Dissertations / Theses: 'Wideband signals'

1

Zhao, Lu. "Optical transmission of wideband video signals using SWFM." Thesis, University of Manchester, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317775.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Karousos, A. "The distortion of ultra-wideband signals in the environment." Thesis, University of Surrey, 2008. http://epubs.surrey.ac.uk/843691/.

Full text

Abstract:

The need for higher data rates in wireless communication systems and the lack of available frequency space has led the researchers in developing new technologies, such as UWB. Ultra-wideband systems utilise signals with very short duration and very large bandwidth, from which the benefits are twofold; more information can be exchanged and coexistence with narrowband technologies is possible, as such systems perceive UWB as noise and interference is thus avoided. The increased bandwidth offers multipath resolution, which when properly treated can enhance system's performance and reliability. Signal distortion however, may prohibit system's optimum performance. It is more efficiently treated directly into the time-domain. The lack of information on the propagation of UWB signals in a complex environment, other than single reflected and diffracted waves, was tackled in this work. Easy-to-use and accurate reflection and transmission coefficients for a wave impinging on a dielectric slab were deduced. An algorithm for the prediction of a signal, which is multiply diffracted waves on an number of absorbing knife-edges and/or imperfect conducting wedges was also implemented. The algorithm accurately took into account the arisen higher-order fields, that are created in such cases, according to the Uniform Theory of Diffraction. A tool for signal prediction in a complex environment was constructed, based on the environment discretisation into tiles and segments. Its validity was initially tested for the narrowband case, by comparing its predictions with measurement, with a quite good agreement. Then, it was modified, so as to incorporate the dispersive nature of the channel. This was accomplished in the time-domain, where the TD ray-trace model not only predicts the arrival times of the multipaths but also their shape. The results were compared with measurement data collected with a VNA.

APA, Harvard, Vancouver, ISO, and other styles

3

Jackson, Kevin. "Blind Front-end Processing of Dynamic Multi-channel Wideband Signals." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/4692.

Full text

Abstract:

In wireless digital communications, the sender and receiver typically know the modulation scheme with which they will be communicating. Automatic modulation identification is the ability to identify the modulation in a communication system with little to no prior knowledge of the modulation scheme. Many techniques for modulation identification operate on many assumptions including that the input signal is base-banded, the carrier frequency is known and that the signal is narrow-band (i.e. neighboring signals in the wide-band are excluded). This work provides the blind processing of an arbitrary wide-band signal to allow such assumptions. The challenges of such a front-end or pre-processor include detecting signals which can appear at any frequency, with any band-width at any given time and for any arbitrary duration. This work takes as its input a wide-band signal with a random number of sub-signals, each turning on and o at random times and each at random locations in the frequency domain. The output of the system is a collection of signals corresponding to each sub-signal brought down to base-band, isolated in the frequency and time domains, nominally sampled and with estimates of key parameters.

APA, Harvard, Vancouver, ISO, and other styles

4

Weiler, Ruediger Matthias. "Architectures and techniques for improved receiver performance with wideband navigation signals." Thesis, University of Surrey, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.510590.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Kassem, Wafaa Ibrahim. "Direction of arrival estimation and beamforming for narrowband and wideband signals." Thesis, University of Leeds, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418235.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Issa, Abd Al-Kareem M. "Investigation of the pulse time modulation techniques for transmission of wideband signals." Thesis, Sheffield Hallam University, 1997. http://shura.shu.ac.uk/3094/.

Full text

Abstract:

The choice of the modulation format is the principle factor in realising a highperformance bandwidth efficient communication system at an acceptable cost and complexity. Pulse time modulation technique represents an attractive alternative to purely digital or purely analogue modulation schemes which has received considerable attention over the years. But very little work has been reported on pulse slope modulation. In this work a pulse slope modulation introduced and full wavefonn characteristics is given. A simple novel receiver has been proposed, which is based on converting the PSM waveform into a PAM waveform by sampling the received PSM signal at the rise time interval. This design eliminates the use of a differentiator and a voltage slicer adopted in the classical demodulation technique, and it offers simplicity and improved noise performance. A new signal-t-noise formula has been presented for the first time thus enabling users to predict the system noise performance. Experimental results have shown excellent agreement to within + 1 dB with theoretical predictions using the new formula. Results obtained show the potential of PSM in tenns of simplicity and better noise perfonnance compared to its counter part pulse amplitude modulation. Although PTM has many advantages over analogue and digital schemes when employed as a single channel system, it becomes a challenge when multiplexing is involved. Isochronous PTM schemes are suitable while the anisochronous schemes are not. One solution to overcome this problem is to adopt a hybrid or compound modulation technique, where both isochronous and anisochronous schemes can be combined. Compound frequency and width modulation (CPFWM) is one such a scheme which offers bandwidth efficiency, simplicity and low cost over the more commonly used multiplexed techniques. Detailed investigation of CPFWM has been given and in an expression for its spectrum has been developed. The results obtained have been clarified practically and by means of computer simulation to within + 1 dB. In CPFWM, cross talk in the PFM and pWM channels are due to width modulation and frequency modulation, respectively. The main cause of cross talk is the carryover energy from one edge to the next edge. This effect is studied and he results obtained for the cross talk are compared with the predicted data showing an agreement to within + 1 dB. Results were also compared with time division multiplexed pulse position modulation, showing comparable performance and under certain conditions CPFWM offering better performance. Noise performance of PFM and PWM channels has been theoretically and experimentally investigated. It has been shown that PFM is superior to PWM over a wide range of modulation indices and pulse characteristics. When both channels are identical in bandwidth and modulation conditions, PFM offers a 7 dB improvement compared to PWM channel. The noise perfonnance of CPFWM system is also compared with digital and analogue modulation schemes. For 25 dB CNR CPFWM offers a 40 dB SNR which is 20 dB higher than amplitude modulation, 1 7 dB lower than PCM system. At CNR > 35 dB its performance approaches that of PCM system. Thus showing the potential of the scheme.

APA, Harvard, Vancouver, ISO, and other styles

7

Dimopoulos, Ilias K. "Simultaneous wideband transmission of five FDM signals over a fiber optic link." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/27268.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Li, Chang. "Non-contract Estimation of Respiration and Heartbeat Rate using Ultra-Wideband Signals." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/34990.

Full text

Abstract:

The use of ultra-wideband (UWB) signals holds great promise for remote monitoring of vital-signs which has applications in the medical, for first responder and in security. Previous research has shown the feasibility of a UWB-based radar system for respiratory and heartbeat rate estimation. Some simulation and real experimental results are presented to demonstrate the capability of the respiration rate detection. However, past analysis are mostly based upon the assumption of an ideal experiment environment. The accuracy of the estimation and interference factors of this technology has not been investigated.

This thesis establishes an analytical framework for the FFT-based signal processing algorithms to detect periodic bio-signals from a single target. Based on both simulation and experimental data, three basic challenges are identified: (1) Small body movement during the measurement interval results in slow variations in the consecutive received waveforms which mask the signals of interest. (2) The relatively strong respiratory signal with its harmonics greatly impact the detection of heartbeat rate. (3) The non-stationary nature of bio-signals creates challenges for spectral analysis. Having identified these problems, adaptive signal processing techniques have been developed which effectively mitigate these problems. Specifically, an ellipse-fitting algorithm is adopted to track and compensate the aperiodic large-scale body motion, and a wavelet-based filter is applied for attenuating the interference caused by respiratory harmonics to accurately estimate the heartbeat frequency. Additionally, the spectrum estimation of non-stationary signals is examined using a different transform method. Results from simulation and experiments show that substantial improvement is obtained by the use of these techniques.

Further, this thesis examines the possibility of multi-target detection based on the same measurement setup. Array processing techniques with subspace-based algorithms are applied to estimate multiple respiration rates from different targets. The combination of array processing and single- target detection techniques are developed to extract the heartbeat rates. The performance is examined via simulation and experimental results and the limitation of the current measurement setup is discussed.
Master of Science

APA, Harvard, Vancouver, ISO, and other styles

9

Liu, Feiran. "High Frequency Resolution Adaptive Thresholding Wideband Receiver System." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1451042587.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Sargeant, H. "PREDETECTION RECORDING TECHNIQUES FOR GPS SIGNALS." International Foundation for Telemetering, 1986. http://hdl.handle.net/10150/615545.

Full text

Abstract:

International Telemetering Conference Proceedings / October 13-16, 1986 / Riviera Hotel, Las Vegas, Nevada
Predetection recording of spread-spectrum (SS) signals such as GPS transmissions is a desirable objective for both users and developers of equipment designed to receive such signals. (GPS user-equipment development is a lengthy process during which signal simulators are only partially useful.) Upon playback, GPS signals are used by the same or modified receivers so that acquisition, processing, detection and tracking loops can be altered to optimize the receiver parameters. Development of predetect SS signal recording systems is difficult to achieve in practice. Such systems not only must be of suitable phase linearity to preserve the signal content to be extracted but sometimes must also preserve the exact signal-to-noise ratio (SNR) characteristics of the recorded signals. Existing conventional test equipment is unsuitable for deriving value judgments of the quality of a predetect recording system’s output because the SS signal has a negative SNR. This paper reveals that it is possible to use, for this purpose, tape recorders now available on many test ranges in combination with auxiliary equipment similar to that designed for the U.S. Navy’s TRIDENT Program (recording C/A-code data from in-flight missile translators). The basic techniques are described in some detail to enable potential users to understand the necessary equipment concepts and evaluate the author’s approach in terms of their own applications.

APA, Harvard, Vancouver, ISO, and other styles

11

Davies, Jonathan Gary. "Propagation of radio signals into and within multi-storey buildings at 900 MHz and 1800 MHz." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367236.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

DeRieux, David A. "Investigation of spectral-based techniques for classification of wideband transient signals in additive white Gaussian noise." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA282954.

Full text

Abstract:

Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, March 1994.
Thesis advisor(s): Ralph Hippenstiel, Monique P. Fargues. "March 1994." Includes bibliographical references. Also available online.

APA, Harvard, Vancouver, ISO, and other styles

13

Straessle, Gregory C. "Performance analysis and enhancements for the music sub-space direction-finding algorithm in the presence of wideband signals." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/44676.

Full text

Abstract:

Approved for public release; distribution is unlimited
Includes supplementary materials.
The collection of signals intelligence via passive direction finding and geolocation of radio frequency signals is of great concern to the military for its contribution to the development of battlespace awareness. Basic subspace direction finding techniques provide a method of determining the direction-of-arrival (DOA) of multiple signals on an array of receivers, but they have an inherent limitation in that they are narrowband by design. The impact of various signal frequencies, bandwidths, and signal to noise ratios present in the source signals received by a sparse array using the multiple signals classification (MUSIC) subspace direction-finding algorithm are evaluated in this thesis. Additionally, two performance enhancements are presented: one that reduces the MUSIC computational load and one that provides a method of utilizing collector motion to resolve DOA ambiguities.

APA, Harvard, Vancouver, ISO, and other styles

14

Gupta, Shalabh. "Photonic time stretch analog-to-digital conversion for high resolution and real-time burst sampling of ultra-wideband signals." Diss., Restricted to subscribing institutions, 2009. http://proquest.umi.com/pqdweb?did=2026639441&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Völcker, Björn. "Performance Analysis of Parametric Spectral Estimators." Doctoral thesis, KTH, Signals, Sensors and Systems, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3323.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Malekizandi, Mohammadreza [Verfasser], Franko [Akademischer Betreuer] Küppers, and Manfred [Akademischer Betreuer] Berroth. "Generation and Transmission of Optical Ultra-wideband Signals for Optical Fiber and Wireless Communication Links / Mohammadreza Malekizandi ; Franko Küppers, Manfred Berroth." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2018. http://d-nb.info/116301351X/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Khodjet-Kesba, Mahmoud. "Automatic target classification based on radar backscattered ultra wide band signals." Thesis, Clermont-Ferrand 2, 2014. http://www.theses.fr/2014CLF22506/document.

Full text

Abstract:

L’objectif de cette thèse est la classification automatique des cibles (ATC) en utilisant les signaux rétrodiffusés par un radar ultra large bande (UWB). La classification des cibles est réalisée en comparant les signatures des cibles et les signatures stockées dans une base de données. Premièrement, une étude sur la théorie de diffusion nous a permis de comprendre le sens physique des paramètres extraits et de les exprimer mathématiquement. Deuxièmement, des méthodes d’extraction de paramètres sont appliquées afin de déterminer les signatures des cibles. Un bon choix des paramètres est important afin de distinguer les différentes cibles. Différentes méthodes d’extraction de paramètres sont comparées notamment : méthode de Prony, Racine-classification des signaux multiples (Root-MUSIC), l’estimation des paramètres des signaux par des techniques d’invariances rotationnels (ESPRIT), et la méthode Matrix Pencil (MPM). Troisièmement, une méthode efficace de classification supervisée est nécessaire afin de classer les cibles inconnues par l’utilisation de leurs signatures extraites. Différentes méthodes de classification sont comparées notamment : Classification par la distance de Mahalanobis (MDC), Naïve Bayes (NB), k-plus proches voisins (k-NN), Machines à Vecteurs de Support (SVM). Une bonne technique de classification doit avoir une bonne précision en présence de signaux bruités et quelques soit l’angle d’émission. Les différents algorithmes ont été validés en utilisant les simulations des données rétrodiffusées par des objets canoniques et des cibles de géométries complexes modélisées par des fils minces et parfaitement conducteurs. Une méthode de classification automatique de cibles basée sur l’utilisation de la méthode Matrix Pencil dans le domaine fréquentiel (MPMFD) pour l’extraction des paramètres et la classification par la distance de Mahalanobis est proposée. Les résultats de simulation montrent que les paramètres extraits par MPMFD présentent une solution plausible pour la classification automatique des cibles. En outre, nous avons prouvé que la méthode proposée a une bonne tolérance aux bruits lors de la classification des cibles. Enfin, les différents algorithmes sont validés sur des données expérimentales et cibles réelles
The objective of this thesis is the Automatic Target Classification (ATC) based on radar backscattered Ultra WideBand (UWB) signals. The classification of the targets is realized by making comparison between the deduced target properties and the different target features which are already recorded in a database. First, the study of scattering theory allows us to understand the physical meaning of the extracted features and describe them mathematically. Second, feature extraction methods are applied in order to extract signatures of the targets. A good choice of features is important to distinguish different targets. Different methods of feature extraction are compared including wavelet transform and high resolution techniques such as: Prony’s method, Root-Multiple SIgnal Classification (Root-MUSIC), Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) and Matrix Pencil Method (MPM). Third, an efficient method of supervised classification is necessary to classify unknown targets by using the extracted features. Different methods of classification are compared: Mahalanobis Distance Classifier (MDC), Naïve Bayes (NB), k-Nearest Neighbors (k-NN) and Support Vector Machine (SVM). A useful classifier design technique should have a high rate of accuracy in the presence of noisy data coming from different aspect angles. The different algorithms are demonstrated using simulated backscattered data from canonical objects and complex target geometries modeled by perfectly conducting thin wires. A method of ATC based on the use of Matrix Pencil Method in Frequency Domain (MPMFD) for feature extraction and MDC for classification is proposed. Simulation results illustrate that features extracted with MPMFD present a plausible solution to automatic target classification. In addition, we prove that the proposed method has better ability to tolerate noise effects in radar target classification. Finally, the different algorithms are validated on experimental data and real targets

APA, Harvard, Vancouver, ISO, and other styles

18

Nguyen, Linh Trung. "Estimation and separation of linear frequency- modulated signals in wireless communications using time - frequency signal processing." Queensland University of Technology, 2004. http://eprints.qut.edu.au/15984/.

Full text

Abstract:

Signal processing has been playing a key role in providing solutions to key problems encountered in communications, in general, and in wireless communications, in particular. Time-Frequency Signal Processing (TFSP) provides eective tools for analyzing nonstationary signals where the frequency content of signals varies in time as well as for analyzing linear time-varying systems. This research aimed at exploiting the advantages of TFSP, in dealing with nonstationary signals, into the fundamental issues of signal processing, namely the signal estimation and signal separation. In particular, it has investigated the problems of (i) the Instantaneous Frequency (IF) estimation of Linear Frequency-Modulated (LFM) signals corrupted in complex-valued zero-mean Multiplicative Noise (MN), and (ii) the Underdetermined Blind Source Separation (UBSS) of LFM signals, while focusing onto the fast-growing area of Wireless Communications (WCom). A common problem in the issue of signal estimation is the estimation of the frequency of Frequency-Modulated signals which are seen in many engineering and real-life applications. Accurate frequency estimation leads to accurate recovery of the true information. In some applications, the random amplitude modulation shows up when the medium is dispersive and/or when the assumption of point target is not valid; the original signal is considered to be corrupted by an MN process thus seriously aecting the recovery of the information-bearing frequency. The IF estimation of nonstationary signals corrupted by complex-valued zero-mean MN was investigated in this research. We have proposed a Second-Order Statistics approach, rather than a Higher-Order Statistics approach, for IF estimation using Time-Frequency Distributions (TFDs). The main assumption was that the autocorrelation function of the MN is real-valued but not necessarily positive (i.e. the spectrum of the MN is symmetric but does not necessary has the highest peak at zero frequency). The estimation performance was analyzed in terms of bias and variance, and compared between four dierent TFDs: Wigner-Ville Distribution, Spectrogram, Choi-Williams Distribution and Modified B Distribution. To further improve the estimation, we proposed to use the Multiple Signal Classification algorithm and showed its better performance. It was shown that the Modified B Distribution performance was the best for Signal-to-Noise Ratio less than 10dB. In the issue of signal separation, a new research direction called Blind Source Separation (BSS) has emerged over the last decade. BSS is a fundamental technique in array signal processing aiming at recovering unobserved signals or sources from observed mixtures exploiting only the assumption of mutual independence between the signals. The term "blind" indicates that neither the structure of the mixtures nor the source signals are known to the receivers. Applications of BSS are seen in, for example, radar and sonar, communications, speech processing, biomedical signal processing. In the case of nonstationary signals, a TF structure forcing approach was introduced by Belouchrani and Amin by defining the Spatial Time- Frequency Distribution (STFD), which combines both TF diversity and spatial diversity. The benefit of STFD in an environment of nonstationary signals is the direct exploitation of the information brought by the nonstationarity of the signals. A drawback of most BSS algorithms is that they fail to separate sources in situations where there are more sources than sensors, referred to as UBSS. The UBSS of nonstationary signals was investigated in this research. We have presented a new approach for blind separation of nonstationary sources using their TFDs. The separation algorithm is based on a vector clustering procedure that estimates the source TFDs by grouping together the TF points corresponding to "closely spaced" spatial directions. Simulations illustrate the performances of the proposed method for the underdetermined blind separation of FM signals. The method developed in this research represents a new research direction for solving the UBSS problem. The successful results obtained in the research development of the above two problems has led to a conclusion that TFSP is useful for WCom. Future research directions were also proposed.

APA, Harvard, Vancouver, ISO, and other styles

19

Uthansakul, Monthippa. "Wideband beamforming employing fully spatial signal processing /." [St. Lucia, Qld.], 2006. http://adt.library.uq.edu.au/public/adt-QU20070503.135836/index.html.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Ma, Shing Yuan. "Analog and mixed-signal DFT using wideband undersampling." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq30513.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Akpa, Marcellin. "Tree structure filter bank for wideband signal processing." Thesis, University of Ottawa (Canada), 1995. http://hdl.handle.net/10393/10407.

Full text

Abstract:

A N-parallel branches maximally decimated filter bank is generally implemented using the polyphase components implementation. In this case, a N-th band lowpass filter is designed and its polyphase components are derived to constitute the branch 'subfilters.' This approach uses a N x N FFT matrix that will be the source of the complex (numbers) operations. Obviously, when the number of branches is equal to 2, the computations remain real. In a tree structure filter bank, the computations remain real with or without polyphase implementation. When the polyphase implementation is used, the branch signals at each stage are computed using a set of 2 x 2 FFT matrices leading to real computations. In this thesis, a new implementation approach based on the tree structured is proposed. The derivation of the structure is based on the equivalent parallel structure implementation of the tree structured filter bank. It uses the polyphase components of a given half-band lowpass filter (real coefficients) followed by a N x N Hadamard matrix. The computations, as in the original tree structured filter bank, remain real. A simplified version of the structure is a 'tree structure' followed by an N x N Hadamard matrix. A comparison between this new structure and the N parallel branch maximally decimated filter bank is made based on reconstruction error, computation complexity and processing delay.

APA, Harvard, Vancouver, ISO, and other styles

22

Shan, Rafi-Us. "Header compression and signal processing for wideband communication systems." Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.664453.

Full text

Abstract:

This thesis is dedicated to the investigation, development and practical verification of header compression and signal processing techniques over TErrestrial Trunked RAdio (TETRA), TETRA Enhanced Data Services (TEDS) and Power Line Communication (PLC). TETRA release I is a narrowband private mobile radio technology used by safety and security organizations, while TEDS is a widebandsystem. With the introduction of IP support, TEDS enables multimedia based applications and services to communicate across communication systems. However the IP extension for TEDS comes at a cost of significant header contributions with the payload. With small application payloads and fast rate application traffic profiles, the header contribution in the total size of the packet is considerably more than the actual application payload. This overhead constitutes the considerable slot capacity at the physical layer of TEDS and PLC. Advanced header compression techniques such as Robust Header Compression (RoHC) compress the huge header sizes and offer significant compression gain without compromising quality of service (QoS). Systems can utilize this bandwidth to transmit more information payload than control information. In this study, the objective is to investigate the integration of RoRC in TEDS and design a novel IPv6 enabled protocol stack for PLC with integrated RoHC. The purpose of the study is also to investigate the throughput optimization technique such as RoHC over TEDS and PLC by simulating different traffic profile classes and to illustrate the benefit of using RoHC over TEDS and PLC. The thesis also aims to design and simulate the TEDS physical layer for the purpose of investigating the performance of higher order modulation schemes. Current TEDS, standards are based on the transmission frequencies above 400MHz range, however with delays in the standardization of broadband TETRA, it is important to explore all possible avenues to extend the capacity of the system. The research concludes the finding of the application of RoHC for TEDS and PLC, against different traffic classes and propagation channels. The benefit of using RoHC in terms of saving bandwidth, slot capacity and other QoS parameters is presented along with integration aspects into TEDS and PLC comnunication stacks. The study also presents the TEDS physical layer simulation results for modulation schemes and transmission frequency other than specified in the standard. The research results presented in this thesis have been published in international symposiums and professional journals. The application of the benefits of using RoHC for TEDS has been proposed to the ETSI TETRA for contribution to the TETRA standard under STF 378. Simulation results for the investigation of characteristics of nl4 DQPSK performance below 200 MHz have also been also presented to ETSI TETRA as a contribution to the existing TEDS standard. The Results presented for the design of IPv6 enabled stacked with integrated RoHC have been submitted as deliverable under the FP-7 project DLC+VIT4IP. All the results, simulations and investigations presented in the thesis have been carried out through the platform provided by HW Communication Ltd.

APA, Harvard, Vancouver, ISO, and other styles

23

Anbiyaei, Mohammad Reza. "White noise reduction for wideband sensor array signal processing." Thesis, University of Sheffield, 2018. http://etheses.whiterose.ac.uk/19893/.

Full text

Abstract:

The performance of wideband array signal processing algorithms is dependant on the noise level in the system. In this thesis, a method is proposed for reducing the level of white noise in wideband arrays via a judiciously designed spatial transformation followed by a bank of high-pass filters. The method is initially introduced for uniform linear arrays (ULAs) and analysed in detail. The spectrum of the signal and noise after being processed by the proposed noise reduction method is analysed, and the correlation matrix of the processed noise is derived. The reduced noise level leads to a higher signal-to-noise ratio (SNR) for the system, which can have a significant effect on the performance improvement of various beamforming methods and other array signal processing applications such as direction of arrival (DOA) estimation. The performance of two well-known beamformers, the reference signal based (RSB) beamformer and the linearly constrained minimum variance (LCMV) beamformer is reviewed. Then, the theoretical effect of applying the proposed noise reduction method as a pre-processing step on the performance enhancement of RSB and LCMV beamformers is studied. The theoretical results are then confirmed by simulation. As a representative example of wideband DOA estimation application, a compressive sensing-based DOA estimation method is employed to demonstrate the improved estimation by applying the pre-processing noise reduction method, which is confirmed by simulation. Next, the idea is extended to wideband non-uniform linear arrays (NLAs). Since, NLA does not have a uniform spacing, the beam response of the row vectors of the transformation is distorted. Therefore, the transformation is re-designed using the least squares method to satisfy the band-pass requirements of the transformation. Simulation results show a satisfactory improvement in the the performance of RSB and LCMV beamformers for the NLA structure. The idea is further extended to uniform rectangular arrays (URAs) and uniform circular arrays (UCAs), as two major types of the planar arrays. Two methods are proposed for reducing the effect of white noise in wideband URAs and for each one, a different transformation is designed. The first one is based on a two-dimensional (2D) transformation and the second one is an adaptation of the method developed for the ULA case. The developed method for the UCA structure is based on a one-dimensional (1D) transformation, with modified modulation for the transformation to satisfy the required band-pass characteristics of the transformation. Same as linear array structures, the RSB and LCMV beamformers are used to demonstrate the performance enhancement of the method for planar arrays.

APA, Harvard, Vancouver, ISO, and other styles

24

Lam, Vicky Yin Hay. "Audio signal compression and modelling using psychoacoustic excitation pattern and loudness models." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248501.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Jeong, Soonho. "Wideband signal analysis and synthesis applied to electromagnetic transient waveforms." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA308099.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Ng, William Reilly James P. "Advances in wideband array signal processing using numerical Bayesian methods /." *McMaster only, 2003.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

27

Yoon, Yeo-Sun. "Direction-of-arrival Estimation of Wideband Sources Using Sensor Arrays." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5110.

Full text

Abstract:

Sensor arrays are used in many applications where their ability to localize signal sources is essential. For many applications, it is necessary to estimate the direction-of-arrival (DOA) of target sources. Although there are many DOA estimation methods available, most of them are valid only for narrowband signals where time delay can be approximated as a phase shift. This thesis focuses on DOA estimation algorithms for wideband sources. Specifically, this thesis proposes the pruned fast beamformer which can reduce the number of computations of Delay-and-Sum (DS) beamforming by using a multi-resolution structure. For high resolution methods, signal subspace methods are required. Most of the subspace techniques for wideband signals decompose the received wideband signals into several bands of narrowband signals through bandpass filtering. Then, there are two different ways of processing decomposed signals. The incoherent methods process each band independently by a given narrowband method and average the results. The coherent methods attempt to modulate the signals in each band so that they can be combined coherently. In this thesis, a new DOA estimator, which is called TOPS, is developed to avoid disadvantages of both the incoherent and the coherent methods. The new method which can be categorized as a non-coherent method is tested and compared with other methods. It exhibits many desirable features for a number of applications where the sources are wideband such as acoustic direction finding.

APA, Harvard, Vancouver, ISO, and other styles

28

Park, Shinwoong. "Reconfigurable Discrete-time Analog FIR filters for Wideband Analog Signal Processing." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/99794.

Full text

Abstract:

Demand for data communication capacity is rapidly increasing with more and more number of users and higher bandwidth services. As a result, a critical research issue is the implementation of wideband and flexible signal processing in communication and sensing applications. Although software defined radio (SDR) is a possible solution, it may not be practical due to the excessive requirements for analog-to-digital converter (ADCs) and digital filters for wideband signals. In this environment, discrete-time (DT) domain circuits are gaining attention in various architectures such as N-path filters, sampling mixers, and analog FIR/IIR/FFT filters. DT analog signal processing (DT-ASP) ahead of an ADC considerably relaxes the ADC requirements by flexible filtering, offers the potential for higher dynamic range performance, and provides robustness in the presence of digital CMOS scaling. The primary work presented in this dissertation is the design of wideband analog finite impulse response (AFIR) filters. Analog FIR filters have been used as low pass filters for out-of-band rejection in narrow-band applications. However, this work seeks to develop AFIR filters suitable for wideband applications, extending its possible applications. To achieve these performance goals, capacitive digital to analog converters (CDACs) have been introduced for the first time as wideband analog coefficient multipliers, which has led to high linearity analog multiplication with coefficient selection at the DAC resolution. A prototype 4th order DT FIR filter has been implemented in 32nm SOI CMOS technology and has achieved low-pass, band-pass, and high-pass filter (LPF, BPF and HPF) transfer functions corresponding to the programmed coefficient sets with IIP3>11dBm linearity and less than 2 mW/tap of power consumption. The AFIR filter is also utilized to demonstrate a proof-of-concept FIR-based beamforming. The beamforming network consisting of 4 antenna element inputs followed by AFIR filters was implemented with PCB modules with the previously fabricated AFIR filter chip. Behavioral simulations are used to verify the beamforming function with given coefficient sets. Based on the developed AFIR filter modules, FIR-based beamforming was demonstrated with measurement results matching well with the simulations. Further work presented is the design and optimization of multi-section CDAC (MS-CDAC) structures. The proposed MS-CDAC approach provides wide range of options to optimize the tradeoff between kT/C noise, linearity versus switching energy, speed and area. When the optimization approach is applied to a proof-of-concept 10-bit CDAC design, the selected MS-CDAC structure reduces total capacitance and switching energy by 97% and 98%, respectively for given linearity and noise limitations. The proposed MS-CDAC structures are applicable in both DT-ASP coefficient multiplier and SAR-ADC applications.
PHD

APA, Harvard, Vancouver, ISO, and other styles

29

Rau, Richard. "Postprocessing tools for ultra-wideband SAR images." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/13389.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Chu, Xiaoli. "Ultra-wideband direct-sequence impulse radio wireless communications /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20CHU.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Yajnanarayana, Vijaya Parampalli. "Ultra Wideband: Communication and Localization." Doctoral thesis, KTH, Signalbehandling, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-197320.

Full text

Abstract:

The first part of this thesis develops methods for UWB communication. To meet the stringent regulatory body constraints, the physical layer signaling technique of the UWB transceiver should be optimally designed. We propose two signaling schemes which are variants of pulse position modulation (PPM) signaling for impulse radio (IR) UWB communication. We also discuss the detectors for the signaling schemes and evaluate the performance of these detectors. IR-UWB can be used for precise range measurements as it provides a very high time resolution. This enables accurate time of arrival (TOA) estimations from which precise range values can be derived. We propose methods which use range information to arrive at optimal schedules for an all-to-all broadcast problem. Results indicate that throughput can be increased on average by three to ten times for typical network configurations compared to the traditional methods. Next, we discuss hypothesis testing in the context of UWB transceivers. We show that, when multiple detector outputs from a hardware platform are available, fusing the results from them can yield better performance in hypothesis testing than relying on a single detector output. In the second part of this thesis, the emphasis is placed on localization and joint estimation of location and communication parameters. Here, we focus on estimating the TOA of the signal. The wide bandwidth of the UWB signal requires high speed analog to digital converts (ADC) which makes the cost of the digital transceivers prohibitively high. To address this problem, we take two different strategies. In the first approach, we propose a multichannel receiver with each channel having a low-cost energy detector operating at a sub-Nyquist rate. In the second approach, we consider a compressive sampling based technique. Here, we propose a new acquisition front end, using which the sampling rate of the ADC can be significantly reduced. We extended the idea of compressive sampling based TOA estimation towards joint estimation of TOA and PPM symbols. Here, two signaling methods along with the algorithms are proposed based on the dynamicity of the target. They provide similar performance to the ML based estimation, however with a significant savings in the ADC resources.

QC 20161205

APA, Harvard, Vancouver, ISO, and other styles

32

Shaik, Majid. "Direction of Arrival Estimation using Wideband Spectral Subspace Projection." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1453219825.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Brooks, William Allen. "Ultra-wideband radar transient signal detection using time-frequency and wavelet transforms." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School; Available from the National Technical Information Service, 1992. http://edocs.nps.edu/npspubs/scholarly/theses/1992/Dec/92Dec_Brooks.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Jiang, Hao Burdick Joel Wakeman Burdick Joel Wakeman. "Adaptive feature selection in pattern recognition and ultra-wideband radar signal analysis /." Diss., Pasadena, Calif. : California Institute of Technology, 2008. http://resolver.caltech.edu/CaltechETD:etd-05302008-134607.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Lehne, Mark. "An Analog/Mixed Signal FFT Processor for Ultra-Wideband OFDM Wireless Transceivers." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/28819.

Full text

Abstract:

As Orthogonal Frequency Division Multiplexing (OFDM) becomes more prevalent in new leading-edge data rate systems processing spectral bandwidths beyond 1 GHz, the required operating speed of the baseband signal processing, specifically the Analog- to-Digital Converter (ADC) and Fast Fourier Transform (FFT) processor, presents significant circuit design challenges and consumes considerable power. Additionally, since Ultra-WideBand (UWB) systems operate in an increasingly crowded wireless environment at low power levels, the ability to tolerate large blocking signals is critical. The goals of this work are to reduce the disproportionately high power consumption found in UWB OFDM receivers while increasing the receiver linearity to better handle blockers. To achieve these goals, an alternate receiver architecture utilizing a new FFT processor is proposed. The new architecture reduces the volume of information passed through the ADC by moving the FFT processor from the digital signal processing (DSP) domain to the discrete time signal processing domain. Doing so offers a reduction in the required ADC bit resolution and increases the overall dynamic range of the UWB OFDM receiver. To explore design trade-offs for the new discrete time (DT) FFT processor, system simulations based on behavioral models of the key functions required for the processor are presented. A new behavioral model of the linear transconductor is introduced to better capture non-idealities and mismatches. The non-idealities of the linear transconductor, the largest contributor of distortion in the processor, are individually varied to determine their sensitivity upon the overall dynamic range of the DT FFT processor. Using these behavioral models, the proposed architecture is validated and guidelines for the circuit design of individual signal processing functions are presented. These results indicate that the DT FFT does not require a high degree of linearity from the linear transconductors or other signal processing functions used in its design. Based on the results of the system simulations, a prototype 8-point DT FFT processor is designed in 130 nm CMOS. The circuit design and layout of each of the circuit functions; serial-to-parallel converter, FFT signal flow graph, and clock generation circuitry is presented. Subsequently, measured results from the first proof-of-concept IC are presented. The measured results show that the architecture performs the FFT required for OFDM demodulation with increased linearity, dynamic range and blocker handling capability while simultaneously reducing overall receiver power consumption. The results demonstrate a dynamic range of 49 dB versus 36 dB for the equivalent all-digital signal processing approach. This improvement in dynamic range increases receiver performance by allowing detection of weak sub-channels attenuated by multipath. The measurements also demonstrate that the processor rejects large narrow-band blockers, while maintaining greater than 40 dB of dynamic range. The processor enables a 10x reduction in power consumption compared to the equivalent all digital processor, as it consumes only 25 mWatts and reduces the required ADC bit depth by four bits, enabling application in hand-held devices. Following the success of the first proof-of-concept IC, a second prototype is designed to incorporate additional functionality and further demonstrate the concept. The second proof-of-concept contains an improved version of the serial-to-parallel converter and clock generation circuitry with the additional function of an equalizer and parallel- to-serial converter. Based on the success of system level behavioral simulations, and improved power consumption and dynamic range measurements from the proof-of-concept IC, this work represents a contribution in the architectural development and circuit design of UWB OFDM receivers. Furthermore, because this work demonstrates the feasibility of discrete time signal processing techniques at 1 GSps, it serves as a foundation that can be used for reducing power consumption and improving performance in a variety of future RF/mixed-signal systems.
Ph. D.

APA, Harvard, Vancouver, ISO, and other styles

36

Chaturvedi, Amal. "Wideband Signal Delay and Direction of Arrival Estimation using sub-Nyquist Sampling." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1416231079.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Matsuo, A. T., and E. L. Law. "SIGNAL TRANSMISSION FROM REMOTE TELEMETRY ANTENNAS USING WIDEBAND ANALOG FIBER OPTIC LINKS." International Foundation for Telemetering, 1991. http://hdl.handle.net/10150/612160.

Full text

Abstract:

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada
This paper will present the results of an investigation of the feasibility of using broadband analog fiber optic technology to send telemetry antenna outputs from remote sites to a central site. The fiber optic hardware consisted of a prototype analog fiber optic transmitter and receiver plus 10 km of single-mode fiber. Laboratory tests were performed to simulate the performance in the real-world. The fiber optic system had a noise figure of 33.5 dB and a third order intercept point of 16.75 dBm. The use of this fiber optic system to transmit a 215-320 MHZ telemetry antenna downconverter output over a 10 km fiber would only degrade the quality of real-world telemetry signals by a few tenths of a decibel. Key words: analog fiber optic transmission, remote telemetry antennas.

APA, Harvard, Vancouver, ISO, and other styles

38

Tsou, Thomas. "Implementation of Wideband Multicarrier and Embedded GSM." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/35181.

Full text

Abstract:

The Global System for Mobile (GSM) cellular standard, having been in existence for over two decades, is the most widely deployed wireless technology in the world. While third generation networks and beyond, such as Universal Mobile Telecommunications System (UMTS) and Long Term Evolution (LTE), are undergoing extraordinary growth and driving a large share of current cellular development, technologies and deployments based on GSM are still dominant on a global scale and, like more recent standards, continue to evolve very rapidly.

The software-defined radio (SDR) base station is one technology that is driving rapid change in cellular infrastructure. While commercial vendors have now embraced SDR, there is another movement that has recently gained prominence. That movement is the convergence of open source software and hardware with cellular implementation. OpenBTS, a deployable implementation of the GSM radio air interface, and the Universal Software Radio Peripheral (USRP), a RF hardware platform, are two primary examples of such open source software and hardware products. OpenBTS and the USRP underlie three GSM features that are implemented and presented in this thesis.

This thesis describes the extension of the OpenBTS software-defined radio transceiver in the three critical areas of user capacity, transmit signal integrity, and the embedded small form factor. First, an optimized wideband multicarrier implementation is presented that substantially increases the capacity beyond that of a single carrier system. Second, the GSM modulator is examined in depth and extended to provide performance that exceeds standards compliance by a significant margin. Third, operation of the GSM transceiver on an E100 embedded platform with ARM and fixed point DSP processors will be explored, optimized, and tested.

Master of Science

APA, Harvard, Vancouver, ISO, and other styles

39

Gu, Jing. "High IIP3 up-conversion mixer for ultra-wideband (UWB) application /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20GU.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Eisenacher, Michael [Verfasser]. "Optimierung von Ultra-Wideband-Signalen (UWB) / von Michael Eisenacher, geb. Schmidt." Karlsruhe : Inst. für Nachrichtentechnik, 2006. http://d-nb.info/1003466907/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Srinivasan, Shivratna Giri. "Signal constellations via optimization of information theoretic metrics for MIMO wideband fading channels." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3284425.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Agjee, F. M. D. E. (Faatima Moosa Dawood Ebrahim). "A wideband signal conditioning system for high voltage measurements using a transconductance topology." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51633.

Full text

Abstract:

Thesis (MScEng)--Stellenbosch University, 2000.
ENGLISH ABSTRACT: Recent research has shown that standard substation capacitive voltage transformers (CVTs) and current transformers (CTs) can be used for the measurement of wideband high voltage phenomena by employing these apparatus in a transconductance topology. With this topology the voltage waveform can be obtained by integration of the ground return current in the earth straps of the CVT and the CT. This technique does, however, impose unique requirements on the amplification and integration instrumentation due to large dynamic range requirements and the strict offset specifications required for accurate integration. This thesis describes a programmable, wideband signal conditioning system for high voltage (HV) measurements using the transconductance topology. A suitable system topology, optimised to reduce the problems usually associated with grounding and electromagnetic interference (EMI) in HV environments, is proposed. This system consists of an analog signal conditioning subsystem, a digital signal conditioning subsystem and a high speed serial fibre-optic link. The analog signal conditioning subsystem conditions the signals from a sensor to levels suitable for the digitiser of the digital signal conditioning subsystem. The high bandwidth specification of the application made it necessary to consider both discrete and integrated implementation of the analog signal conditioning subsystem. Based on the simulated and laboratory test results of both implementations, the optimum design was chosen for the developed system. The digital signal conditioning subsystem, which performs the integration, as well as the serial optic-fibre link control logic was implemented using programmable logic array (PLA) technology. The digital data is transmitted across the fibre-optic link. This data is then converted back to an analog signal. Keywords: High voltage measurements, Transconductance topology.
AFRIKAANSE OPSOMMING: Onlangse navorsing het aangetoon dat standaard substasie kapasitiewe spanningstransformators en stroomtransformators gebruik kan word om wyeband hoogspanningsverskynsels te meet deur hierdie apparatuur in 'n transkonduktansie topologie aan te wend. Met hierdie topologie kan die spanningsgolfvorm verkry word deur die integrasie van die aardstrome in die aardverbindings van die kapasitiewe spanningstransformators en stroomtransformators. Hierdie tegniek stel egter unieke vereistes vir die versterkings- en integrasieinstrumentasie te wyte aan groot dinamiese bereik vereistes en die streng afset spesifikasies wat benodig word vir akkurate integrasie. Hierdie tesis beskryf 'n programmeerbare, wyeband seinkondisioneringstelsel vir hoogspanningsmetings deur van die transkonduktansie topologie gebruik te maak. 'n Geskikte stelseltopologie, wat geoptimiseer is om probleme, wat gewoonlik met aarding en elektromagnetiese interferensie in hoogspanningsomgewings geassosieer word, te verminder, is voorgestel. Die stelsel bestaan uit 'n analoog seinkondisioneringsubstelsel, 'n digitale seinkondisioneringsubstelsel en 'n hoëspoed seriële optiese vesel koppelvlak. Die analoog seinkondisioneringsubstelsel kondisioneer die seine vanaf 'n sensor na geskikte vlakke vir die versyferaar van die digitale seinkondisioneringsubstelsel. Die hoë bandwydte spesifikasie van die toepassing vereis die inagneming van beide diskrete en geïntegreerde implementerings van die analoog seinkondisioneringsubstelsel. Gebaseer op gesimuleerde en laboratorium toetsresultate van beide implementerings is die optimale ontwerp vir die ontwikkelde stelsel gekies. Die digitale seinkondisioneringsubstelsel wat die integrasie uitvoer, asook die seriële optiese vesel koppelvlak beheerlogika is geïmplementeer met behulp van programmeerbare logika skikking tegnologie. Die digitale data word gestuur oor die optiese vesel koppelvlak. Hierdie data word dan terug geskakel na 'n analoog sein. Sleutelwoorde: Hoogspanningsmetings, Transkonduktansie topologie.

APA, Harvard, Vancouver, ISO, and other styles

43

Stephan, Antoine. "Resource Allocation Strategies and Linear Precoded OFDM Optimization for Ultra-Wideband Communications." Phd thesis, INSA de Rennes, 2008. http://tel.archives-ouvertes.fr/tel-00376632.

Full text

Abstract:

L'ultra large bande (UWB) est une nouvelle technologie à fort potentiel pour les futurs réseaux personnels WPAN (wireless personal area networks) à très haut débit et faible portée. L'objectif de cette thèse est de proposer un nouveau système UWB, de type LP-OFDM (linear precoded orthogonal frequency division multiplexing) pour les applications WPAN, visant à améliorer la solution MB-OFDM (multiband OFDM), supportée par l'Alliance WiMedia.
Dans un premier temps, une étude analytique est menée sur l'apport de la composante de précodage au système UWB, cette composante se réduisant en pratique à une simple addition d'une matrice d'étalement fréquentiel. La fonction de précodage est ensuite optimisée et différentes stratégies d'allocation dynamique des ressources sont étudiées. En considérant une approche classique tenant compte du taux d'erreur symbole (TES) ainsi qu'une nouvelle approche tenant compte du taux d'erreur binaire (TEB) moyen, différents algorithmes d'allocation dynamique visant à maximiser la portée ou le débit du système, ou à minimiser le TEB moyen du système, sont proposés. Les résultats analytiques montrent l'avantage d'utiliser une composante de précodage pour les applications UWB dont le canal est très sélectif en fréquence.
Dans un second temps, une étude système complémentaire à l'étude analytique est réalisée pour le système LP-OFDM UWB. Une composante MIMO est ajoutée au système, d'une part pour augmenter la portée du système à bas et moyen débit, et d'autre part pour augmenter le débit du système qui peut atteindre dans ce cas 1 gigabit/s. Les résultats de simulation sur le système proposé montrent que ce système est plus performant que le système MB-OFDM pour les débits déjà proposés dans la norme, et qu'il offre un débit deux fois plus important que ceux de la norme avec même une meilleure performance en terme de TEB.

APA, Harvard, Vancouver, ISO, and other styles

44

Al, irkhis Luay A. "Wideband DoA and Parameter Estimation of Chirp Sources using DCFT and Compressive Sensing." Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright1547548984021509.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Sarathy, Vivek. "High Spurious-Free Dynamic Range Digital Wideband Receiver for Multiple Signal Detection and Tracking." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1197910677.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Bayram, Ahmet. "A Study of Indoor Ultra-wideband Propagation Measurement and Characterization." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/32748.

Full text

Abstract:

Ultra-wideband (UWB) communication is emerging as a new wireless technology, which promises high data rates with low interference and low power consumption. The development of such UWB systems requires a sufficiently large amount of data to characterize the propagation behavior of UWB signals in indoor environments and develop accurate channel models. This thesis focuses primarily on a frequency-domain approach for propagation measurements and characterization of indoor UWB channels. This approach is based on measurements of the amplitude using a scalar network analyzer and retrieval of the phase from the amplitude data using a Hilbert transform relationship.

Extensive propagation data are collected in a frequency range of 1 to 12 GHz in two buildings on Virginia Tech campus. Using the data, channel characterization results are obtained and compared to those based on time-domain measurements. Some statistical results for small-scale fading, path loss exponent, and signal quality are presented. This comparison validates the accuracy of measured results for the UWB measurement campaign. The measured data also reaffirms the immunity of UWB propagation to small-scale fading which is present in narrowband wireless communication systems.

In addition to channel propagation measurements, signal distortions in UWB links, due to bandwidth limitations of antenna characteristics as well as the dispersive behavior of building materials, are also examined. In particular, the distortion of radiated signals by TEM horn antennas along off-boresight directions are studied experimentally. Furthermore, pulse distortions resulting from propagation through dispersive walls are demonstrated by simulation. The roles of receive-transmit antennas in a UWB link are examined, and the requirements for gain, input impedance, polarization, and phase of the radiated signal necessary for minimization of signal distortions are pointed out.
Master of Science

APA, Harvard, Vancouver, ISO, and other styles

47

Wang, Zhongmin. "New sampling and detection approaches for compressed sensing and their application to ultra wideband communications." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 125 p, 2010. http://proquest.umi.com/pqdweb?did=1997524101&sid=6&Fmt=2&clientId=8331&RQT=309&VName=PQD.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Beukman, Theunis Steyn. "Tune-all wideband planar filters for KAT-7." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/17791.

Full text

Abstract:

Thesis (MScEng)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: A new type of wideband lters, with tunability in both the centre frequency and bandwidth, is presented in this thesis. These lters are based on perturbed ring-resonators in cascade, while varactor diodes are used for electronic tuning. The Karoo Array Telescope (KAT-7) requires a front-end lter that has the ability for ne-tuning the response after fabrication, in order to obtain the designed ltering response. Not only are tune-all characteristics required, but also wide bandwidth, at passband, high selectivity and implementation in microstrip technology. In this thesis an extensive investigation of both tunable and wideband lters is done, in order to nd a possible solution for the KAT-7 speci cations. Following this investigation, it is concluded that no suitable design approach for tune-all wideband lters, implemented in microstrip, exists in current literature. Therefore, this thesis proposes a new type of lter along with the development of a complete design procedure. Two lters are designed with this procedure to achieve the required passband from 1.2 to 1.95 GHz (i.e. a fractional bandwidth of 49%). In the rst lter design, with a network consisting of 4 cascaded ltering-sections, the centre frequency is 5% tunable and the bandwidth 17.5%. With the second lter consisting of 6 cascaded ltering-sections, higher selectivity is achieved but with lower return loss. Here the centre frequency is 8.5% tunable and the bandwidth 18.8%. The theoretical results are validated with the fabrication of both lters. This design is very unique in that it achieves wide bandwidth, is realisable in microstrip and most importantly is tunable in both the centre frequency and bandwidth. An advantage of this design procedure is that full wave simulations are minimal, due to the complete circuit models used for optimisation.
AFRIKAANSE OPSOMMING: 'n Nuwe soort van wye-band lters, met verstelbaarheid in beide senter frekwensie en bandwydte, word voorgelê in hierdie tesis. Hierdie lters is gebaseer op versteurde ringresoneerders in kaskade, terwyl varaktordiodes gebruik word vir elektroniese verstelling. Die Karoo Array Telescope (KAT-7) vereis 'n voorkant lter wat die vermoë het vir die instemming van die respons na fabrikasie, sodat die geontwerpde lter respons behaal kan word. Nie net word verstel-als eienskappe vereis nie, maar ook wye bandwydte, plat deurlaatband, hoë selektiwiteit en implimentering in mikrostrook tegnologie. In hierdie tesis is 'n veelomvattende ondersoek gedoen van beide verstelbare en wyeband lters, sodat 'n moontlike oplossing vir die KAT-7 spesi kasies gevind kan word. Na aanleiding van hierdie ondersoek, is die gevolgtrekking dat daar geen gepaste ontwerp benadering vir verstel-als wye-band lters, wat geïmplimenteer is in mikrostrook, in huidige literatuur bestaan nie. Daarom stel hierdie tesis, saam met die ontwikkeling van 'n volledige ontwerp prosedure, 'n nuwe tipe lter voor. Twee lters is ontwerp met hierdie prosedure om die vereiste deurlaatband vanaf 1.2 tot 1.95 GHz (dit is 'n fraksionele bandwydte van 49%) te behaal. In die eerste lter ontwerp, met 'n netwerk wat uit 4 kaskade lter-seksies bestaan, is die senter frekwensie 5% verstelbaar en die bandwydte 17.5%. Met die tweede lter bestaande uit 6 kaskade lter-seksies, word hoër selektiwiteit behaal maar met laer eggoverswakking. Hier is die senter frekwensie 8.5% verstelbaar en die bandwydte 18.8%. Die teoretiese resultate is geldig bewys deur die fabrikasie van albei lters. Hierdie ontwerp is baie uniek in dat dit wye bandwydte behaal, is realiseerbaar in mikrostrook en mees belangrikste dat dit verstelbaar is in beide senter frekwensie en bandwydte. 'n Voordeel van hierdie prosedure is dat heelgolf simulasies minimaal is, a.g.v. die volledige stroombaan modelle wat gebruik word vir optimering.

APA, Harvard, Vancouver, ISO, and other styles

49

George, Kiranraj. "Design and Performance Evaluation of 1 Giga Hertz Wideband Digital Receiver." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1183662240.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Briles, Scott D. "A numerical procedure for computing probability of detection for a wideband pulse receiver." Thesis, Kansas State University, 1986. http://hdl.handle.net/2097/9902.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Wideband signals'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles