Design and analysis of a reconfigurable intelligent meta-surface for vehicular networks

International audienceIn this work, a new paradigm for vehicular communications based on Reconfigurable Intelligent Meta-surfaces (RIMs) is presented. By using the proposed RIM, we are able to manipulate electromagnetic waves in the half-space, since the element is reflective. The unit cell consists of a U-shaped designed microstrip structure equipped with a pin diode and via a hole. In this study, two different reflection modes are achieved for 1-bit data transferring in each state. By incorporating these two different configurations together, the reflected phases in the proposed RIM surface can be controlled respectively in 0 ∘ and 180 ∘. The proposed unit cell can provide a usable double negative functional characteristic around 5.3 GHz. The main goal of this paper is the use of a multifunctional behavior RIM for vehicular communications to code the transmitted wave. A novel phase distribution diagram is generated to propagate in each angle. Moreover, two major electromagnetic modulation functions, beam forming and space coding have been demonstrated. Finally, we show how the RIM can be employed for vehicular communications, acting as a coated access point along the street. We derive the instantaneous data rate at the receiver node, the outage probability and the channel capacity, as affected by different beam widths, distances and vehicle speed

Analysis of the Chirality Effects on the Capacity of Wireless Communication Systems in the THz band

International audienceThe potentialities of Terahertz frequency band in the context of nano-scale communications are largely increasing, thanks to specific features that allow to overcome the issues related to the spectrum scarcity and capacity limitation. Apart from high molecular absorption and very high reflection loss that represent the main phenomena in Terahertz (THz) band, in this paper we investigate the chirality effects that affect the propagation medium, in the frequency range (4 − 10) THz. It is observed that in this interval the chiral parameter shows resonance peaks in specific frequencies. In this paper we investigate the channel capacity in a special medium affected by chirality effects, such as biomolecules, DNA chains, etc. Specifically, we analyze the signal propagation in a chiral medium where a Giant Optical Activity (GOA) is present. This effect is typical of the so-called chiral-metamaterials. Through simulation results we distinguish the behavior of a chirality-affected channel with GOA in Line-of-Sight and Non-Line-of-Sight propagations, assuming different power allocation techniques and also comparing the performance to the case of No GOA