arXiv subjects

Thierry Clessienne

Publications and source records attributed to Thierry Clessienne.

2 recordsLinked to original sources

arXiv2024

Inter-RIS Beam Focusing Codebook Design in Cooperative Distributed RIS Systems

This paper explores distributed Reconfigurable Intelligent Surfaces (RISs) by introducing a cooperative dimension that enhances adaptability and performance. It focuses on strategically deploying multiple RISs to improve connectivity with the Base Station (BS) and among RISs, thereby aiding users in areas with weak BS coverage and enhancing spatial multiplexing gains. Each RIS can function as a primary surface to directly support users or as an intermediary surface to reflect signals to another primary surface. This dual functionality enables flexible responses to changing conditions. We implement an inter-RIS signal focusing design for phase shifts, creating a tailored codebook for precise control over signal direction. This design considers the interplay of incidence and reflection angles to maximize reflected signal power, based on the RIS response function and the physical properties of the RIS elements.

eess.SP↗

arXiv2018

Exploiting Location Information to Enhance Throughput in Downlink V2I Systems

Vehicle-to-Infrastructure (V2I) technology, combined with millimeter wave (mmW) networks, may support high data rates for vehicular communication and therefore provides a whole new set of services. However, in dense urban environment, pedestrians or buildings cause strong blockage to the narrow beams at mmW, severely deteriorating the transmission rate. In this work, we model the downlink mmW V2I system as a simple erasure broadcast channel where the erasure (blockage) event is considered as the state of the channel. While state feedback can be obtained through protocols such as Automatic Repeat reQuest (ARQ), we also assume that the current state can be estimated through the location information shared by the communication peers. We evaluate, through an information-theoretic approach, the achievable downlink rate in such a system. Despite its highly theoretical nature, our result sheds light on how much the location information can contribute to improve the downlink date rate, e.g., as a function of the mobility (velocity) of the vehicles.

cs.IT↗