Shannon Wireless

This work addresses these challenges by introducing an optimization framework for #Stacked #Intelligent #Metasurfaces (#SIM) that, unlike previous approaches, is based on a comprehensive model without relying on specific assumptions, allowing for broader applicability of the results. The authors first present a model based on #multi-#port #network theory for characterizing a general #electromagnetic #collaborative #object (#ECO) and derive a general framework for ECO optimization. They then introduce the SIM as an ECO with a specific architecture, providing insights into SIM optimization for various architectures and discussing the complexity in each case. Finally, they analyze the impact of commonly used assumptions, demonstrating that employing a complete model - one that does not rely on the unilateral hypothesis and accounts for mutual coupling among SIM elements - can yield better performance, using the realization of a #2D #DFT as a case study. ---- Andrea Abrardo,?Giulio Bartoli,?Alberto Toccafondi More details can be found at this link: https://lnkd.in/g8nB23Qb

Reconfigurable intelligent surface (RIS) is a revolutionary technology that can customize the wireless channel and improve the energy efficiency of next-generation cellular networks. This letter proposes an environment-aware codebook design by employing the statistical #channel #state #information (#CSI) for #reconfigurable #intelligent #surface (#RIS)-#assisted #multiple-#input #single-#output (#MISO) systems. Specifically, first of all, the authors generate multiple virtual channels offline by utilizing the location information and design an environment-aware #reflection #coefficient #codebook. Thus, they only need to estimate the composite channel and optimize the active #transmit #beamforming for each reflection coefficient in the pre-designed codebook, while simplifying the reflection optimization substantially. Moreover, they analyze the theoretical performance of the proposed scheme. ---- Xing Jia;?Jiancheng An;?Hao Liu;?hongshu Liao;?Lu Gan;?Chau Yuen More details can be found at this link: https://lnkd.in/gj8Un--S

In this work, the authors propose the use of #Gaussian #processes (#GPs) together with #in-#situ, #EO and #ERA-#Interim climate reanalysis data for crop yield forecasting. Country-level agricultural survey data from #FAOSTAT are used for quantitative assessment. The study is conducted in the framework of the #ASAP (#Anomaly #hot #Spots #of #Agricultural #Production) early warning decision support system of the European Commission, which aims at providing timely information about possible crop production anomalies worldwide. ---- Maria Piles;?Anna Mateo Sanchis;?Jordi Martí Mu?ozí;?Gustau Camps-Valls;?Fran?ois "Franz" Waldner;?Felix Rembold; Michele Meroni More details can be found at this link: https://lnkd.in/gswRGpnw

In this correspondence, the authors propose #hierarchical #high-#altitude #platform (#HAP)-#low-#altitude #platform (#LAP) networks with the aim of maximizing the sum-rate of ground #user #equipments (#UEs). The multiple aerial radio units mounted on HAPs and LAPs are managed by the #central #unit (#CU) via constrained #fronthaul #links. The limitation of fronthaul capacity can be addressed through quantization, employing the network #multiple-#input #multiple-#output (#MIMO) architecture. For spectral efficiency, they adopt the #rate-#splitting #multiple #access (#RSMA), leveraging the advantages of both #space-#division #multiple #access (#SDMA) and #non-#orthogonal #multiple #access (#NOMA). To achieve this, they jointly optimize multiple-antenna rate-splitting transmission, fronthaul quantization design and #UAV placement using an #alternating #optimization (#AO) approach coupled with #successive #convex #approximation (#SCA) and the #weighted #minimum #mean #square #error (#WMMSE) method. Numerical results validate the superior performance of the proposed method compared to benchmark schemes, including partial optimizations or those without the assistance of LAPs. ---- Jeongbin Kim;?Seongah Jeong;?Seonghoon Yoo;?Son Woong;?Joonhyuk Kang More details can be found at this link: https://lnkd.in/gyp7u7cK

In this paper, a #visible #light #communication (#VLC) system for #indoor #Internet #of #Things (#IoT) applications, called #VLCIoT, is proposed. The proposed system is based on type I of the #IEEE 802.15.7 standard #physical (#PHY) layer. The PHY I is provided for low data rate applications from 10 to 100?kb/s, which looks suitable for the typical IoT applications. The #on-#off #keying suggested modulation scheme by the PHY I that is simple and requires low-cost hardware for implementation is considered. The implemented VLCIoT system is robust against indoor ambient light interference. Using the frequency division multiple access, several VLC networks can operate at different frequencies in the vicinity of each other without interference. The data rate of VLCIoT is up to 115.2?kb/s, and the #bit #error #ratio of the system is very low. This system is designed for indoor, which for this purpose operates well up to 7?m distances. In this paper, a #figure #of #merit (#FoM) is proposed, in which the most important parameters for IoT applications are considered. A comprehensive comparison of VLCIoT to other suitable VLC systems for IoT applications is performed. The results show that the VLCIoT achieves the best FoM and is suitable for indoor IoT applications. ---- Armin Makvandi, Yousef Seifi Kavian, Ehsan Namjoo More details can be found at this link: https://lnkd.in/g95s-C2g

This paper provides a technique for the protection of image in open wireless channel. It depends on #steganography and #cryptography (#double #random #phase #encoding). In this method primary step is to cover a message image inside an another image through steganography to make a stego image and then a simple encoding technique; #double #random #phase #encoding (#DRPE) is perform on stego image. For the evaluation of proposed technique, statistical tests like entropy, time analysis and #peak #to #signal #noise #ratio (#PSNR) with and without noises (#Gaussian, #salt #n #pepper and #speckle) are performed which illustrate that the proposed technique provide better security to the transmitted image in wireless channel than the other techniques. ---- Sadaf Bukhari;?Muhammad Shoaib Arif;?M.R. Anjum;?Samia Dilbar More details can be found at this link: https://lnkd.in/gfmEy-ug

This paper equivalently transform #stacked #intelligent #metasurface (#SIM) downlink transmission resource allocation problem to a #Markov #decision #process (#MDP) form. Next, the authors train an #asynchronous #advantage #actor #critic (#A3C) agent on the MDP-reformulated problem for optimizing the #transmit #power of the #base #station (#BS) and the electromagnetic response of the SIM, in a joint fashion. Subsequently, by taking into account the mobility of terminals, they further enrich the adaptability of the trained A3C agent via #meta-#learning. It is numerically revealed that incorporating SIM leads to an approximate 30% enhancement in the energy efficiency of existing #simultaneous #wireless #information #and #power #transfer (#SWIPT) systems. ---- Mojtaba Amiri, Sepideh Javadi, Hosein Zarini, Mohammad Robat Mili, Jiancheng An, Mehdi Sookhak, Ioannis Krikidis More details can be found at this link: https://lnkd.in/egzavYfv

In this paper, the authors provide a comprehensive overview of these emerging intelligent #metasurface #technologies. They commence by examining recent experiments of #reconfigurable #intelligent #surfaces (#RIS) and exploring its applications from four perspectives. Furthermore, they delve into the fundamental principles underlying #stacked #intelligent #metasurfaces (#SIM), discussing relevant prototypes as well as their applications. Numerical results are also provided to illustrate the potential of SIM for analog signal processing. Finally, they review the state-of-the-art of #flexible #intelligent #metasurface (#FIM) technology, discussing its impact on wireless communications and identifying the key challenges of integrating FIMs into wireless networks. ---- Jiancheng An, Merouane Debbah, Tie Jun Cui, Zhi Ning Chen, Chau Yuen More details can be found at this link: https://lnkd.in/eZQTvjf4

In this study, the authors design an #Intelligent #Soft #Handover for #unmanned #aerial #vehicle (#UAV)-enabled cellular networks (#IntSHU), a #generative #adversarial #network (#GAN)-based scheme designed for intelligent soft handovers in UAV-enabled 5G and beyond. IntSHU uses #adapted #hysteresis #margins and #time-#to-#trigger (#TTT) values, dynamically generated through an -#greedy #policy. In addition, they implement a lightweight, #physically #unclonable #function (#PUF)-based message encryption and authentication scheme via blockchain for streamlined access control during handovers. ---- Raja Karmakar, Georges Kaddoum, Ouassima Akhrif More details can be found at this link: https://lnkd.in/d7EZ-eW2

The authors introduce #Wireless #Peering for #cellular #providers, a concept inspired by #ISP peering in wireline networks. By facilitating settlement-free #spectrum #sharing, Wireless Peering allows providers to seamlessly extend their coverage to #off-#network #regions, without any hardware modifications. Due to its software-defined nature, the model offers high scalability, cost-effectiveness and ease of deployment. In this paper, they detail the core ideas and operational framework of a Wireless Peering model with a particular emphasis on improving customer satisfaction and provider revenue gains. ---- Anindo Mahmood, Shahzeb Mustafa, Murat Yuksel, Sayanta Seth, Ph.D, Mostafizur Rahman More details can be found at this link: https://lnkd.in/dNwz3tXT