Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 58 for “"Channel state information (CSI)"”.
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A Study of Wireless Modem Performance Using Multiple Element Antennas
… the demand for high data rate. In correlated channels Channel State Information (CSI) at the transmitter provides a significant capacity increase over conventional Multiple Input Multiple Output (MIMO) systems. In such a case, the Singular Value Decomposition (SVD) of the channel matrix gives …
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Space-time block coding with imperfect channel estimates
… receiver. The performance of STBC with perfect channel state information (CSI) being available at the receiver has been shown to provide approximately 10 dB of improvement over uncoded transmission in Rayleigh fading when using Quadrature Phase Shift Keying (QPSK) at a bit error rate of 10 -3. …
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New hybrid automatic repeat request (HARQ) scheme for 4x4 MIMO system, based on the extended alamouti quasi-orthogonal space-time bloc coding (Q-STBC), in invariant and variant fading channel
… (MIMO) system in invariant and variant fading channel conditions is proposed and analized. Based on the Extended Alamouti Quasi-orthogonal Space-Time Block Coding (Q-STBC), the use of the so-called Alternative Matrices for transmission, depending on the Channel State Information (CSI) received …
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Towards location-awareness in next generation wireless networks : a new approach based on channel state information
… a novel approach to localization based on soft information (SI), exploiting all positional information inherent in measurement and contextual data, has been proposed. This thesis further develops SI-based localization by establishing a new approach relying on channel state information (CSI) …
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Multiantenna Communications in the Presence of Feedback
… of communication schemes for wireless systems. Channel state information (CSI) at the transmitter end is often an essential requirement when one wishes to fully utilize the potential gain promised by multiantenna technology. This requirement has sparked enormous interest in the design of …
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Advanced wireless communications using large numbers of transmit antennas and receive nodes
… be used for training signal transmissions and channel state information (CSI) feedback. First, we propose practical open-loop and closed-loop training frameworks to reduce the overhead of the downlink training phase. We then discuss efficient CSI quantization techniques using a trellis search. …
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Linear Precoding for Downlink Network MIMO Systems
… user throughput. First, we assume there is full channel state information (CSI) available at the transmitter side, and using the concept of signal-to-leakage ratio (SLR), we develop a linear precoding scheme to increase the spectral efficiency. In the second part, we assume partial CSI at the …
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Communications over fading channels with partial channel information : performance and design criteria
… under the assumption that some statistical information of the wireless fading channels is available. These results are useful in determining the optimal design of system parameters. Suboptimal receivers are designed for systems that are constrained in terms of implementation complexity. The …
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Propagation models for multiple-antenna systems : methodology, measurements and statistics
… largely dependent on the accuracy of available channel models for approximating realized propagation behavior. The first contribution of this thesis is a methodology for the modeling of wireless propagation in multiple antenna systems. Specifically we consider the problem of propagation modeling …
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Improving the Performance of Wireless Systems via Selective Interference Nulling and Adaptive Medium Access Control Design
… the mobile handset to suppress a few dominant cochannel interferers (CCI) out of a total of L active independent but non-identically distributed Rayleigh faded CCI signals. Earlier works on this subject chose an unrealistic i.i.d assumption for the cochannel interferers. Since the CCI signals are …
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Link adaption with limited feedback for future wireless networks
… in the downlink transmission and converted to channel state information (CSI), which is sent via feedback channel in the uplink direction to the base station. The amount of feedback required for adaptive MCS and scheduling at the BS increases with the number of users which consumes significant …
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Structure-based learning via graph neural networks for multi-group multicast beamforming
… solution, they are designed under perfect channel state information (CSI) and need to be performed each time channel state information is updated. Due to the complexity involved in solving the problem, they lead to high computational run-time for largescale antenna-array systems. To …
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Channel estimation and signal enhancement for DS-CDMA systems
… space-time (S-T) transceiver design, and S-T channel parameter estimation for direct-sequence code-division multiple-access (DS-CDMA) systems. Using the Bayesian framework, various linear and simplified nonlinear multiuser detectors are proposed, and their performances are analyzed. The …
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Machine learning applications in plant identification, wireless channel estimation, and gain estimation for multi-user software-defined radio
… of: plant identification from images of leaves, channel state information (CSI) estimation for wireless multiple-input-multiple-output (MIMO) systems, and gain estimation for a multi-user software-defined radio (SDR) application. </p><p>In the first task, two methods for plant species …
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Channel estimation for Gigabit Multi-user MIMO-OFDM Systems
The fundamental detection problem in fading channels involves the correct estimation of transmitted symbols at the receiver in the presence of Additive White Gaussian Noise (AWGN). Detection can be considered when the receiver is assumed not to know the channel (non-coherent detection), or …
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Spectral efficiency optimization with channel state information of a massive MIMO System
… been proposed for a system that has imperfect channel state information. Many wireless communication operations can be formulated as nonconvex non-smooth optimization problems. Often there is lack of effective algorithms for these problems especially in the event that the optimization variables …
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MSE-based Linear Transceiver Designs for Multiuser MIMO Wireless Communications
… consider the design of transceivers assuming channel state information (CSI) at the transmitter. We consider minimization of the sum-MSE over all users subject to a sum power constraint on each transmission. Using MSE duality, we solve a computationally simpler convex problem in a virtual …
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Relay Selection Strategies for Multi-hop Cooperative Networks
… decoding set with the largest number of ``good'' channels to the next stage is selected for retransmission. We analyze the performance of this method in terms of end-to-end outage probability in the case of perfect and imperfect channel state information (CSI). We also investigate relay selection …
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Channel modeling and resource allocation in OFDM systems
… to broadband communication systems. The radio channel is plagued by multipath propagation, which causes frequency-selective fading in broadband signals. Orthogonal Frequency-Division Multiplexing (OFDM) is a modulation scheme specifically designed to facilitate high-speed data transmission over …
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Reconfigurability in Wireless Networks: Applications of Machine Learning for User Localization and Intelligent Environment
… DL in wireless network reconfigurability and channel modeling is studied and summarized. While deep learning based methods have been applied in a few wireless network use cases, there is still much to be explored in many wireless channel modeling scenarios such as predicting channel state …
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