Shannon Wireless’ Post

Stacked Intelligent Surfaces (SIS) can be used in radio-frequency communication for beam focusing (as an "RF telescope"), as well as beam forming/steering, to optimize wireless communication. They enable wave-domain signal processing, allowing the migration of some transceiver tasks from the digital electric-domain to the analog wave-domain, with implications on energy efficiency and cost. Owing to these properties, in a recently accepted paper titled "Stacked-Intelligent-Surface-Assisted MIMO Integrated Sensing and Communication," we discuss the use of SIS for integrated sensing and communication. The paper will appear in the IEEE Networks Magazine. This paper was led by Omran Abbas and co-authored with Loïc Markley. In a future work, we will elaborate on the details of the case-study in this paper (integrated channel estimation and communication). Stay tuned!

This paper introduces a novel approach to maximize #low #Earth #orbit (#LEO) satellite coverage by leveraging #reconfigurable #intelligent #surface (#RIS) within 6G sub-#terahertz (#THz) networks. Optimization objectives include improving #end-#to-#end (#E2E) data rate, optimizing satellite-#remote #user #equipment (#RUE) associations, data packet routing within satellite constellations, RIS phase shift, and #ground #base #station (#GBS) transmit power (i.e., active beamforming). The formulated joint optimization problem poses significant challenges because of its time-varying environment, non-convex characteristics, and NP-hard complexity. To address these challenges, they propose a #block #coordinate #descent (#BCD) algorithm that integrates balanced K-means clustering, #multi-#agent #proximal #policy #optimization (#MAPPO) #deep #reinforcement #learning (#DRL), and #whale #optimization #algorithm (#WOA) techniques. ---- Sheikh Salman Hassan, Ph.D., Yu Min Park , Yan Kyaw Tun, Walid Saad , Zhu Han , Choong Seon Hong More details can be found at this link: https://lnkd.in/eQmHxryW

I would like to share with you a paper that has recently been published in IEEE Transactions on Wireless Communications. Conventional resource allocation methods focus on minimizing the summed gap between the provided capacity and the required traffic demand of beams. However, the coupling relationship among variables in the Shannon formula complicates this objective. In addition to frequency efficiency, energy consumption is a key priority for communication systems. In this paper, under the condition of full-band frequency reuse, we propose minimizing total transmission energy consumption, while ensuring perfect demand-matching performance (equality constraint). These equality constraints not only avoid increasing the complexity of the problem but also provide additional information that aids in solving it.

The current #worldwide #energy and #economical #crisis #triggers the need of more #sustainable #technological #solutions to #implement #energy-#efficient next generation communication systems, which should also be commercially viable and costeffective. Moreover, future terrestrial and satellite communications will bring a wide range of use cases, services and environments with very different requirements and specifications to fulfill in order to generate a #smart #digital #fully #connected #society. Designing new antennas for each single application is not feasible since it is very complex to meet the customer´s demand in the short run, and antenna system solutions that are easily #re-#configurable to be re-used in diverse scenarios are needed. The combination of lenses with traditional phased array antennas (also known as dome antennas) is a promising way of mixing the advantages of both antenna technologies and optimizing the performance of our systems depending on the use case scenario. This article discusses the #industrial and #technical #potential of using dome antennas implemented in different technologies for expected use cases and applications of future terrestrial and satellite communication systems.----Astrid Algaba Brazalez, Pilar Castillo Tapia, @Maria Carolina Vigano, Oscar Quevedo Teruel More details can be found at this link: https://lnkd.in/get6UGhr

Great news! Our paper "Wireless Communications with Space-Time Modulated Metasurfaces" has been finally published on IEEE Journal of Selected Areas in Communications, and released in early access on IEEE explore! Thanks to my co-authors Marouan Mizmizi and Umberto Spagnolini. The paper deals with the usage of time-modulated metasurfaces for high data-rate wireless communications, and it focuses on the coupling between the spatial phase gradient (used to steer the reflection) and the temporal one (used to convey information via modulation of the impinging signal). Proper countermeasures to coupling are thoroughly discussed. The paper is supported by the European Union under the Italian National Recovery and Resilience Plan (NRRP) of NextGenerationEU, within the Fondazione RESTART. Check the paper out at: https://lnkd.in/dnPF-QDR #metasurfaces #wireless #communications #6g #research #polimi

This paper addresses the challenge of #enhancing #energy #efficiency in #Visible #Light #Communication (#VLC) networks through #Space #Division #Multiplexing (#SDM) and smart lighting integration. They mathematically formulate the problem of #energy-#efficient #multi-#user #VLC #networking with SDM and smart illumination, tailoring the light output according to the users’ demands. To address the arising intricate optimization problem, they propose #Clustered #Light #Emitting #Diode (#LED) #Assignment and #Power #optimization (#CLAP). This heuristic approach leverages #density-#based #spatial #clustering for efficient user grouping and employs a greedy sequential algorithm for LED assignment. The constrained optimization by linear approximation technique is employed to determine transmitted optical power levels. ----Elahe Zolala, Mohammad Amir Dastgheib, @Hamzeh Beyranvand, @Jawad A. Salehi More details can be found at this link: https://lnkd.in/gkukAK3D

We believe that the concept of Space Time modulation with metasurfaces is a new milestone on the understanding of novel propagation processing that can be better investigated within the wireless community

In this paper, the authors focus on cooperative sensing where the transmitter and receivers are non-co-located, which includes the bistatic and multistatic sensing. Specifically, the system model of cooperative sensing based on mobile networks is established. To demonstrate the feasibility of cooperative sensing, the bistatic #radar #cross #section (#RCS) is provided. As for the sensing method, a #refined #orthogonal #matching #pursuit (#R-#OMP) method is proposed to estimate the channel parameters and data fusion is also provided to derive the objects’ positions and velocities. Considering the non-negligible interference in the cooperative #joint #sensing #and #communication (#JSAC) networks, they also discuss interference management in this paper. ---- Guangyi Liu, Rongyan Xi, Zixiang Han, Lincong Han, Xiaozhou Zhang, Liang Ma, Yajuan Wang, Mengting Lou, Jing Jin, Qixing Wang, Jiangzhou Wang More details can be found at this link: https://lnkd.in/gXfGq_9F

Throughout my PhD, I’ve been focusing on smart antennas for LEO satellite applications, studying phased array antennas, digital beamforming and mmWaves propagation. As it is known, directional communication and MIMO antennas are seen as an opportunity to overcome modern telecommunication systems issues. As such, I’ve dived into the analysis of how high levels of mutual coupling impact an antenna’s performance and how this problem can be mitigated. The result is a literature review, published in IEEE Access, entitled “A Review on Mutual Coupling Reduction Techniques in mmWaves Structures and Massive MIMO Arrays” that compares the achievements obtained with the respective approaches, showcasing the advantages and downsides of each technique studied. This work strongly contributes to making antenna arrays more energy and spectrum efficient. #antennaarrays #radiofrequency #antennadesign #mutualcoupling #MIMO

This paper investigates the role of #reconfigurable #intelligent #surface (#RIS) for enhanced handover management in 6G networks with overlapping wireless network layers i.e ., ground, aerial, and space. A #high #altitude #platform #system (#HAPS) is equipped with RIS and the comparison of direct and #RIS-assisted link performance is presented. To do this, the average bit error rate, the #outage #probability (#OP), and the channel capacity of direct and HAPS-assisted links are obtained in closed form expressions. By estimating the link error probability, a novel handover mechanism exploits the use of RIS, resulting in enhanced connectivity management. Hard and soft handover modes are defined depending on the #radio #frequency (#RF) connectivity by means of link error threshold. The decision for the handover execution is based on selecting the optimal link among multiple available ones from ground, aerial, and space layers. The performance of RIS-assisted handover mechanism has been compared to traditional hard and soft handover procedure, as well as link performance achieved with relay node. Numerical and simulation results reveal that the connectivity of a user equipment can be maintained through RIS-aided links in case of any performance degradation in the direct RF links. Particular scenarios highlight that the use of RIS for handover is preferred to traditional handover procedures, as well as relay nodes. ----Anna Maria Vegni @Yalçın Ata; @Mohamed Slim Alouini More details can be found at this link: https://lnkd.in/gRqvdPQt