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 17 of 17 for “"Frequency synchronization"”.
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Timing and frequency synchronization in OFDM broadband wireless systems
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.
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On the performance and capacity of space-time block coded multicarrier CDMA communication systems
… STBC MC-CDMA systems in the presence of carrier frequency offset (CFO). Then various multirate access schemes, multicode, variable spreading gain (VSG) and multiple symbol rate (MSR), are investigated. Next, the thesis looks into some of design and implementation issues of STBC MC-CDMA systems. …
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Optimización algorítmica orientada a la implementación en dispositivos reconfigurables de esquemas multiestándar y multiusuario para sincronismo de frecuencia en sistemas de comunicaciones inalámbricas basados en OFDM
… empleada. ABSTRACT This Thesis focuses on the frequency synchronization problem in OFDM, multistandard OFDM and OFDMA systems. The aim of this Thesis is to propose new synchronization schemes with a reduced computation complexity compared with previous methods from the literature in order to …
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Energy-Efficient Collaborative Communications for Wireless Sensor Networks
… collaborative communication systems i.e., phase, frequency and time synchronization errors, are identified. A synchronization process is designed to reduce the phase and frequency synchronization errors among the collaborative nodes and the base station. The theoretical model of the collaborative …
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Six-port wireless receiver architectures
… which relate to dual-tone calibration. receiver frequency synchronization and dual-tone linearization of onboard diode detector are also proposed.<br/><br/>A modelling strategy for each of the lumped elements required to construct a six-port digital receiver using RFCMOS technology has been …
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Highly parallelized control programming methodologies using multicore CPU and FPGA for highly dynamic multi-DoF mobile robots, applied to the MIT Cheetah
… it is critical for the robot to achieve a high-frequency synchronization of data processing from a large number of high-bandwidth actuators and sensors. To solve this important problem in robotics, I developed parallelized control programming methodologies that effectively utilize the advantages …
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Enhancing spectrum utilization through cooperation and cognition in wireless systems
… physical layer and allocating to each link the frequency bands that show the highest performance for that link. SourceSync, the third system, enables wireless nodes in last-hop and wireless mesh networks to cooperatively transmit synchronously in order to exploit channel diversity and increase …
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The Impact of Electrical Standards on MVDC Shipboard Power Cable Size
… and avoidance of alternating current (AC) frequency synchronization issues when combining outputs from multiple sources [1]. However, few MVDC systems are currently in operation, and little is known in terms of design and test parameters in comparison to the vast wealth of knowledge …
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Spectrum Sensing in the Presence of Channel and Tx/Rx Impairments
… which relaxes the requirements of perfect frequency synchronization and knowledge of the phase information of the received signal that the likelihood-based approach requires. Finally, research is presented on the impact that both sensor reliability and sensor correlation information have on …
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Self-synchronized converter for fast synchronization between low voltage microgrid and inverter connection
In this research, a fast-synchronization between single-phase microgrid and inverter in low voltage, which is based on virtual synchronous converter (VSCon) technique is been developed. This technique does not require any phase locked loop (PLL) circuit as an external control structure for the …
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Distributed synchronization algorithms for wireless sensor networks
The ability to distribute time and frequency among a large population of interacting agents is of interest for diverse disciplines, inasmuch as it enables to carry out complex cooperative tasks. In a wireless sensor network (WSN), time/frequency synchronization allows the implementation of …
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Robust Wireless Communications with Applications to Reconfigurable Intelligent Surfaces
… encoded JSCC code words to the baseband of the frequency domain in order to enable time/frequency synchronization as well as to mitigate fading using robust estimation theory. Additionally, I perform robust statistical signal processing on the high-dimensional JSCC code showing significant noise …
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Capacity, coding and interference cancellation in multiuser multicarrier wireless communications systems
… of research during the last decade. Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier modulation generated with the inverse Discrete Fourier Transform, which has been adopted for standards in wireless and wire-line communications. Multiuser wireless systems using multicarrier …
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Current source based wind energy conversion system
… pulse angle changes and a fixed switching frequency over the full modulation index range. These attributes show that the proposed BTB-DPWM-CSC WECS is suited for multi-megawatt applications. The second and third WECSs are based on modified three-phase and dual three-phase BTB-PWM-CSCs. …
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Characterization and Application of Wide-Band-Gap Devices for High Frequency Power Conversion
… (Si) and be used to pursue groundbreaking high-frequency, high-efficiency, and high-power-density power conversion. The switching performance of cascode GaN HEMT is studied at first. An accurate behavior-level simulation model is developed with comprehensive consideration of the impacts of …
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Radio-Location Techniques for Localization and Monitoring Applications. A study of localisation techniques, using OFDM system under adverse channel conditions and radio frequency identification for object identification and movement tracking
… of OFDM signal by mitigating the effect of frequency offset synchronization to give error-free data at the receiver, good angle of arrival accuracy and improved SNR performance. The full system simulation to explore optimum values such as channel estimation and AoA including the antenna …