inset fed conductive patch in micro-strip patch antennae were also explored.
Different weight percentages of graphene-PVDF films were prepared using solvent casting technique. All the weight percentage of graphene- PVDF films were subjected to five different strain levels (say 5, 10, 15, 20, 25) of maximum strain limit by attaching the films to (American standard of Testing Material) ASTM specimen using Universal Testing Machine (UTM).
Raman analysis of different weight percentage of Graphene-PVDF films were carried out. ID/IG ratio for all the strain level of each film were calculated. Calibration curve representing ID/IG ratio along y-axis and strain values along x-axis were drawn for different weight percentage of the film. Standardization of strain sensing can be achieved based on the calibration graph obtained. It can be used as a prediction technique to find out unknown strain value by measuring ID/IG ratio using Raman

Roland GAUTIER

A Synchronization Front-End for LoRa Self-Jamming Operation on SDR Platforms
E-mail: roland.gautier@univ-brest.fr

Abstract: We proposed a LoRa self-jamming scheme that enables secure and covert communications by adding jamming symbols when transmitting. These jamming symbols are perfectly known by both the legitimate transmitter and receiver, but not by a potential eavesdropper. This puts strong demodulation difficulties for the latter, but offers good demodulation capability for the legitimate receiver. The scheme has been validated in simulations. This article continues the previous work by validating the scheme on real-world Software Defined Radio (SDR) equipment. We develop in that sense a dedicated synchronization frontend, crucial part of the receiver to enable proper demodulation. Each step of the front-end is detailed and results from SDR transmissions are provided to assess demodulation ability. Results show proper demodulation of the transmitted symbols and very good adequacy between expected and actual front-end behavior on SDR. This paves the way for real-world application of the LoRa self-jamming scheme.