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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

DIGITAL IMPLEMENTATION OF A BPSK DEMODULATOR

Meier, Robert C. 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / Some Telemetry systems today receive a binary phase shift keying modulation format. Typically, to demodulate BPSK requires using a carrier synchronizer followed by a bit synchronizer. Demodulation of BPSK can be accomplished using digital signal processing techniques to implement both synchronizers. This paper describes a digital system that demodulates a 16 KHZ, 2KBPS BPSK signal. In order to evaluate these techniques, the theory of operation was evaluated. Additionally, a computer simulation of the demodulator was developed. The computer simulation was implemented using Pascal. The techniques were optimized to give maximum performance while requiring minimum hardware and power in an actual implementation.
2

Full digital BPSK demodulator with supressed carrier for satellite telecommand channel applications / Demodulador BPSK completamente digital com portadora suprimida para telecomando de satÃlites

Caio Gomes de Figueredo 09 June 2015 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / This work presents a new structure for an all-digital BPSK demodulator developed for space communications that performs simultaneously the sampling and down-conversion of the the intermediate frequency signal to the baseband signal. The most important aspect of this work is the design of a new interpolator to retrieve lost samples during the down conversion process, and also to simplify the demodulator implementation. This interpolator correlates the samples of the output signal in such way that it was necessary to design a optimum filter appropriate to process the samples corrupted by gaussian and colored noise. The effects of the new interpolation at the noise are analyzed as well as the way it affects the whole demodulator performance. After performing the optimum filtering, the phase and symbol offsets are estimated and corrected. For the phase, for example, it was used a DPLL (Digital Phase Locked Loop), a digital variation of the PLL, a well known structure and largely utilized in analogical electronics. The DPLL is a closed-loop structure that estimates and corrects the values for the angular which corresponds to the phase deviation caused by the offset between the transmitter and receiver oscilators. For the timing parameter estimation, it was used the Oerder&Meyer estimator that is the digital equivalent to the well known square timing recovery structure. After that, the correction is performed by an interpolation operation over the samples of the received signal, where a filter, named Farrow filter, is applied to these samples, calculating the new samples of that signal at the corrected time instants. This system is mathematically described, all the signals expressions of every stage of the demodulator are analyzed, including the noise statistics. Some computational simulation results are shown and the performance degradation is discussed. / Este trabalho apresenta um modelo de demodulador que realiza simultaneamente a conversÃo analÃgico-digital e a conversÃo em frequÃncia por amostragem em banda passante de um sinal com modulaÃÃo BPSK (Binary Phase Shift Keying) para aplicaÃÃo em enlaces espaciais. O aspecto mais importante do trabalho foi o desenvolvimento de uma nova operaÃÃo de interpolaÃÃo para recuperaÃÃo das amostras perdidas na conversÃo de frequÃncia e que simplifica a implementaÃÃo do demodulador. O interpolador correlaciona as amostras do sinal de forma que torna-se necessÃrio o projeto de um filtro Ãtimo apropriado para processar as amostras corrompidas e mitigar os efeitos do ruÃdo gaussiano e colorido. Os efeitos deste novo interpolador no ruÃdo sÃo analisados, assim como a forma em que ele afeta a performance do sistema. ApÃs a filtragem Ãtima, segue a correÃÃo dos erros de sincronismo de atraso de simbolo e de fase. Para a recuperaÃÃo do sincronismo de fase foi utilizado um DPLL (Digital Phase Locked Loop), uma variante digital de uma estrutura bastante conhecida e utilizada em eletrÃnica analÃgica. O DPLL à uma estrutura em malha fechada que estima e corrige os valores do desvio angular das amostras, o que corresponde ao devio provocado pela diferenÃa de fase entre os osciladores do transmissor e do receptor. Para a recuperaÃÃo do atraso de sÃmbolo foi utilizada, para estimaÃÃo do tempo de atraso, o estimador de Oerder&Meyer que à o equivalente digital da conhecida recuperaÃÃo de temporizaÃÃo em tempo contÃnuo com a lei quadrÃtica. ApÃs a estimaÃÃo ser realizada, à feita a correÃÃo deste atraso nas amostras do sinal recebido atravÃs de uma operaÃÃo de interpolaÃÃo, onde novos valores do sinal sÃo calculados para os instantes de tempo corrigidos. Essa operaÃÃo à realizada por um filtro interpolador, uma estrutura especial conhecida como estrutura de Farrow. O sistema proposto foi descrito matematicamente, sendo analisadas as expressÃes dos sinais nos diferentes estÃgios do conversor, bem como as estatÃsticas dos sinais de ruÃdo. Apresentam-se os resultados da simulaÃÃo computacional nos quais se avalia a perda no desempenho do demodulador, analisando suas causas.
3

Pseudonáhodné posloupnosti v UWB systémech / Pseudo-random sequencies in UWB systems

Laška, Richard January 2008 (has links)
This master´s thesis deals with Ultra-wideband and reveals present stage of this technology and situation on marketplace. In this work I will mention the milestones of its history and describe main fundamentals of communication and modulation methods in UWB systems. This work provides an overview of methods in pseudo-noise code design. The practical part includes UWB system simulation based on BPSK modulation and Directsequence multi-access scenario. This work presents BPSK modulated signal behavior in UWB channel model, where AWGN noise and multi-path energy is taken into account. Only physical layer was tested. At the end of this thesis, the summary and conclusion simulation results will be discussed. Bit error rate characteristic is a product of this testing.
4

Komunikační systém s rozprostřeným spektrem / Spread-spectrum Communication System

Machala, Pavel January 2012 (has links)
The thesis focuses on issues around communication system with the Direct Spread Spectrum Signal Signal. This work outlines the theoretical analysis of this technique and subsequently is created a communication system concept. The device concept is adjusted so that the device can be used as a laboratory device, presenting the spreading technique. This thesis offers a comprehensive and detailed description of the communication system construction, including design of transmitter, receiver and a common transmission channel. In conclusion are stated the results of devised communication system.
5

Analysis and Design of a Sub-THz Ultra-Wideband Phased-Array Transmitter

Steinweg, Luca 31 July 2023 (has links)
This thesis investigates circuits and systems for broadband high datarate transmitter systems in the millimeter-wave (mm-wave) spectrum. During the course of this dissertation, the design process and characterization of a power efficient and wideband binary phase-shift keying (BPSK) transmitter integrated circuit (IC) with local oscillator (LO) frequency multiplication and 360° phase control for beam steering is studied. All required circuit blocks are designed based on the theoretical analysis of the underlying principles, optimized, fabricated and characterized in the research laboratory targeting low power consumption, high efficiency and broadband operation. The phase-controlled push-push (PCPP) architecture enabling frequency multiplication by four in a single stage is analytically studied and characterized finding an optimum between output power and second harmonic suppression depending on the input amplitude. A PCPP based LO chain is designed. A circuit is fabricated establishing the feasibility of this architecture for operation at more than 200 GHz. Building on this, a second circuit is designed, which produces among the highest saturated output powers at 2 dBm. At less than 100 mW of direct current (DC) power consumption, this results in a power-added efficiency (PAE) of 1.6 % improving the state of the art by almost 30 %. Phase-delayed and time-delayed approaches to beam steering are analyzed, identifying and discussing design challenges like area consumption, signal attenuation and beam squint. A 60 GHz active vector-sum phase-shifter with high gain of 11.3 dB and output power of 5 dBm, improving the PAE of the state of the art by a factor of 30 achieving 6.29 %, is designed. The high gain is possible due to an optimization of the orthogonal signal creation stage enabled by studying and comparing different architectures leading to a trade off of lower signal attenuation for higher area consumption in the chosen electromagnetic coupler. By combining this with a frequency quadrupler, a phase steering enabled LO chain for operation at 220 GHz is created and characterized, confirming the preceding analysis of the phase-frequency relation during multiplication. It achieves a power gain of 21 dB, outperforming comparable designs by 25 dB. This allows the combination of phase control, frequency multiplication and pre-amplification. The radio frequency (RF) efficiency is increased 40-fold to 0.99 %, with a total power consumption of 105 mW. Motivated by the distorting effect of beam squint in phase-delayed broadband array systems, a novel analog hybrid beam steering architecture is devised, combining phase-delayed and time-delayed steering with the goal of reducing the beam squint of phase-delayed systems and large area consumption of time-delayed circuits. An analytical design procedure is presented leading to the research finding of a beam squint reduction potential of more than 83 % in an ideal system. Here, the increase in area consumption is outweighed by the reduction in beam squint. An IC with a low power consumption of 4.3 mW has been fabricated and characterized featuring the first time delay circuit operating at above 200 GHz. By producing most of the beam direction by means of time delay the beam squinting can be reduced by more than 75 % in measurements while the subsequent phase shifter ensures continuous beam direction control. Together, the required silicon area can be reduced to 43 % compared to timedelayed systems in the same frequency range. Based on studies of the optimum signal feeding and input matching of a Gilbert cell, an ultra-wideband, low-power mixer was designed. A bandwidth of more than 100 GHz was achieved exceeding the state of the art by 23 %. With a conversion gain of –13 dB, this enables datarates of more than 100 Gbps in BPSK operation. The findings are consolidated in an integrated transmitter operating around 246 GHz doubling the highest published measured datarates of transmitters with LO chain and power amplifier in BPSK operation to 56 Gbps. The resulting transmitter efficiency of 7.4 pJ/bit improves the state of the art by 70 % and 50 % over BPSK and quadrature phaseshift keying (QPSK) systems, respectively. Together, the results of this work form the basis for low-power and efficient next-generation wireless applications operating at many times the datarates available today.:Abstract 3 Zusammenfassung 5 List of Symbols 11 List of Acronyms 17 Prior Publications 19 1. Introduction 21 1.1. Motivation........................... 21 1.2. Objective of this Thesis ................... 25 1.3. Structure of this Thesis ................... 27 2. Overview of Employed Technologies and Techniques 29 2.1. IntegratedCircuitTechnology................ 29 2.2. Transmission Lines and Passive Structures . . . . . . . . 35 2.3. DigitalModulation ...................... 41 3. Frequency Quadrupler 45 3.1. Theoretical Analysis of Frequency Multiplication Circuits 45 3.2. Phase-Controlled Push-Push Principle for Frequency Quadrupling.......................... 49 3.3. Stand-alone Phase-Controlled Push-Push Quadrupler . 60 3.4. Phase-Controlled Push-Push Quadrupler based LO-chain with High Output Power ............... 72 9 4. Array Systems and Dynamic Beam Steering 91 4.1. Theoretical Analysis of BeamSteering. . . . . . . . . . . 95 4.2. Local Oscillator Phase Shifting with Vector-Modulator PhaseShifters......................... 107 4.3. Hybrid True-Time and Phase-Delayed Beam Steering . 131 5. Ultra-Wide Band Modulator for BPSK Operation 155 6. Broadband BPSK Transmitter System for Datarates up to 56 Gbps 167 6.1. System Architecture ..................... 168 6.2. Measurement Technique and Results . . . . . . . . . . . 171 6.3. Summary and performance comparison . . . . . . . . . 185 7. Conclusion and Outlook 189 A. Appendix 195 Bibliography 199 List of Figures 227 Note of Thanks 239 Curriculum Vitae 241 / Diese Dissertation untersucht Schaltungen und Systeme für breitbandige Transmittersysteme mit hoher Datenrate im Millimeterwellen (mm-wave) Spektrum. Im Rahmen dieser Arbeit werden der Entwurfsprozess und die Charakterisierung eines leistungseffizienten und breitbandigen integrierten Senders basierend auf binärer Phasenumtastung (BPSK) mit Frequenzvervielfachung des Lokaloszillatorsignals und 360°-Phasenkontrolle zur Strahlsteuerung untersucht. Alle erforderlichen Schaltungsblöcke werden auf Grundlage von theoretischen Analysen der zugrundeliegenden Prinzipien entworfen, optimiert, hergestellt und im Forschungslabor charakterisiert, mit den Zielen einer niedrigen Leistungsaufnahme, eines hohen Wirkungsgrades und einer möglichst großen Bandbreite. Die phasengesteuerte Push-Push (PCPP)-Architektur, welche eine Frequenzvervierfachung in einer einzigen Stufe ermöglicht, wird analytisch untersucht und charakterisiert. Dabei wird ein Optimum zwischen Ausgangsleistung und Unterdrückung der zweiten Harmonischen des Eingangssignals in Abhängigkeit von der Eingangsamplitude gefunden. Es wird eine LO-Kette auf PCPP-Basis entworfen. Eine Schaltung wird präsentiert, die die Machbarkeit dieser Architektur für den Betrieb bei mehr als 200 GHz nachweist. Darauf aufbauend wird eine zweite Schaltung entworfen, die mit 2 dBm eine der höchsten publizierten gesättigten Ausgangsleistungen erzeugt. Mit einer Leistungsaufnahme von weniger als 100mW ergibt sich ein Leistungswirkungsgrad (PAE) von 1.6 %, was den Stand der Technik um fast 30 % verbessert. Es werden phasenverzögerte und zeitverzögerte Ansätze zur Steuerung der Strahlrichtung analysiert, wobei Entwicklungsherausforderungen wie Flächenverbrauch, Signaldämpfung und Strahlschielen identifiziert und diskutiert werden. Ein aktiver Vektorsummen-Phasenschieber mit hoher Verstärkung von 11.3 dB und einer Ausgangsleistung von 5 dBm, der mit einer PAE von 6.29 % den Stand der Technik um den Faktor 30 verbessert, wird entworfen. Die hohe Verstärkung ist zum Teil auf eine Optimierung der orthogonalen Signalerzeugungsstufe zurückzuführen, die durch die Untersuchung und den Vergleich verschiedener Architekturen ermöglicht wird. Bei der Entscheidung für einen elektromagnetischen Koppler rechtfertigt die geringere Signaldämpfung einen höheren Flächenverbrauch. Durch die Kombination mit einem Frequenzvervierfacher wird eine LO-Kette mit Phasensteuerung für den Betrieb bei 220 GHz geschaffen und charakterisiert, was die vorangegangene Analyse der Phasen-FrequenzBeziehung während der Multiplikation bestätigt. Sie erreicht einen Leistungsgewinn von 21 dB und übertrifft damit vergleichbare Designs um 25dB. Dies ermöglicht die Kombination von Phasensteuerung, Frequenzvervielfachung und Vorverstärkung. Der HochfrequenzWirkungsgrad wird um das 40-fache auf 0.99 % bei einer Gesamtleistungsaufnahme von 105 mW gesteigert. Motiviert durch den verzerrenden Effekt des Strahlenschielens in phasengesteuerten Breitbandarraysystemen, wird eine neuartige analoge hybride Strahlsteuerungsarchitektur untersucht, die phasenverzögerte und zeitverzögerte Steuerung kombiniert. Damit wird sowohl das Strahlenschielen phasenverzögerter Systeme als auch der große Flächenverbrauch zeitverzögerter Schaltungen reduziert. Es wird ein analytisches Entwurfsverfahren vorgestellt, das zu dem Forschungsergebnis führt, dass in einem idealen System ein Potenzial zur Reduktion des Strahlenschielens von mehr als 83 % besteht. Dabei wird die Zunahme des Flächenverbrauchs durch die Verringerung des Strahlenschielens aufgewogen. Es wird ein IC mit einer geringen Leistungsaufnahme von 4.3mW hergestellt und charakterisiert. Dabei wird die erste Zeitverzögerungsschaltung entworfen, die bei über 200 GHz arbeitet. Durch die Erzeugung eines Großteils der Strahlrichtung mittels Zeitverzögerung kann das Schielen des Strahls bei Messungen um mehr als 75% reduziert werden, während der nachfolgende Phasenschieber eine kontinuierliche Steuerung der Strahlrichtung gewährleistet. Insgesamt kann die benötigte Siliziumfläche im Vergleich zu zeitverzögerten Systemen im gleichen Frequenzbereich auf 43 % reduziert werden. Auf der Grundlage von Studien zur optimalen Signaleinspeisung und Eingangsanpassung einer Gilbert-Zelle wird ein Ultrabreitband-Mischer mit geringem Stromverbrauch entworfen. Dieser erreicht eine Ausgangsbandbreite von mehr als 100 GHz, die den Stand der Technik um 23% übertrifft. Bei einer Wandlungsverstärkung von –13dB ermöglicht dies Datenraten von mehr als 100 Gbps im BPSK-Betrieb. Die Erkenntnisse werden in einem integrierten, breitbandigen Sender konsolidiert, der um 246 GHz arbeitet und die höchsten veröffentlichten gemessenen Datenraten für Sender mit LO-Signalkette und Leistungsverstärker im BPSK-Betrieb auf 56 Gbps verdoppelt. Die daraus resultierende Transmitter-Effizienz von 7.4 pJ/bit verbessert den Stand der Technik um 70 % bzw. 50 % gegenüber BPSKund Quadratur Phasenumtastung (QPSK)-Systemen. Zusammen bilden die Ergebnisse dieser Arbeit die Grundlage für stromsparende, effiziente, mobile Funkanwendungen der nächsten Generation mit einem Vielfachen der heute verfügbaren Datenraten.:Abstract 3 Zusammenfassung 5 List of Symbols 11 List of Acronyms 17 Prior Publications 19 1. Introduction 21 1.1. Motivation........................... 21 1.2. Objective of this Thesis ................... 25 1.3. Structure of this Thesis ................... 27 2. Overview of Employed Technologies and Techniques 29 2.1. IntegratedCircuitTechnology................ 29 2.2. Transmission Lines and Passive Structures . . . . . . . . 35 2.3. DigitalModulation ...................... 41 3. Frequency Quadrupler 45 3.1. Theoretical Analysis of Frequency Multiplication Circuits 45 3.2. Phase-Controlled Push-Push Principle for Frequency Quadrupling.......................... 49 3.3. Stand-alone Phase-Controlled Push-Push Quadrupler . 60 3.4. Phase-Controlled Push-Push Quadrupler based LO-chain with High Output Power ............... 72 9 4. Array Systems and Dynamic Beam Steering 91 4.1. Theoretical Analysis of BeamSteering. . . . . . . . . . . 95 4.2. Local Oscillator Phase Shifting with Vector-Modulator PhaseShifters......................... 107 4.3. Hybrid True-Time and Phase-Delayed Beam Steering . 131 5. Ultra-Wide Band Modulator for BPSK Operation 155 6. Broadband BPSK Transmitter System for Datarates up to 56 Gbps 167 6.1. System Architecture ..................... 168 6.2. Measurement Technique and Results . . . . . . . . . . . 171 6.3. Summary and performance comparison . . . . . . . . . 185 7. Conclusion and Outlook 189 A. Appendix 195 Bibliography 199 List of Figures 227 Note of Thanks 239 Curriculum Vitae 241
6

A UNIQUE "CARD-BASED" FM/PM/BPSK IF RECEIVE FOR SATELLITE DATA RECEPTION

Lam, Daniel-Hung, Moyes, Robert 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / This paper discusses the design and performance of the FM/PM/BPSK "personal computer card-based" receiver. In PSK, a carrier recovery technique must be used for signal demodulation. Costas loop is a well known method and is the basis in the design of the BPSK demodulation. A new design approach employing digital Box Car arm filters is used to improve receiver performance and flexibility. Detail design and performance of the digital Costas loop will be explored in a later section. A classical technique is employed for Phase demodulation with the use of tracking Phase Lock Loop. Frequency demodulation is designed around a simple, single FM discriminator IC.
7

A C-BAND MOBILE TELEMETRY SYSTEM

Wei, Zeng 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / In this paper, it is introduced that a C-Band mobile telemetry system designed for the satellite telemetry task. It can provide a wide range of bit rate and different code type and frame format which is completely set up by user in advance, to meet the requirements needs in different satellites. The PCM-PSK-PM signal and the PPM-MFSK-PM signal can be received and demodulated at the same time. Single channel monopulse technique is employed for automatic tracking. Angle calibration and angle tracking are performed in this system. Real-time data processing, displaying, testing of bit error rate and post-flight analyses is performed by PC type computer. All key components of the system may be programmed.
8

Suppression of impulsive noise in wireless communication

cui, qiaofeng January 2014 (has links)
This report intends to verify the possibility that the FastICA algorithm could be applied to the GPS system to eliminate the impulsive noise from the receiver end. As the impulsive noise is so unpredictable in its pattern and of great energy level to swallow the signal we need, traditional signal selection methods exhibit no much use in dealing with this problem. Blind Source Separation seems to be a good way to solve this, but most of the other BSS algorithms beside FastICA showed more or less degrees of dependency on the pattern of the noise. In this thesis, the basic mathematic modelling of this advanced algorithm, along with the principles of the commonly used fast independent component analysis (fastICA) based on fixed-point algorithm are discussed. To verify that this method is useful under industrial use environment to remove the impulsive noises from digital BPSK modulated signals, an observation signal mixed with additive impulsive noise is generated and separated by fastICA method. And in the last part of the thesis, the fastICA algorithm is applied to the GPS receiver modeled in the SoftGNSS project and verified to be effective in industrial applications. The results have been analyzed. / 6
9

CMA BLIND EQUALIZER FOR AERONAUTICAL TELEMETRY

Xingwen, Ding, Wantao, Zhai, Hongyu, Chang, Ming, Chen 11 1900 (has links)
In aeronautical telemetry, the multipath interference usually causes significant performance degradation. As the bit rate of telemetry systems increases, the impairments of multipath interference are more serious. The constant modulus algorithm (CMA) blind equalizer is effective to mitigate the impairments of multipath interference. The CMA adapts the equalizer coefficients to minimize the deviation of the signal envelope from a constant level. This paper presents the performances of the CMA blind equalizer applied for PCM-FM, PCM-BPSK, SOQPSK-TG and ARTM CPM in aeronautical telemetry.
10

Využití moderních vícetónových modulací v bezdrátových sítích / Application of modern multitone modulations in wireless networks

Hamada, Adam January 2013 (has links)
The main aim of this master's thesis was the create function models of wireless network technologies using the modern multitones modulation like is PFDM and FMT. This work is realised in Matlab – Simulink enviroment and models are tested in development kit. Development kit is universal software defined radio developer by Ettus.

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