Shannon Wireless’ Post

This paper focuses on providing a #theoretical #framework for the #evaluation of the #performance of #holographic #reconfigurable #intelligent #surface (#HRIS) empowered #terahertz (#THz) wireless systems under fog conditions. In more detail, the authors present a comprehensive methodology for evaluating the geometric losses of the #end-#to-#end #channel. Moreover, the stochastic nature of the end-to-end channel is characterized by novel closed-form probability density and cumulative distribution functions. Building upon them, the outage probability and the throughput of the system are extracted in closed form.----Alexandros-Apostolos A. Boulogeorgos, Stylianos E. Trevlakis, Theodoros Tsiftsis More details can be found at this link: https://lnkd.in/gMiZ9T_G

This paper proposes a #metapath-#based #heterogeneous #graph-#transformer #network (#MHGphormer) to bypass the #channel #estimation #phase. The authors formulate a #sum-#rate #maximization #problem with #quality-#of-#service (#QoS) constraints in a #reconfigurable #intelligent #surface (#RIS)-aided #multiuser #multiple-#input #multiple-#output (#MU-#MIMO) #Terahertz (#THz) system to optimize the precoding, phase shifts, and #adaptive #sub-#band #bandwidth (#ASB) allocation. ----Ali Mehrabian, @Vincent W. S. Wong More details can be found at this link: https://lnkd.in/ggxb9hsS

This paper analyzes the feasibility of device identification exploiting the unique non-linear memory effect of the transmitter #radio #frequency (#RF) chains consisting of matched pulse shaping filters and non-linear #power #amplifiers (#PAs). This unique feature can be extracted from the received distorted #constellation #diagrams (#CDs) with the help of image recognition-based classification algorithms. In order to validate the performance of the proposed #radio #frequency #fingerprint (#RFF) approach, experiments are carried out in cabled and #over #the #air (#OTA) scenarios. ---- YUEPEI LI, Yuan Ding, Junqing Zhang, Goussetis George, Symon K. Podilchak More details can be found at this link: https://lnkd.in/ef5Zjtiq

This letter proposes an algorithm that maximizes the signal-to-noise ratio at the user by optimizing the number of active loads, the complex-valued reflection coefficients at the #Reconfigurable #Intelligence #Surface (#RIS) array, and the transmit power at the access point. Towards a fairness-oriented design, the authors compare the performance provided by passive RIS, active RIS, and hybrid RIS. ----Davi V. Q. Rodrigues More details can be found at this link: https://lnkd.in/g4FTtdu7

This letter proposes a framework for #parameter #estimation and #data #detection in the uplink of #IRS-#assisted #MIMO systems in the presence of #channel #aging. First, the authors model the received pilot signal as a #tensor to estimate the channel parameters and to design the IRS phase shifts. Then, their proposed tensor approach tracks the aging process to jointly estimate the aged components and the transmitted data. Compared to state-of-the-art schemes, the numerical results show that their proposed solution improves the performance of IRS-assisted MIMO systems in terms of normalized mean squared error and bit error ratio. ---- Kenneth B. A. Benício, André L. F. de Almeida, Bruno Sokal, Fazal-E- Asim, Behrooz Makki, Gabor Fodor More details can be found at this link: https://lnkd.in/exN2RJZB

In this paper, the authors present #LensFD, a scalable method to enable cost-effective massive MIMO #full-#duplex operation in sub-6 GHz frequencies with a focus on the CBRS band of 3.5 GHz. LensFD uses a low-cost lens array combined with #transmit #precoding to reshape the effective beam pattern of antennas in massive MIMO arrays to reduce self-interference. The authors tested three lens configurations in LensFD experimentally with a software-defined 40-antenna base-station and demonstrate a significant improvement in self-interference reduction and hence overall increased system capacity to 1.6× over the #time-#division #duplex (#TDD) counterpart. As an important contribution, they will open-source the large measurement dataset from their experiments. ---- Zhican(West) Chen, C. Nicolas Barati Nt, Jon Veihl, Clayton Shepard, Ashutosh Sabharwal More details can be found at this link: https://lnkd.in/eznE5MgW

This paper investigates #reconfigurable #intelligent #surface (#RIS)-aided #frequency #division #duplexing (#FDD) communication systems. Since the downlink and uplink signals are simultaneously transmitted in FDD, the phase shifts at the RIS should be designed to support both transmissions. Considering a #single-#user #multiple-#input #multiple-#output #system, the authors formulate a #weighted #sum-#rate #maximization problem to jointly maximize the downlink and uplink system performance. To tackle the #non-#convex #optimization problem, they adopt an #alternating #optimization (#AO) algorithm, in which two phase shift optimization techniques are developed to handle the #unit-#modulus constraints induced by the reflection coefficients at the RIS.----Gyoseung Lee, Hyeongtaek Lee, @Donghwan Kim, Jaehoon Chung, @A. Lee Swindlehurst, Junil Choi More details can be found at this link: https://lnkd.in/g8bBCR6E

This paper proposes a #reconfigurable #intelligent #surface (#RIS)-assisted #rate-#splitting #multiple #access (#RSMA) system for overloaded MISO transmissions with imperfect channel state knowledge at the transmitter. In the proposed system, a weighted minimum mean square error (WMMSE)-based approach and alternative optimization framework are used to solve the weighted sum-rate optimization problem in RSMA transmissions with partial #channel #state #information. Both the phase-shifting matrix and beamforming matrix are iteratively optimized until convergence. The performance of time partitioning RSMA (TP-RSMA) and power partitioning RSMA (PP-RSMA) in terms of sum-rate is also examined. ---- Taissir Y. Elganimi More details can be found at this link: https://lnkd.in/gm3khMFb

This video series explains key concepts behind the 5G New Radio (NR) physical layer standard. Learn about the requirements and use cases through deep dive into the main features in each video.  #MATLAB #5G

In this paper, the authors consider a #stacked #intelligent #metasurface (#SIM) with the ability to perform #beamforming in the #electromagnetic (#EM) wave domain. They develop a path-loss model that allows them to compute the received power of the signal after passing through the SIM. Based on the proposed path-loss model, they formulate an optimization problem to maximize the power at a desired target location in space. They develop a #gradient #ascent #algorithm that can be applied when the phases of the meta-atoms of the SIM can be continuously varied. Also, they develop an #alternating #optimization (#AO) algorithm for the same problem when the meta-atoms can only apply discrete phase shifts. In addition, they formulate an optimization problem whose objective is to produce a given target radiation pattern on a 2D plane located at a certain distance from the center of the SIM. The corresponding algorithms for the continuous and discrete values for the transmission coefficients applied by the SIM are provided. ---- Naveed UL Hassan, Jiancheng An, Marco Di Renzo, Merouane Debbah, Chau Yuen More details can be found at this link: https://lnkd.in/gUmSJu7k