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 18 of 18 for “"Carrier frequency offset"”.
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Analysis and mitigation of carrier frequency offset for uplink of OFDMA
Orthogonal Frequency Division Multiplexing (OFDM) is being used in many wireless standards because of its immunity to multipath fading, high spectral efficiency and simple implementation, making it suitable for high data rate multimedia wireless applications. One of the significant drawbacks of the …
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Spectrally Modulated Spectrally Encoded Framework Based Cognitive Radio in Mobile Environment
… users (SUs) are non-contiguous, and multi-carrier transmission technologies become the natural solution to occupy those non-contiguous bands.Non-contiguous multi-carrier based modulations, such as NC-OFDM (non-contiguous Orthogonal Frequency Division Multiplexing), NC-MC-CDMA …
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A new data rotation syncrhonization scheme for CP based OFDM systems
… a new data rotation scheme for symbol timing and carrier frequency offset (CFO) estimation of orthogonal frequency-division multiplexing (OFDM) systems. We first analyze Beeka??s cyclic prefix (CP) based joint ML estimator [2] and find that its performance can be improved when the average energy …
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Digital Signal Processing for Front-end Non-idealities in Coherent Optical OFDM system
… non-idealities in CO-OFDM systems, including carrier frequency offset, linear phase noise and IQ mismatch. Firstly, we propose a novel frequency offset compensation method, which is successfully demonstrated through experiment. Our algorithm achieves the widest estimation range with one …
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On the performance and capacity of space-time block coded multicarrier CDMA communication systems
… technology, space-time block coded (STBC) multicarrier (MC-) CDMA, for next generation of wireless mobile communication systems. The thesis first investigates the bit error ratio (BER) performance and bandwidth efficiency of STBC MC-CDMA systems in the presence of carrier frequency offset (CFO). …
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Blind CFO Estimation for Zero-Padded OFDM over Underwater Acoustic Channels
… and complexity of three existing blind carrier-frequency-offset (CFO) estimators when they are applied to estimate the residual Doppler shift for zero-padded OFDM transmissions over underwater acoustic channels: the null subcarrier based method, the O-M algorithm, and the Y-G algorithm. …
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Frequency Domain Independent Component Analysis Applied To Wireless Communications Over Frequency-selective Channels
In wireless communications, frequency-selective fading is a major source of impairment for wireless communications. In this research, a novel Frequency-Domain Independent Component Analysis (ICA-F) approach is proposed to blindly separate and deconvolve signals traveling through …
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Node localization in underwater sensor networks (UWSN)
… PNs in severely dispersive channels and when the carrier frequency offset (CFO) is high"--Abstract, page iv.</p>
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An Investigation of Orthogonal Wavelet Division Multiplexing Techniques as an Alternative to Orthogonal Frequency Division Multiplex Transmissions and Comparison of Wavelet Families and Their Children
… and the difficulty of modulating signals across carriers, represent significant challenges. Every modulation scheme used to date has had limitations, and the use of the Discrete Fourier Transform in OFDM (Orthogonal Frequency Division Multiplex) is no exception. The restriction on further …
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Advanced methods in automatic modulation classification for emerging technologies
… combining (MRC) to increase the accuracy of both carrier frequency offset (CFO) estimation and likelihood function calculation in channel fading. In fact, double CFO estimations are executed in this classifier. With the first the unknown CFO, phase offsets and amplitudes are estimated as …
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Modeling and Analysis of Synchronization Schemes for the TDMA Based Satellite Communication System
… in satellite communications. Although single-carrier (SC) modulation techniques has been mostly employed in the TDMA satellite communication system, multi-carrier modulation techniques, like orthogonal frequency division multiplexing (OFDM), are also promising candidates for the future high …
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DOCSIS 3.1 cable modem and upstream channel simulation in MATLAB
… increased the signal processing to include frequency diplexers. CATV service providers began to expand the bandwidth of their networks in the late 90’s by switching from analogue to digital technology. In an effort to regulate the manufacturing of new digital equipment and ensure …
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I/Q imbalance mitigation for space-time block coded communication systems
… time domain, hence a mirror-image term in the frequency domain, in the data structure. Consequently, I/Q imbalance increases the symbol error rate (SER) drastically in MIMO STBC or STBC MIMO orthogonal frequency division multiplexing (OFDM) communication systems, where both the signal and its …
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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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Design and Optimization of 5G and Beyond Hybrid Communication Systems
… systems, where the synchronization involves the carrier frequency offset estimation and compensation, and the calibration involves mitigating reciprocity mismatches in digital and analog RF chains of the access points (APs) implementing hybrid beamforming, enabling efficient downlink channel …