Shannon Wireless

This paper developed a novel #hybrid #digital-#wave #domain #channel #estimator, in which the received training symbols are first processed in the wave domain within the #stacked #intelligent #metasurface (#SIM) layers, and then processed in the digital domain. The wave domain channel estimator, parametrized by the phase shifts applied by the meta-atoms in all layers, is optimized to minimize the #mean #squared #error (#MSE) using a gradient descent algorithm, within which the digital part is optimally updated. For an SIM-enabled multi-user system equipped with 4 RF chains and a 6-layer SIM with 64 meta-atoms each, the proposed estimator yields an MSE that is very close to that achieved by fully digital #channel #estimation (#CE) in a massive MIMO system employing 64 RF chains. This high CE accuracy is achieved at the cost of a training overhead that can be reduced by exploiting the potential low rank of channel correlation matrices. ---- Qurrat-Ul-Ain Nadeem, Jiancheng An, Anas Chaaban More details can be found at this link: https://lnkd.in/gwAAKgWR

This paper addresses several critical issues in #dynamic #spectrum #sharing (#DSS). Firstly, the authors investigate #resource #block (#RB) allocation in a multi-cell environment, considering #inter-#cell #interference (#ICI) and #frequency #reuse (#FR) to optimize the combined #long-#term #evolution (#LTE) and #new #radio (#NR) data rates in a DSS-enabled network. They then apply #maximum #throughput (#MT) and #enhanced #proportional #fairness (#ePF) schedulers for RB allocation within their proposed simulation framework. Additionally, they explore the impact of satisfying users #quality #of #service (#QoS) on data rate and fairness across various sharing ratio values for LTE and NR #guaranteed #bit #rate (#GBR) users. ---- Marziyeh Karkhaneh, Sajedeh Norouzi, Mohammadreza Abedi, Nader Mokari, Mohammad R. Javan, Hamid Saeedi, Eduard Jorswieck More details can be found at this link: https://lnkd.in/eRyqErB5

In this paper, the authors describe the planning and execution of #Electromagnetic #Fields (#EMF) measurements in Luxembourg and the lessons learned from that process. They describe the specifics of Luxembourg, how the pilot sites as well as the measuring devices have been selected. They also discuss the results of the measurements from fixed and mobile devices, with regard to the regulatory limits. Finally, they describe the facts that limit the short-term deployment of devices and the difficulties to measure 5G exposition. All the datasets collected for this study are proposed as open-source format. ---- Uwe Roth, Lamia Selmane, Sébastien Faye More details can be found at this link: https://lnkd.in/et7T7THi

This paper proposes the usage of #conformal #metasurfaces (#C-#RIS or #C-#IRS) deployed on vehicles’ body to mitigate the blockage impact by creating artificial reflections, compensating for the non-flat shape of the vehicle’s body with proper phase patterns. We analytically derive the phase pattern for a cylindrical C-RIS/C-IRS, accounting for the shape of the car body, which generalizes the conventional planar ones. We propose a novel design for optimally pre-configured C-IRS proving its benefits in a #vehicle-#to-#vehicle (#V2V) highway scenario. The traffic simulation results show a reduction of blockage probability by 20% for C-IRS and 70% for C-RIS as a benchmark, as well as a remarkable improvement in average signal-to-noise ratio by 10–20 dB for C-IRS and 30–40 dB for C-RIS. ---- Marouan Mizmizi, Reza Aghazadeh, Dario Tagliaferri, Kai Dong, Gian Guido Gentili, Umberto Spagnolini More details can be found at this link: https://lnkd.in/eFncVUhz

In this work, a low-profile center-fed #leaky-#wave #antenna (#LWA) is proposed, which combines the full-space beam-scanning capabilities of transmitarrays and the low-profile nature of LWAs. A #true-#time-#delay (#TTD) phase-shifting mechanism is used, where a variable length stripline inside the unit cell yields more than 540° of phase range. The 2564-element array generates a pencil beam that may be designed for steering to arbitrary angles. A gain of 27.8 dBi is measured at broadside, while this value measures 22.2 dBi at the representative off-broadside angle of?θ0=30°?at the design frequency of 19.5 GHz. The proposed antenna is low profile, with a thickness of 1.6 mm (approximately?λ/10 at the design frequency) mounted on top of a radial feed waveguide possessing an 8 mm (approximately?λ/2) height. ----- Elham Baladi, Gursimran Singh Sethi, Hervé Legay, Sean Victor Hum More details can be found at this link: https://lnkd.in/eibfzKyd

In this article, they showcase how #deep #reinforcement #learning (#DRL) can jointly address the problems of blockage and #mobility in #millimeter #wave (#mmWave) ad #hoc #networks. They first summarize the problem of relay selection with realistic over-head penalties in which the beam management training time is characterized and minimized through a #sequential #decision-#making approach. They then describe how #hierarchical #learning can be leveraged for choosing between distinct frequency bands for communication by addressing the issues posed by differing precoding training procedures. They conclude by overviewing how #learning #algorithms will be an important tool to overcome the challenges faced by future ad hoc networks.----Dohyun Kim, @Miguel Castellanos, Robert Heath More details can be found at this link: https://lnkd.in/grAvXyBF

This survey article aims at #covering #deep #internal #learning #techniques that have been proposed in the past few years for these two important directions. While their main focus is on #image #processing #problems, most of the approaches that they survey are derived for #general #signals (vectors with recurring patterns that can be distinguished from noise) and are therefore applicable to other modalities.----Tom Tirer, Raja Giryes, Se Young Chun, Yonina Eldar More details can be found at this link: https://lnkd.in/g_yQ2-By

The article presents a #unifying #framework that covers several cases of interest, such as #single-#agent #Bayesian #learning, #multiagent #non-#Bayesian #learning, #adaptive #social #learning, #social #machine #learning, #partial #information #sharing, influence discovery, and many others. The presentation highlights important limitations of the traditional social learning strategies. One limitation is the #inability #to #track #well #drifting #conditions. Traditional approaches lead to stubborn agents, which resist new states of information and are slow to react to changes in the environment, like an opinion that changes over time. Another limitation of the traditional strategies is that they assume #perfect #knowledge of the data models, which is #seldom #available in #practice. The article illustrates recent advances that address these issues. They show how to #endow #multiagent #networks with adaptation abilities and how to build social machine learning solutions that learn the necessary models directly from the data. These are fundamental steps toward the construction of socially intelligent networks, capable of exploiting cooperation and diversity across the agents to guarantee reliable learning performance under nonstationary, heterogeneous, and uncertain environments.----Virginia Bordignon, @Vincenzo Matta, @Ali Sayed More details can be found at this link: https://lnkd.in/gJqK3YTr

This paper show how to #design a #cheap #system for #detecting when #music is #present in #audio #recordings. They make use of a small #neural #network consisting of a simple #multilayer #perceptron (#MLP) along with compact features derived from the mel spectrogram by means of temporal integration.----Zafar Rafii, Erling Wold, Richard Boulderstone More details can be found at this link: https://lnkd.in/gniGsEDS

In this paper, they address these issues by performing a systematic review to identify the #key #trends of how #explainable #AI is used in #remote #sensing and shed light on novel explainable AI approaches and emerging directions that tackle specific remote #sensing #challenges. They also reveal the #common #patterns of explanation interpretation, discuss the #extracted #scientific insights in remote sensing, and reflect on the approaches used for explainable AI methods evaluation. As such, their review provides a complete summary of the #state-#of-#the-#art of explainable AI in remote sensing. Further, they give a #detailed #outlook on the challenges and promising research directions, representing a basis for novel methodological development and a useful starting point for new researchers in the field.----Adrian H., Ivica Obadic, @Miguel-ángel Fernández-Torres, , Hiba Najjar, @Dario Augusto Borges Oliveira, Zeynep Akata, Andreas Dengel, @Xiao Xiang Zhu More details can be found at this link: https://lnkd.in/gT7qtpS5