Détection et Communication Intégrées dans les Réseaux sans Fil : Formation de Faisceaux Holographiques et Détection avec les Signaux 5G NR

Integrated sensing and communication (ISAC) is expected to play a crucial role in sixth-generation (6G) and beyond networks, driven by applications like intrusion detection, UAV flight support, IoT, and autonomous driving. ISAC generally falls into three scenarios: Monostatic, Bistatic, and Multistatic, each posing unique challenges. This PhD research investigates these scenarios to address key challenges.The first part of the thesis develops a model for dynamic metasurface antennas (DMAs), evaluating their performance as an alternative to traditional MIMO systems in monostatic ISAC. The second part explores the potential challenges of leveraging the existing infrastructure of fifth-generation (5G) New Radio (NR) signals and resources, as defined by the 3rd Generation Partnership Project (3GPP), in bistatic, and multistatic ISAC, minimizing network modifications while optimizing resources.Chapter 1 introduces ISAC concepts, emphasizing its role in future wireless networks and discussing 3GPP standardization efforts, KPIs, intelligent metasurfaces, and their contributions to ISAC.Chapter 2 presents an electromagnetic analysis of the DMA model, considering factors like backscattering, wave attenuation, and mutual coupling. Closed-form expressions characterize the interactions between RF chains, DMA elements, and receivers, forming the basis for a narrowband communication system and beamforming algorithm in Chapter 3.Chapter 3 explores monostatic ISAC using the DMA model from Chapter 2, improving simulation accuracy. A holographic beamforming optimization problem is formulated to maximize beampattern gains while meeting SINR requirements. An optimization algorithm is proposed and its convergence is proven.Chapter 4 examines the use of 5G NR signals in bistatic ISAC, addressing three challenges: range and Doppler ambiguity, resource allocation, and spectral efficiency. The proposed approaches eliminate ambiguities and reduce interference, demonstrating the feasibility of superimposing communication and sensing symbols within an OFDM resource grid under 3GPP constraints.Chapter 5 focuses on improving localization accuracy in multistatic ISAC with 5G NR signals. A novel algorithm is introduced to mitigate outlier effects in range measurements which accounts for sensing signal resolution errors. Simulations show its superiority over previous methods, paving the way for advanced sensing in future networks.Finally, Chapter 6 summarizes key contributions and outlines future research directions.