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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Design of Multi-Beam Hybrid Digital Beamforming Receivers

Madishetty, Suresh January 2018 (has links)
No description available.
12

Hybrid Beamforming Design for Full-Duplex mmWave Relaying Systems

Wu, Zhe January 2020 (has links)
With the tremendous growth in the mobile data traffic, the demand for highdata rate is increasing rapidly, and higher frequency resources shall be exploredto alleviate the congestion in the overcrowded spectrum, thus, the millimeterwave (mmWave) frequency resource ranging from 30 GHz to 300 GHz has beenrecognized as a nature fit for the fifth-generation (5G) and beyond network. Tocompensate the severe path-loss in the mmWave band as well to realize theefficient transmissions by applying the low-cost architecture, it is of intereststo investigate the beamforming schemes with large-scale antenna arrays andthe full-duplex (FD) relaying strategy, which are indispensable in the operationof directional signal transmission and the efficient spectrum utilization inthe mmWave transmission, respectively. However, the self-interference (SI)occurring between the separate antenna arrays is the main impediment inrealizing a FD wireless node while considering the simultaneous transmission andreception.This thesis project aims to design efficient hybrid beamforming algorithms toimprove spectral efficiency and eliminate SI. The orthogonal matching pursuit(OMP)-based hybrid analog-digital beamforming design, and the alternatingdirection method of multipliers (ADMM)-based schemes are explored to improvethe spectral efficiency and eliminate the SI in this work. Moreover, a fast ADMMenabledhybrid precoding approach with SI cancellation is proposed to achievethe efficient performance and superior convergence compared with the existingschemes, as it is verified by the presented numerical simulations. / Med den enorma tillväxten i den mobila datatrafiken ökar efterfrågan påhög datahastighet snabbt, och högre frekvensresurser ska undersökas för attminska trängseln i det överbefolkade spektrumet, vilket innebär att Volymvågens(mmwave) frekvensresurs, som sträcker sig från 30 GHz till 300 GHz, har erkäntssom en naturlig resurs för den femte generationen (5G) och utanför nätverket.För att kompensera den allvarliga förlusten av tågläge i mmwave-bandet ochför att förverkliga de effektiva sändningarna genom att tillämpa den billigaarkitekturen.Det är av intresse att undersöka strålformningsprogrammen medstorskaliga antennmatriser och strategin för återutläggning av hela duplex (FD),som är oumbärliga för att driva den direkta signal överföringen och det effektivaspektrumutnyttjandet i mmwave-transmissionen.separata antennmatriser är etthuvudhinder för att förverkliga en trådlös nod från FD samtidigt som manöverväger samtidig överföring och mottagning.Syftet med detta avhandlingsprojekt är att utforma effektiva kombineradestrålformningsinformationsalgoritmer för att förbättra spektraleffektiviteten ocheliminera SI. Den ortogonala matchande jakten (OMP)-baserad hybrid analogdigitalstrålformning, och metoden med alternerande riktning för multiplikatorer(ADMM)-baserade system utforskas för att förbättra spektraleffektiviteten ochelimineraSI i det här arbetet. Dessutom föreslås en snabb, adMM-aktiveradhybrid förkonditionering med SI-annullering för att uppnå effektiv prestandaoch överlägset konvergens jämfört med de befintliga systemen, eftersom denkontrolleras av de presenterade numeriska simuleringarna.
13

Adaptive and Robust Multi-Gigabit Techniques Based MmWave Massive MU-MIMO Beamforming For 5G Wireless and Mobile Communications Systems. A Road Map for Simple and Robust Beamforming Scheme and Algorithms Based Wideband MmWave Massive MU-MIMO for 5G Wireless and Mobile Communications Systems

Alabdullah, Ali AbdulMohsin S. January 2021 (has links)
Over recent years, the research and studies have focused on innovative solutions in various aspects and phases related to the high demands on data rate and energy for fifth-generation and beyond (B5G). This thesis aims to improve the energy efficiency, error rates, low-resolution ADCs/DACs, antenna array structures and sum-rate performances of a single cell downlink broadband millimetre-wave (mmWave) systems with orthogonal frequency division multiplexing (OFDM) modulation and deploying multi-user massive multiple inputs multiple outputs (MU mMIMO) by applying robust beamforming techniques and detection algorithms that support multiple streams per user (UE) in various environments and scenarios to achieve low complexity system design with reliable performance and significant improvement in users perceived quality of service (QoS). The performance of the four 5G candidate mmWave frequencies, 28 GHz, 39 GHz, 60 GHz, and 73 GHz, are investigated for indoor/outdoor propagation scenarios, including path loss models and multipath delay spread values. Results are compared to confirm that the received power and delay spread is decreased with increasing frequency. The results were also validated with the measurement findings for 60 GHz. Then several proposed design models of beamforming are studied and implemented modified algorithms of Hybrid Beamforming (HBF) approaches in indoor/outdoor scenarios over large scale fading wideband mmWave /Raleigh channels. Firstly, three beamforming based diagonalize the Equivalent Virtual Channel Matrix (EVCM) schemes with the optimal linear combining methods are presented to overcoming the self-interference problems in Quasi-Orthogonal-Space Time Block Code (QO-STBC) systems over narrowband mmWave Single-User mMIMO (SU mMIMO). The evaluated results show that the proposed beamforming based- Single Value Decomposition (SVD) outperforms the conventional beamforming and standard QO-STBC techniques in terms of BER and spectrum efficiency. Next, the proposed HBF algorithm approaches with the fully/ partially connected structures are developed and applied for sum-rate and symbol error rate (SER) performance maximization MU mMIMO-OFDM system, including HBF based on block diagonalization (BD) method Constraint/Unconstraint RF Power, Codebook, Kalman schemes. In addition, the modified near optimal linear HBF-Zero Forcing (HBF-ZF) and HBF-Minimum Mean Square Error (HBF MMSE) schemes, considering both fully-connected and partially-connected structures. Finally, Simulation results using MATLAB platform, demonstrate that the proposed HBF based codebook and most likely HBF based-unconstraint RF power algorithms achieve significant performance gains in terms SER and sum-rate efficiency as well as show high immunity against the deformities and disturbances in the system compared with other HBF algorithm schemes. / Ministry of Higher Education and Scientific Research, the Republic of Iraq

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