Electrical and Electronic Engineering - Research Publications

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    Reconfigurable optical crosshaul architecture for 6G radio access networks
    Tao, Y ; Ranaweera, C ; Edirisinghe, S ; Lim, C ; Nirmalathas, A ; Wosinska, L ; Song, T (Optica Publishing Group, 2023-12)
    The radio access network (RAN) architecture is undergoing a significant evolution to support the next-generation mobile networks and their emerging applications. To realize scalable and sustainable deployment and operations, RAN needs to consider the requirements of 6G and beyond wireless technologies such as ultra densification of cells, higher data rates, ubiquitous coverage, and new radio spectrum in the millimeter-wave band. This calls for a careful redesign of every aspect of RAN, including its crosshaul. The crosshaul is an important network segment in future RAN, capable of transporting diverse traffic types with varying stringent requirements within RAN. The crosshaul towards 6G is envisioned to be highly intelligent, reconfigurable, and adaptable to dynamic service requirements and network conditions. To this end, we propose a software defined network (SDN)-enabled reconfigurable optical crosshaul architecture (ROCA) that supports heterogeneous crosshaul transport technologies and dynamic functional splittings. ROCA enables efficient and intelligent control of the crosshaul data plane. The proposed architecture with a set of the next-generation RAN (NG-RAN) transport interfaces is evaluated using network models built on the ns-3 network simulator. Simulation results demonstrate the strengths and weaknesses of different crosshaul interfaces in agreement with the understanding of respective NG-RAN interfaces from the literature, which validates the modeling accuracy. We then demonstrate the reconfigurability of the architecture using a dynamic scenario with different reconfiguration strategies for meeting the user and network demands. The results indicate that ROCA serves as a scalable and flexible foundation for supporting high-capacity delay-stringent RAN that can be used in 6G and beyond wireless technologies.
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    A Geometry-Based Distributed Connectivity Maintenance Algorithm for Discrete-time Multi-Agent Systems with Visual Sensing Constraints
    Li, X ; Fu, J ; Liu, M ; Xu, Y ; Tan, Y ; Xin, Y ; Pu, Y ; Oetomo, D (WORLD SCIENTIFIC PUBL CO PTE LTD, 2024-03-01)
    This paper presents a novel approach to address the challenge of maintaining connectivity within a multi-agent system (MAS) when utilizing directional visual sensors. These sensors have become essential tools for enhancing communication and connectivity in MAS, but their geometric constraints pose unique challenges when designing controllers. Our approach, grounded in geometric principles, leverages a mathematical model of directional visual sensors and employs a gradient-descent optimization method to determine the position and orientation constraints for each sensor based on its geometric configuration. This methodology ensures network connectivity, provided that initial geometric constraints are met. Experimental results validate the efficacy of our approach, highlighting its practical applicability for a range of tasks within MAS.
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    Wearable Transmitter Coil Design for Inductive Wireless Power Transfer to Implantable Devices.
    Tai, Y-D ; Widdicombe, B ; Unnithan, RR ; Grayden, DB ; John, SE (IEEE, 2023-07)
    Wireless endovascular sensors and stimulators are emerging biomedical technologies for applications such as endovascular pressure monitoring, hyperthermia, and neural stimulations. Recently, coil-shaped stents have been proposed for inductive power transfer to endovascular devices using the stent as a receiver. However, less work has been done on the external transmitter components, so the maximum power transferable remains unknown. In this work, we design and evaluate a wearable transmitter coil that allows 50 mW power transfer in simulation.Clinical Relevance-This allows more accurate measurements and precise control of endovascular devices.
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    Event-Triggered Boundary Control of 2 x 2 Semilinear Hyperbolic Systems
    Strecker, T ; Cantoni, M ; Aamo, OM (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2024-01)
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    On Distributed Nonconvex Optimisation via Modified ADMM
    Mafakheri, B ; Manton, JH ; Shames, I (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2023)
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    Monolithic Integration of Single Quantum Emitters in hBN Bullseye Cavities
    Spencer, L ; Horder, J ; Kim, S ; Toth, M ; Aharonovich, I (AMER CHEMICAL SOC, 2023-11-17)
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    Decentralized event-triggered estimation of nonlinear systems
    Petri, E ; Postoyan, R ; Astolfi, D ; Nešić, D ; Heemels, WPMH (Elsevier BV, 2024-02-01)
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    Least-square Fitting on the Circle using Optimal Control
    Liu, C ; Suvorova, S ; Evans, RJ ; Moran, W ; Melatos, A (Elsevier BV, 2023-07-01)
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    Frequency Permutation Subsets for Joint Radar and Communication
    Dayarathna, S ; Senanayake, R ; Smith, P ; Evans, J (Institute of Electrical and Electronics Engineers (IEEE), 2024-02-01)
    This paper focuses on waveform design for joint radar and communication systems and presents a new subset selection process to improve the communication error rate performance and global accuracy of radar sensing of the permutation based random stepped frequency radar waveform. An optimal communication receiver based on integer programming is proposed to handle any subset of permutations followed by a more efficient sub-optimal receiver based on the Hungarian algorithm. Considering optimal maximum likelihood detection, the block error rate is analyzed under both additive white Gaussian noise and correlated Rician fading. We propose two methods to select a permutation subset with an improved block error rate and an efficient encoding scheme to map the information symbols to selected permutations under these subsets. From the radar perspective, the ambiguity function is analyzed with regards to the local and the global accuracy of target detection. Furthermore, a subset selection method to reduce peak-to-sidelobe ratio (PSLR) is proposed by extending the properties of Costas arrays. Finally, the process of remapping the frequency tones to the symbol set used to generate permutations is introduced as a method to improve both the communication and radar performances of the selected permutation subset.
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    Bit Modulated Frequency Permutation Waveforms for Joint Communications and Radar
    Dayarathna, S ; Senanayake, R ; Evans, J ; Smith, P (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2023-12)
    In this paper, we propose the selection of a subset of waveforms based on the random stepped frequency permutation waveform to support joint radar and communication. More specifically, we solve two critical implementation problems arising from the subset selection which is motivated by the fundamental bit level operation requirements of communication systems. Noting that the practicality of any selected subset depends on the feasibility of efficient implementation, we focus on finding a specific subset for which we can design an efficient mapping process and a receiver implementation. More specifically, we propose an efficient process to map information bits to waveforms based on the factorial number system. An efficient optimal communication receiver that utilizes the Hungarian algorithm is also designed. For additive white Gaussian noise and correlated Rician fading channels, the bit error rate is analyzed in accordance with the optimum maximum likelihood detection.