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    DFT-based multi-directions directional modulation
    (Institute of Electrical and Electronics Engineers, 2019) Hafez, Mohammed; Khattab, Tamer; Arslan, Hüseyin
    In this letter, a physically secure multi-directions directional modulation scheme is proposed. The scheme provides an adaptive beam-width assignment, where each user is granted a different beam width based on its channel condition. The scheme can be efficiently implemented using a discrete Fourier transform (DFT)-based algorithm that divides the spatial dimension into orthogonal narrow sub-beams. Each user is assigned multiple sub-beams that satisfies its pre-set direction of transmission and beam-width requirements. The scheme preserves the secrecy properties of directional modulation algorithms, where each legitimate user is guaranteed a secure communication link to its trusted receiver. The proposed scheme is practically efficient since it can be directly implemented using a DFT-based signal processing core.
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    Satellite
    (2023) Kota, Sastri; Giambene, Giovanni; Abdelsadek, Mohammed; Alouini, Mohamed Slim; Amay, Marc; Babu, Sarath; Bas, Joan; Cassara, Pietro; Chaudhari, Sachin; Dalai, Debabrata; Darwish, Tasneem; De Cola, Tomaso; Delamotte, Thomas; Dutta, Ashutosh; Dwivedi, Ayush; Enright, Michael; Giordani, Marco; Gotta, Alberto; Hammad, Eman; Khattab, Tamer; Knopp, Andreas; Karabulut Kurt, Güneş; Madoery, Pablo G.; Manoj B.S.; Me Biomo, Jean Daniel Medjo; Pillai, Prashant; Rawat, Pramud; Saxena, Paresh; Scanlan, Pat; Sharma, Avinash; Solaija, Muhammad Sohaib Jamal; Sperber, Ray; Sun, Zhili; Tarchi, Daniele; Varshney, Neeraj; Verma, Seema; Watts, Simon; Yanıkömeroğlu, Halim; Zhao, Kanglian; Zhao, Liang
    The fifth generation (5G) wireless communication systems development has brought about a paradigm shift using advanced technologies; including softwarization, virtualization, massive MIMO, and ultradensification, in addition to introducing new frequency bands. However, as societal needs for any form of information grow, it is necessary to satisfy the UN's Sustainable Development Goals (SDGs). Migrations to 6G and beyond systems are envisioned to provide augmented capacity, so massive IoT, with better performance relying on optimization made possible by artificial intelligence, it is absolutely necessary. Non-Terrestrial Networks (NTNs), including satellite systems, High-Altitude Platforms (HAPs), and Unmanned Aerial Vehicles (UAVs), provide the best solutions to connect the unconnected, unserved, and underserved in remote and rural areas. Over the past few decades, Geo Synchronous Orbits (GSO) satellite systems have been deployed to support broadband services, backhauling, Disaster Recovery and Continuity of Operations (DR-COOP), and emergency services. Recently, novel non-GSO satellite systems are attracting significant interest. Within the next few years, several thousands of Low Earth Orbit (LEO) satellites and mega-LEO constellations will provide global internet services, offering user throughput comparable to terrestrial mobile or fixed access networks. This report represents the 2023 Edition of the INGR Satellite Working Group Report, following the previous three editions [1]-[3]. This edition of the INGR Satellite Working Group Report addresses NTN and 6G more in detail, adding further contributions on optical wireless communications, artificial intelligence techniques, seamless handover, security, and recent standardization efforts given the prospected unification of terrestrial and NTN components of 6G.
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    Secure multiple-users transmission using multi-path directional modulation
    (Institute of Engineers and Everyone Else, 2016) Hafez, Mohammed; Khattab, Tamer; Elfouly, Tarek; Arslan, Hüseyin
    This work introduces a physical-layer secure multiple-users communication scheme. Our scheme employs the multi-path nature of the wireless channel to provide a different secure communication link for each of the legitimate users. We show that the proposed scheme highly degrades the eavesdroppers channel even for the worst case scenarios. We also provide the secrecy capacity and secrecy outage probability for the proposed scheme. We analyze the effect of the number of users, channel paths, and antenna elements on the secrecy performance of the scheme.
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    Secure spatial multiple access using directional modulation
    (IEEE-Institute of Electrical and Electronics Engineers Inc, 2018) Hafez, Mohammed; Yusuf, Marwan; Khattab, Tamer; Elfouly, Tarek; Arslan, Hüseyin
    In this paper, we introduce a secure multiple access scheme, which exploits the multipath structure of the channel to create a multi-user interference environment. The generated interference enables legitimate users to share time and frequency resources over spatially secure communication links. Utilizing directional modulation, we ensure secrecy for legitimate users against eavesdropping while preserving mutual confidentiality between the legitimate users themselves. Moreover, we introduce a complementary scheme for covering the non-selective channel case. The scheme uses directional modulation in coordinated multi-point transmission to provide location-specific secure communication to legitimate users. We characterize the achievable performance using a newly defined metric called vulnerable region. We provide analysis for the achievable secrecy rate, secrecy outage probability, and channel correlation effect on the secrecy performance for the proposed scheme. Furthermore, the effect of the channel spatial diversity, channel estimation error, and the number of legitimate users on the secrecy performance is studied.
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    Smart and secure wireless communications via reflecting intelligent surfaces: A short survey
    (IEEE-Institute of Electrical and Electronics Engineers Inc, 2020) Almohamad, Abdullateef; M. Tahir, Anas; Al-Kababji, Ayman; Madni, Haji Muhammad Furqan Ahmed; Khattab, Tamer; Hasna, Mazen Omar; Arslan, Hüseyin
    With the emergence of the Internet of Things (IoT) technology, wireless connectivity should be more ubiquitous than ever. In fact, the availability of wireless connection everywhere comes with security threats that, unfortunately, cannot be handled by conventional cryptographic solutions alone, especially in heterogeneous and decentralized future wireless networks. In general, physical layer security (PLS) helps in bridging this gap by taking advantage of the fading propagation channel. Moreover, the adoption of reconfigurable intelligent surfaces (RIS) in wireless networks makes the PLS techniques more efficient by involving the channel into the design loop. In this article, we conduct a comprehensive literature review on the RIS-assisted PLS for future wireless communications. We start by introducing the basic concepts of RISs and their different applications in wireless communication networks and the most common PLS performance metrics. Then, we focus on the review and classification of RIS-assisted PLS applications, exhibiting multiple scenarios, system models, objectives, and methodologies. In fact, most of the works in this field formulate an optimization problem to maximize the secrecy rate (SR) or secrecy capacity (SC) at a legitimate user by jointly optimizing the beamformer at the transmitter and the RIS's coefficients, while the differences are in the adopted methodology to optimally/sub-optimally approach the solution. We finalize this survey by presenting some insightful recommendations and suggesting open problems for future research extensions.
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    Thresholds optimization for one-bit feedback multi-user scheduling
    (Institute of Electrical and Electronics Engineers Inc., 2018) Hafez, Mohammed; El Shafie, Ahmed; Shaqfeh, Mohammed; Khattab, Tamer; Alnuweiri, Hussein; Arslan, Hüseyin
    We propose a new one-bit feedback scheme with scheduling decision based on the maximum expected weighted rate. We show the concavity of the 2-user case and provide the optimal solution which achieves the maximum weighted rate of the users. For the general asymmetric M-user case, we provide a heuristic method to achieve the maximum expected weighted rate. We show that the sum rate of our proposed scheme is very close to the sum rate of the full channel state information case, which is the upper bound performance.