The 10^th International School on Signal Processing and its Applications

Prof. Abdesselam BOUZERDOUM, Hamad Bin Khalifa University (HBKU), Qatar

Presentation title: Through-the-Wall Imaging

Through-the-Wall Imaging (TWI) is an advanced sensing technology that enables the detection, localization, and imaging of objects or individuals hidden behind opaque barriers such as walls or other obstructions. Utilizing electromagnetic waves—typically in the microwave or ultra-wideband (UWB) spectrum—TWI systems exploit the penetrative capabilities of these frequencies to reconstruct scenes otherwise hidden from direct line of sight. This technology has found increasing relevance in various domains including emergency response, surveillance, security, military operations, and search-and-rescue missions. Unlike conventional radar systems, TWI must address unique challenges such as severe multipath propagation, high clutter levels, low signal-to-noise ratio (SNR), and material-dependent attenuation. These complexities demand sophisticated signal processing techniques, including synthetic aperture radar (SAR), time-reversal imaging, compressive sensing, and machine learning-based reconstruction algorithms, to achieve reliable and interpretable imaging results. This presentation introduces the fundamental principles of TWI, outlines key challenges, and highlights current trends and advancements in imaging methodologies. Particular focus is placed on recent developments in signal processing, hardware miniaturization, and data-driven approaches, all of which are shaping the next generation of robust and real-time through-the-wall imaging systems.

Prof. Karim ABED-MERAIM, University of Orleans, France

Presentation title: Extremely Large Antenna Arrays (ELAA) For 6G Communications & Sensing

Extremely Large Antenna Arrays (ELAA) are recognized as a key enabling technology for 6G networks. By deploying hundreds or even thousands of antennas at base stations, ELAA can dramatically enhance system performance. In the context of 6G, ELAA not only entails a substantial increase in antenna count but also brings about fundamental changes in electromagnetic field behavior. Electromagnetic radiation is typically categorized into far-field and near-field regions, with the dividing line defined by the Rayleigh distance-a value that scales with the square of the array aperture and the carrier frequency. With the anticipated increase in both antenna count and carrier frequency in 6G systems, the near-field region of ELAA is expected to expand significantly. As a result, near-field communication is emerging as a critical aspect of 6G and has garnered growing research attention in recent years. This fundamental shift in electromagnetic field behavior introduces both challenges and new opportunities for ELAA systems. On the one hand, traditional wireless communication theories based on far-field assumptions may experience significant performance degradation. On the other hand, near-field propagation offers new advantages, such as improved signal strength at targeted receivers and an additional degree of freedom in the distance domain, potentially boosting spectrum efficiency. This talk is about introducing basic concepts on near-field communications, and their challenges and opportunities. We will also present some recent works about channel estimation and mobile positioning using ELAA with blind and semi-blind techniques.

Prof. Adel BELOUCHRANI, Ecole Nationale Polytechnique, Algeria

Presentation title: How to conduct research in signal processing?

The lecture will try to answer the following questions: What should be the main motivation when one engages in scientific research? In general, what research in signal processing is about? How should one conduct bibliographic search? Why an academic researcher should publish? and what are the main motivations? What are the keys for a successful writing? What are the main questions that the author should answer while writing his paper? How to choose an appropriate journal to which one will submit the finished paper for publication? What would be the mean advice to have a paper with a clear storyline? Why are papers rejected? How would an author reply to the reviewer’s comments? …

Other issues related to the PhD candidate communication with his supervisor will also be discussed.

Prof. Mohammed Nabil EL KORSO, Paris Saclay University, France

Presentation title: A Journey from Maximum Likelihood to Variational Auto-encoders, with a Stop at Expectation-Maximization Framework

This lecture invites participants on a conceptual journey through probabilistic inference and latent variable modelling. We begin with the classical framework of Maximum Likelihood Estimation (MLE), the foundational pillar for parameter estimation in probabilistic models. Building on this, we revisit the Expectation-Maximization (EM) algorithm, a powerful iterative method for dealing with hidden data, highlighting its elegance and limitations in high-dimensional and complex systems. Our journey continues into the modern era of deep generative models with Variational Autoencoders (VAEs), where we explore how the principles of the EM naturally evolve within a variational inference framework. Special attention will be given to how VAEs approximate intractable posterior distributions and how this connects back to the EM philosophy. Throughout the lecture, applications in sensing and communication systems will be considered.

Prof. Ammar MESLOUB, Ecole Militaire Polytechnique, Algeria

Presentation title: Introduction to Ultra-Wide Band (UWB) signal processing

The aim of this presentation is to introduce definitions and preliminaries used for UWB signal processing techniques. Firstly, we give a presentation and definition of different kind of signals as narrow band, wide band and UWB. Then, we specify the used UWB signals and their modulations. Secondly, we introduce the time and frequency presentations and how the last presentation is obtained. Thirdly, we have chosen radar applications using UWB signal. The first application is DOA finding and the second application is the frequency back-projection algorithm in SAR scenario improved by wavelet transform.

Prof. Abdelmadjid MAALI, Ecole Militaire Polytechnique, Algeria

Presentation title : IR-UWB Radar for human respiration detection: principles and application

Human respiratory activity is a vital physiological parameter with significant relevance in healthcare, security, and search-and-rescue operations. To overcome the limitations of traditional contact-based techniques, Impulse Radio Ultra-Wideband (IR-UWB) radar has emerged as a promising alternative, offering high resolution, strong penetration capability, and reliable non-contact operation. In this presentation, we first address the principle of respiration detection using IR-UWB radar. The method relies on capturing the minute chest wall displacements caused by inhalation and exhalation, which manifest as periodic modulations in the radar signal. These variations are organized within a radar matrix used to accurately estimate the respiratory rate. Next, we examine the generation of IR-UWB signals, which can be achieved through analog RF circuits, digital logic, or programmable platforms such as FPGAs. Two main categories of IR-UWB signals are highlighted: those with a fixed pulse repetition interval (PRI) and those based on chaotic pulse position modulation (CPPM). Finally, we present the signal processing chain for vital sign estimation. Following transmission and reception through UWB antennas, the radar data are sampled at high frequency and processed to suppress undesired components, enhance respiratory echoes, and apply estimation methods such as correlation and higher-order cumulants. These steps enable precise extraction of both respiratory frequency and target position.

Dr. Djamel TEGUIG, Ecole Militaire Polytechnique, Algeria

Presentation title: Spectrum Sensing: Modeling and SDR Implementation

Spectrum sensing is a fundamental component of cognitive radio systems, enabling dynamic access to underutilized frequency bands and improving spectrum efficiency. This course provides a comprehensive overview of spectrum sensing, covering its theoretical foundations, signal modeling techniques, and practical implementation using software-defined radios (SDRs). Participants will explore key detection techniques, such as energy detection, matched filtering, and cyclostationary analysis, and evaluate their performance under real-world conditions.

The course also addresses current and emerging applications in wireless communications, including dynamic spectrum access, wireless communications, IoT, and public safety networks. A significant portion is dedicated to hands-on SDR programming, where students will use tools like GNU Radio, UHD, and IT++ to implement and test spectrum sensing algorithms on hardware platforms such as the USRP B210. By the end of the course, attendees will gain both a deep theoretical understanding and practical skills necessary to develop and evaluate spectrum sensing systems. The course will also highlight recent advances and explore new research directions in spectrum sensing, aiming to inspire innovative approaches and applications.