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 15 of 15 for “"timing synchronization"”.
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Architectures for Symbol Timing Synchronization in MIMO Communications
Maximum likelihood symbol timing estimation for communication over a frequency non-selective MIMO fading channel is developed. The cases of known data (data-aided estimation) and unknown data (non-data-aided estimation) together with known channel and unknown channel are considered. The analysis …
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A comparison of timing methods in orthogonal frequency division multiplexing (OFDM) systems
… (ICI). Many techniques exist to realize timing synchronization in OFDM systems. In this thesis, the need for timing synchronization, the timing errors, and the performance of different techniques under a variety of mobile channel models (indoor and outdoor) are investigated, and …
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All-semiconductor High Power Mode-locked Laser System
All-optical synchronization and its application in advanced optical communications have been investigated in this dissertation. Dynamics of all-optical timing synchronization (clock recovery) using multi-section gain-coupled distributed-feedback (MS-GC DFB) lasers are discussed. A record speed of …
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Analysis Of Time Synchronization Errors In High Data Rate Ultrawideban
… The purpose of this Thesis is to estimate the timing accuracies required with such systems in order to achieve Bit Error Rates (BER) of the order of magnitude of 10-12 and thereby avoid overloading the correction of irreducible errors due to misaligned timing errors to a small absolute number …
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Toward single-cycle optical pulses
… To achieve single-cycle optical pulses by active synchronization, three major steps are required. Firstly, two very stable and broadband mode-locked lasers with overlapping spectra are necessary. Secondly, a tight timing synchronization with timing jitter under one-tenth of the synthesized …
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Next Generation Frequency Disturbance Recorder Design and Timing Analysis
… solution. With Internet connectivity and GPS timing synchronization, the FDR provides high accuracy frequency, voltage magnitude and voltage angle data to the remote servers. Although the current FDR design is up to the standard in terms of the measurement accuracy and portability, it is of …
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A Hardware Implementation of a Coherent SOQPSK-TG Demodulator for FEC Applications
… details for data sequence detection, symbol timing synchronization, carrier phase synchronization, and block recovery are described. This decision-directed demodulator is based on maximum likelihood principles, and is efficiently implemented by the soft output Viterbi algorithm (SOVA). The …
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Integrated waveguide devices for mode-locked lasers
… source of optical pulses with intrinsically low timing jitter, and as such have a broad range of important applications, both as sources of low-noise microwave signals and as the key enabling technology for optical frequency combs. Integrating such laser systems onto a chip using silicon …
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Node Selection, Synchronization and Power Allocation in Cooperative Wireless Networks
… orders are studied. Additionally, the effect of timing synchronization errors on the symbol error rate performance is investigated. Moreover, a sum-of-rates maximizing optimal power allocation is proposed. Relay selection is also proposed to improve the total achievable rate and mitigate the …
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Radio frequency digital to analog converter
… Inter-symbol interference (ISI), imperfect timing synchronization and clock jitter are all culprits. A DAC output current controlled by an oscillating waveform is proposed to mitigate the effects of the switching distortion. The oscillating waveform should be a multiple (k*fs) of the …
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High-precision optical and microwave signal synthesis and distribution
… by coherent superposition of mode-locked lasers. Timing and phase synchronization of ultrabroadband Ti:sapphire and Cr:forsterite mode-locked lasers is studied. Subfemtosecond (<0.4 fs) timing synchronization over 12 h is demonstrated. In addition to the timing lock, phase synchronization to a …
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High Accuracy Real-time GPS Synchronized Frequency Measurement Device for Wide-area Power Grid Monitoring
… high-voltage inputs. An embedded 12-channel timing GPS receiver has been integrated to provide an accurate timing synchronization signal, UTC time stamp, and unit location. This research work also addresses the harmonics, voltage swing and other noise components' impacts on the measurement …
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Cooperative Detection and Network Coding in Wireless Networks
… the number of communicating nodes and the timing synchronization errors is analyzed and provided as a network design guideline. With STNC, it is illustrated that cooperative diversity gains are fully exploited per node and significant performance improvements are achieved. It is concluded …
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Sub-femtosecond precision timing distribution, synchronization and coherent synthesis of ultrafast lasers
… optical pulse trains, with respect to pulse timing and phase. First, analytical analysis of the balanced optical cross-correlator (BOC) for attosecond precision pulse timing measurement is presented for both short and long crystal devices. It is found that the sensitivity of the long crystal …