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 27 for “"impulsive noise"”.
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Robust speech filtering in impulsive noise environments
… a new robust filtering technique that suppresses impulsive noise in speech signals. The method makes use of Projection Statistics based on medians to detect segments of speech with impulses. The autoregressive model employed to smooth out the speech signal is identified by means of a robust …
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Robust Blind Spectral Estimation in the Presence of Impulsive Noise
… and when the spectrum is also contaminated by Impulsive Noise (IN). Power Line Communication (PLC) is an example of a communication environment where IN is a concern because power lines were not designed with the intent to transmit communication signals. There are many different noise models …
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Measurements and models of radio frequency impulsive noise inside buildings
This thesis presents results of average and impulsive noise measurements inside five office buildings and retail stores. Measurements were made at 918 MHz, 2.44 GHz, and 4.0 GHz using a superheterodyne receiver with 70 dB dynamic range and a 3-dB RF bandwidth of 40 MHz. Omni-directional and …
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Man-made impulsive noise on the 137 MHz VHF LEOSAT channel
… been determined by thermal background noise produced internally as well as externally to the radio receiver. Most recently, however, man-made noise has become the dominant source of link interference at VHF frequencies and below. This thesis examines the statistical behavior of man-made …
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Long polyphase sequences for adaptive mmse detector in asynchronous cdma plc network with impulsive noise
… response, and the characteristics of the channel noise. In this thesis, a powerline channel model is proposed, which takes into account the noise generated in the network as well as the frequency attenuation profile of the unmatched network. The proposed model is based on a channel measurement …
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Iterative Memoryless Non-linear Estimators of Correlation for Complex-Valued Gaussian Processes that Exhibit Robustness to Impulsive Noise
… a finite number of observations. Non-Gaussian, impulsive observation noise following probability density functions with thick tails, which often occurs in practice, can bias this estimator, rendering classical time series analysis methods ineffective. This work examines the robustness of two …
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ΜΕΛΕΤΗ ΚΑΙ ΑΞΙΟΛΟΓΗΣΗ ΤΗΣ ΣΥΜΠΕΡΙΦΟΡΑΣ Μ-ARY ΣΥΜΒΑΤΩΝ PSK ΣΥΣΤΗΜΑΤΩΝ ΨΗΦΙΑΚΗΣ ΔΙΑΜΟΡΦΩΣΗΣ ΜΙΚΡΟΚΥΜΑΤΙΚΩΝ ΔΟΡΥΦΟΡΙΚΩΝ ΖΕΥΞΕΩΝ ΠΑΡΟΥΣΙΑ ΠΑΡΕ...
… CHARACTERIZED BY THE PRESENCE OF GAUSSIAN NOISE, INTERFERENCE AND/OR FADING HAS BEEN EXTENSIVELY ANALYSED. HOWEVER IT IS WELL KNOWN THAT CERTAIN COMPONENTS OF NOISE ORIGINATING IN VARIOUS COMMUNICATION CHANNELS OF TEN EXHIBIT IMPULSIVECHARACTERISTICS, I.E. BURSTS OF LARGE AMPLITUDE IN …
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Measuring Noise in the VHF Band and Its Effect on Low SNR Signal Detection
… is computationally simple to implement. Man-made noise, impulsive in nature, has also become more prevalent with the widespread use of electronic devices. In this thesis, we took measurements of man-made impulsive noise in the broadcast digital television bands to measure its presence, power, and …
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Robust compression of multispectral remote sensing data
… containing information about the ideal, noiseless spectrum, and by exploiting inter-channel correlations in the data. The algorithms operate on calibrated data modeled as the sum of the ideal spectrum, and an independent noise component due to sensor noise, calibration error, and, …
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Noise blanker for land mobile radio systems
… are squeezed into the same bandwidth. However, noise and impulsive noise levels on the radio path are increasing and this reduces quality. This project seeks to use advanced signal processing to develop a generic noise blanking technique suitable for a new generation of mobile radio equipment to …
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High Speed Turbo Tcm Ofdm For Uwb And Powerline System
… to jammer signals, and its robustness to impulsive noise in power line channel. The main idea behind OFDM is to split the transmitted data sequence into N parallel sequences of symbols and transmit on different frequencies. This structure has the particularity to enable a simple …
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Robust Speech Filter And Voice Encoder Parameter Estimation using the Phase-Phase Correlator
… while providing, in the absence of im- pulsive noise, natural sounding synthetic speech signals. This good performance has been achieved via the use of a maximum likelihood parameter estimation of an auto-regressive model of order ten that best fits the speech signal under the assumption that …
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Detection of signals corrupted by the combination of Gaussian and Non-Gaussian noise
The detection of signals in the presence of noise is one of the most basic and important problems encountered by communication engineers. Although the literature abounds with analyses of communications in Gaussian noise, relatively little work has appeared dealing with communications in …
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Implementation of Directional Median Filtering using Field Programmable Gate Arrays
… technique which is effective in removing impulsive noise from data. In this thesis, directional median filtering has been implemented using cumulative histogram of samples in several directions. Different methods to implement directional median filtering have been proposed. The filtered …
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Signal estimation techniques using Lp-norm optimal stack filters with applications to image and video processing
… involve restoration of signals corrupted with impulsive noise, when sharp edges are to be preserved. Various subclasses of stack filters, such as the rank order operators and the weighted median filters, show a great deal of promise in finding commercial applications in image processing and …
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Performance of cooperative space time coding with spatially correlated fading and imperfect channel estimation
… channel estimation in Gaussian as well as impulsive noise is presented. Closed form expressions for the pairwise error probability conditioned on the estimated channel gains are derived by assuming the components of the received vector are independent given the estimated channel gains. An …
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Turbo coding and equalization for wireless communication systems
… channel suffers performance degradation due to impulsive noise generated by electrical appliances. This thesis analysed a set of filter design criteria based on minimizing the bit error probability of impulse noise using digital smear filter.
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Performance of Ds/ssma Communications in Impulsive Channels (Nongaussian, Hard Limiter)
… interference, and additive channel noise, which is attributed to impulsive noise sources in the environment. The contribution of multiple-access interference is examined by considering K users transmitting simultaneously over a linear channel using the binary PSK direct-sequence SSMA …
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System (for) Tracking Equilibrium and Determining Incline (STEADI)
… used to amplify/enhance the signal by removing impulsive noise while preserving the signal shape while the High pass filter is used to emphasise transitions in the signal. Then, in order to recognize a fall event, our STEADI system implements two methods that are a simple threshold analysis to …
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Robust hardware elements for weightless artificial neural networks
… thus increasing robustness in the presence of impulsive noise. Hierarchies formed from these neural elements are studied and a weightless probabilisitic activation function proposed for non-deterministic applications. Neuroram, an auto-associative memory created using these weightless neurons …
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