Dissertations / Theses: 'Modulation and Demodulation'

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Ozturk, Uygar. "Chaotic Digital Modulation And Demodulation." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606895/index.pdf.

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This thesis considers a communication system with chaotic modulation. Noise-like signals are generated by chaotic systems with different parameters to modulate binary digital signals. Demodulation is performed by both the Extended Kalman Filter (EKF) and Optimum Decoding Based Smoothing Algorithm (ODSA). Simulations are performed using both of these algorithms for different parameters affecting the performance of the communication system. Simulation results of these algorithms are compared.

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Achelengwa, Edison M. "Emona-based interactive amplitude modulation/demodulation iLab." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/66402.

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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 76-78).
The MIT iLab Project has developed online laboratories (iLabs) which are lab stations that can be accessed and controlled remotely over the Internet. With iLabs, students can conduct real experiments on real equipment over the Internet. With the introduction of the National Instrument's Educational Laboratory Virtual Instrument Suite, NI ELVIS, in the development of iLabs, students to gain a better understanding of engineering concepts by obtaining real data from electronic labs. One of such crucial engineering concepts is telecommunications which plays a key role in transmitting information between people, systems and computers. There are many telecommunication schemes which exist today. The iLab developed in this thesis implements an experiment for studying one of such schemes, Amplitude Modulation. The NI ELVIS is used together with a device called the Emona Digital and Analog Telecommunications Experimenter (DATEx) to achieve the Amplitude Modulation lab setup. This iLab is an Interactive iLab, which gives one student at a time complete, real-time control over the lab set up. The Amplitude Modulation iLab will permit students to tune various controls and observe the behavior and changes of relevant signals, both in time domain and frequency domain. It will also permit students to compare different signals and retrieve data locally for post processing.
by Edison M. Achelengwa.
M.Eng.

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Strömberg, Erik. "Modulation and demodulation for radio based pricing." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-199401.

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Lane, William D. "Spread spectrum multi-h modulation." Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/16944.

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Daqing, Huang. "Programming Code-Modulator and Demodulation-Decoder Suited to PCM Systems." International Foundation for Telemetering, 1989. http://hdl.handle.net/10150/614707.

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International Telemetering Conference Proceedings / October 30-November 02, 1989 / Town & Country Hotel & Convention Center, San Diego, California
In order to suit the development of computer telemetry systems, we have developed the intelligent code-modulator and demodulation-decoder. In hardware, they consist of a monolithic processor and some high-integrated devices. Different code or decode ways and several subcarrier modulation or demodulation systems can be varied by carrying out corresponding software programs. In this paper, the equipments' hardware constructions and software cnarts and their main principles are presented.

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Cronin, Christopher Joseph. "Digital frequency demodulation for a laser vibrometer." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-11102009-020344/.

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Xingwen, Ding, Zhong Yumin, Chang Hongyu, and Chen Ming. "Noncoherent Demodulation with Viterbi Decoding for Partial Response Continuous Phase Modulation." International Foundation for Telemetering, 2013. http://hdl.handle.net/10150/579651.

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ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV
With the characteristics of constant envelope and continuous phase, Continuous Phase Modulation (CPM) signal has higher spectrum efficiency and power efficiency than other modulation forms. A noncoherent demodulation with Viterbi decoding for partial response CPM signals is proposed. Simulation results indicate that the demodulation performance of proper partial response CPM is better than the traditional PCM-FM, which is a typical modulation of full response CPM. And higher spectral efficiency is also obtained by partial response CPM.

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Xiros, Nikolaos I. DEng. "Exact Feedback Linearization of Systems with State-Space Modulation and Demodulation." ScholarWorks@UNO, 2019. https://scholarworks.uno.edu/td/2657.

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The control theory of nonlinear systems has been receiving increasing attention in recent years, both for its technical importance as well as for its impact in various fields of application. In several key areas, such as aerospace, chemical and petrochemical industries, bioengineering, and robotics, a new practical application for this tool appears every day. System nonlinearity is characterized when at least one component or subsystem is nonlinear. Classical methods used in the study of linear systems, particularly superposition, are not usually applied to the nonlinear systems. It is necessary to use other methods to study the control of these systems. For a wide class of nonlinear systems, a rather important structural feature comes from the strong nonlinearity appearing as coupling between spectrally decoupled parts of the system. Even in the case of low frequencies, where lumped models can still be employed the nonlinear coupling between parts of the system requires specific treatment, using advanced mathematical tools. In this context, an alternative, frequency domain approach is pursued here. In the rest of this work, a specific system form of linearly decoupled but nonlinearly coupled subsystems is examined. The mathematical toolbox of the Hilbert transform is appropriately introduced for obtaining two low-pass subsystems that form an equivalent description of the essential overall system dynamics. The nonlinear coupled dynamics is investigated systematically by partitioning the coupled system state vector in such a way as to fully exploit the low-pass and the band-pass intrinsic features of free dynamics. In particular, by employing the Hilbert Transform, a low-pass equivalent system is derived. Then, a typical case is investigated thoroughly by means of numerical simulation of the original coupled low and band-pass, real-state-variable system and the low-pass-equivalent, complex-state-variable derived one. The nonlinear model equations considered here pave the way for a systematic investigation of nonlinear feedback control options designed to operate mechatronic transducers in energy harvesting, sensing or actuation modes.

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Krause, Lloyd O., Carlos Reyes-Nieves, and Ivor Frazier. "DPSK MODULATION AND DEMODULATION USING BULK ACOUSTIC WAVE (BAW) DELAY ELEMENTS." International Foundation for Telemetering, 1986. http://hdl.handle.net/10150/615573.

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International Telemetering Conference Proceedings / October 13-16, 1986 / Riviera Hotel, Las Vegas, Nevada
DPSK modulation and demodulation are usually based on logical selection of the difference phase before modulation and the recovery sum phase after detection. Here, we describe an analogue procedure done directly on the PSK’d I-F. BAW delay elements are used in arrangements of feed-forward for difference modulation and of feedback for demodulation. Characteristics are described, and results of laboratory implementation tests for data rate and carrier frequency variations are given. An I-F of 60 MHz and a bit rate of 200 kHz were used as nominal values. Robust performance is indicated.

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Raghu, Swathi. "Combinatorial Modulation and Coherent Demodulation of Bi-orthogonal M-ary Frequency Shift Keying." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1449108844.

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Mao, Chi-heng, and Kun Huang. "The Technology of DBPSK Modulation-Demodulation for Telecommand in Remote Control Test System." International Foundation for Telemetering, 2009. http://hdl.handle.net/10150/606123.

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ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada
This design adopts the software radio and DBPSK（Differential Binary Phase Shift Keying）modulation-demodulation, which detects the telecommand receiving by the guided-missile system correctly. The DBPSK modulation module in Altera FPGA chip converts the binary telecommand into DBPSK signal, which will be frequency modulated after D/A conversion. In the receiver, the FM signal is demodulated and A/D converted before sending to the FPGA. The DBPSK demodulation module in FPGA finally gets the telecommand which will be tally with the telecommand from transmitter. At last, the whole DBPSK modulation-demodulation module is embedded into the remote control test system. The design is working properly and meeting the requirements of the test system.

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Eng, Chun Heong. "Design and development of an automated demodulator calibration station." Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Dec/09Dec%5FEng.pdf.

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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2009.
Thesis Advisor(s): Jenn, David C. Second Reader: Pace, Phillip E. "December 2009." Description based on title screen as viewed on January 28, 2010. Author(s) subject terms: Direct conversion, homodyne, IQ mismatch, DC offsets, IQ circle, phase error, modulator, demodulator calibration, LabVIEW, Directional Finding (DF), digital beamforming, Robust Symmetrical Number System (RSNS). Includes bibliographical references (p. 73-75). Also available in print.

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Rice, Michael, and Oluwasegun Tinubi. "The Range Area Network: A New Approach for Aeronautical Telemetry." International Foundation for Telemetering, 2010. http://hdl.handle.net/10150/605911.

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ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California
The concept of a range area network dedicated to the reception of telemetry from airborne test articles is explored. The range area network consists of ground-based radios that receive telemetry packets from an airborne test article and relay those packets through the network to a data sink (e.g., the main telemetry display and processing center). The network may use either "dumb" nodes or "smart" nodes and this choice presents a trade-off involving node complexity, network bandwidth, and required RF power. Using a somewhat idealized, but nonetheless realistic example at the Edwards AFB complex and link budgets based on the emerging iNET standard, we show that a network consisting of just 6 nodes reduces the L-band airborne transmitter power to 6W and the ground-based transmitters to 3W. If the airborne transmitter is restricted to 1W at L-band, then coverage can be provided by a grid of 50 nodes.

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Lin, Chun-Ching. "Demodulation of Narrowband Radio Frequency Signals by Aliasing Sampling." PDXScholar, 1996. https://pdxscholar.library.pdx.edu/open_access_etds/5286.

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The objective of this thesis is to study the demodulation of narrowband radio frequency signals by aliasing sampling in order to reduce the sampling rate. The spectrum can be recreated at the lower frequency position by aliasing sampling. However, if the sampling rate is deviated from the desired one, error will occur. The sensitivity to the frequency error of aliasing sampling is studied. One main reason of the deviation of the sampling rate is the frequency drifting of the local oscillator. Being able to compensate the oscillator drifting errors inexpensively, automatic frequency control (AFC) loops are important at receivers. Two major digital AFC algorithms are studied. One is the Phase method AFC, and the other is the Magnitude method AFC. Study indicates that both methods perform almost equally well. One adaptive AFC algorithm is also proposed. The scheme of the adaptive AFC algorithm is to use Upper-bound and Lower-bound techniques to squeeze the frequency errors. It is shown that the adaptive AFC algorithm can achieve up to 20 dB average signal-to-noise power ratio over the Magnitude method AFC under a noisy environment.

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Peng, Song, Zhang XiaoLin, Cao Xue, and Qi Xia. "THE APPLICATION OF DIGITAL DEMODULATION TECHNIQUE FOR FREQUENCY MODULATION SIGNAL IN TELEMETRY RECEIVER." International Foundation for Telemetering, 2004. http://hdl.handle.net/10150/604956.

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International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California
Combined with an example of digital telemetry receiver design, this paper mainly discusses the application of software radio in telemetry receiver. The paper begins with an introduction of applying high efficiency digital filter and math analysis in quadrature digital frequency modulation and demodulation to digital frequency conversion technique. Next, Simulink/Matlab is used to simulate digital telemetry receiver. The method of simulation, analysis and calculation of performance and result of simulation are all available. In the end, the paper discusses digital telemetry receiver design and implement by making use of software radio technique, the circuits apply HSP50214 chip of Intersil Co., CPLD implements of Altera Co. and PC Bus. The sample is an expansion card for personal computer. Result of test, performance of the receiver and conclusion are given out, which show fine performance of receiver and can be apply to practice. The lever of this technology has reached first class in the world.

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Yang, Runfeng. "Multiband orthogonal frequency division multiplexing modulation and demodulation for wireless universal serial bus." Thesis, University of Reading, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.499368.

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Wireless Universal Serial Bus (W-USB) has been proposed to offer a mechanism in short range and high speed Wireless Personal Area Networks (WPAN). Wireless USB has now been standardized by utilizing the common WiMedia Ultra Wideband (UWB) radio platform to use the services of Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) as the transport mechanism. With regards to the high data rate mode using DCM modulation scheme, different DCM demapping methods resulting in different system performance are presented, which include soft bit demapping, Maximum Likelihood (ML) soft bit demapping and I Log Likelihood Ratio (LLR) demapping. The proposed Channel State Information (CSl) aided scheme coupled with the band hopping information is used as the further technique to improve the DCM demapping performance.

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Sambaraju, Rakesh. "Photonic Modulation and Demodulation techniques for Multi-Gb/s Millimetre wave Wireless Links." Doctoral thesis, Universitat Politècnica de València, 2010. http://hdl.handle.net/10251/8857.

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Los sistemas de radio sobre fibra(Radio Over fibre ROF) ofrecen el ancho de banda y flexibilidad necesario para la generación y distribución de del señales inalámbricas del futuro en una arquitectura de red óptica, que reduce el coste de las redes centralizando el procesado y simplificando la ubicación de la antena (estación de base EB). El uso de sistemas de comunicaciones ópticas como una media de transporte de señales inalámbricas en enlaces RoF reduce el cuello de botella entre los estándares de acceso inalámbrico y cableado en un dominio convergente óptico. Las redes de acceso ópticas están evolucionando con capacidades de hasta 10 Gb/s con el estándard 10GEPON, dejando un cuello de botella entre tecnologías de acceso inalámbrico y óptico. . Eso ha motivado gran esfuerzo de investigación en la generación y distribución de señales inalámbricas de alta capacidad (> 10 Gb/s) basada en RoF. En esta tesis se ha investigado el uso de técnicas fotónicas para la generación , distribución y demodulación de señales inalámbricas moduladas vectorialmente. Esta tesis está principalmente dedicada a la generación de señales inalámbricas espectralmente eficientes como la modulación de fase en cuadratura (QPSK) o modulación de amplitud cuadratura de multinivel (M-QAM). El trabajo presentado en esta tesis está clasificado en dos partes: la primera de ellas trata de las técnicas fotónicas que utilizan señales eléctricas coherente para la generación y demodulación de señales inalámbricas, mientras la segunda parte trata de usar señales ópticas incoherentes. En la primera parte de la tesis, están presentadas diferentes arquitecturas de sistemas y están analizadas numéricamente, y demostradas experimentalmente. Un nuevo concepto denominado "modulación vectorial fotónica" (PVM) es propuesto para la generación de señales inalámbricas con una modulación M-QAM. Basado en esta técnica se presenta la generación de señales de capacidad 10Gb/s con una modulación de QPSK y 16-QAM.
Sambaraju -, R. (2010). Photonic Modulation and Demodulation techniques for Multi-Gb/s Millimetre wave Wireless Links [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8857
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Ndovi, Lusungu. "Benefits to processor load for quadrature baseband versus radio frequency demodulation algorithms." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/1946.

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A, Sani Negar. "M-PSK and M-QAM Modulation/Demodulation of UWB Signal Using Six-Port Correlator." Thesis, Linköpings universitet, Fysik och elektroteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-64413.

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Nowadays high speed and high data rate communication are highly demanded. Consequently, wideband and high frequency transmitter and receivers should be designed. New transmitters and receivers should also have low power consumption, simple design and low manufacturing price in order to fulfill manufacturers’ requests for mass production. Having all above specifications, six-port correlator is a proper choice to be used as modulator and demodulator in transmitters and receivers. In this thesis the six-port correlator is introduced, modeled and simulated using Advanced Design System (ADS) software. A simple six-port transmitter/receiver system with a line of sight link is modeled and analyzed in BER, path length and noise terms. The modulation in this system is QAM, frequency is 7.5 GHz and symbol rate is 500 Msymbol/s. Furthermore two methods are proposed for high frequency and high symbol rate M-PSK and M-QAM modulation using six-port correlator. The 7.5 GHz modulators are modeled and simulated in ADS. Data streams generated by pseudo random bit generator with 1 GHz bandwidth are applied to modulators. Common source field effect transistors (FETs) with zero bias are used as controllable impedance termination to apply baseband data to modulator. Both modulators show good performance in M-PSK and M-QAM modulation.

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AMIN, AHMED. "Implementation and Investigation of VDSL2 Signal Modulation/Demodulation Functions for FDM Solution via POF Channel." Thesis, Högskolan i Gävle, Avdelningen för elektronik, matematik och naturvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-10766.

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For higher data rate and attractive price level internet service Very High Data rate Subscriber Line 2 (VDSL2) is a perfect option. VDSL2 is a great achievement in Digital Subscriber Line (DSL) technology. It has a good impact in modern triple play (Voice, Data and Video) Internet service but for modern world applications required more data rate than the VDSL2 system can provide but it should be inexpensive and easy to install. So the desired goal of this thesis work is to achieve higher bitrates for VDSL2 system, by transmitting multiple VDSL2 signal using Plastic Optical Fiber (POF) channel instead of copper channel. POF channel is a suitable solution for high data rate application. Moreover POF is very rugged and suitable for high data rate application because of optical based transmission and it’s also very easy to implement into the interior networking. Moreover POF doesn’t have any impact of Electro Magnetic Interference because of optical transmission. So several VDSL2 signals are amplitude modulated to allocate specific frequency band and combined together which can be called as frequency division multiplexing and POF is used as channel to carry the combined signal which provide much higher bit rate than single signal and efficiently utilize the bandwidth of the channel. Then at the receiver end the combined signals are split and amplitude demodulate at the respective receiver to recover the expected frequency band for the receiver.

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Fung, Ka-Cheung Emily. "FEC aided synchronization for group demodulation of preamble-less short burst messages with NCBFSK modulation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ36033.pdf.

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Esmael, Muzeyen Hassen. "Modeling Basic Physical Links in Acumen." Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-18119.

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Simulation is the process of computing a behavior determined by a given model of a system of interest. Modeling is the process of creating a model that formally describes a given class of system. Modeling and simulation can be used to quickly and cheaply study and understand new technologies. Today, a wide range of systems are simulated using different tools. However, converting models into simulation codes can still be difficult and time consuming. In this thesis, we study how a new modeling and simulation language called Acumen can be used to model basic physical links. This language is aimed at bridging the gap between modeling and simulation. We focus on basic physical links as an interesting type of system to model and simulate. We also focus on comparing Acumen to MATLAB and Simulink. The types of links we consider include models of an RC low-pass filter, Amplitude Modulation, Frequency Modulation, Amplitude Shift Keying, Phase Shift Keying and Frequency Shift Keying systems. Each of these examples is modeled in Acumen, MATLAB and Simulink. We find that, for the most part, Acumen allows us to naturally express a wide range of modulation techniques mentioned above. When compared to MATLAB ad Simulink, we find that Acumen is simple language to understand. Acumen codes are described in a more natural way. Simplicity is the biggest advantage of Acumen.

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Cirineo, Tony, and Bob Troublefield. "STANDARD INTEROPERABLE DATALINK SYSTEM, ENGINEERING DEVELOPMENT MODEL." International Foundation for Telemetering, 1995. http://hdl.handle.net/10150/608398.

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International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada
This paper describes an Engineering Development Model (EDM) for the Standard Interoperable Datalink System (SIDS). This EDM represents an attempt to design and build a programmable system that can be used to test and evaluate various aspects of a modern digital datalink. First, an investigation was started of commercial wireless components and standards that could be used to construct the SIDS datalink. This investigation lead to the construction of an engineering developmental model. This model presently consists of wire wrap and prototype circuits that implement many aspects of a modern digital datalink.

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Javidi, Giti. "A comparison of traditional physical laboratory and computer simulated laboratory experiences in relation to engineering undergraduate students conceptual understandings of a communication systems topic." Scholar Commons, 2005. http://scholarcommons.usf.edu/etd/2936.

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This study was designed to investigate an alternative to the use of traditional physical laboratory activities in a communication systems course. Specifically, this study examined whether as an alternative, computer simulation is as effective as physical laboratory activities in teaching college-level electronics engineering education students about the concepts of signal transmission, modulation and demodulation. Eighty undergraduate engineering students participated in the study, which was conducted at a southeastern four-year university. The students were randomly assigned to two groups. The groups were compared on understanding the concepts, remembering the concepts, completion time of the lab experiments and perception toward the laboratory experiments. The physical groups (n=40) treatment was to conduct laboratory experiments in a physical laboratory. The students in this group used equipment in a controlled electronics laboratory. The Simulation groups (n=40) treatment was to conduct similar experiments in a PC laboratory. The students in this group used a simulation program in a controlled -PC lab. At the completion of the treatment, scores on a validated conceptual test were collected once after the treatment and again three weeks after the treatment. Attitude surveys and qualitative study were administered at the completion of the treatment. The findings revealed significant differences, in favor of the simulation group, between the two groups on both the conceptual post-test and the follow-up test. The findings also revealed significant correlation between simulation groups attitude toward the simulation program and their post-test scores. Moreover, there was a significant difference between the two groups on their attitude toward their laboratory experience in favor of the simulation group.

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Ganesan, Aravind. "Capacity estimation and code design principles for continuous phase modulation (CPM)." [College Station, Tex. : Texas A&M University, 2003. http://hdl.handle.net/1969.1/53.

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Thesis (M.S.)--Texas A&M University, 2003.
"Major Subject: Electrical Engineering" Title from author supplied metadata (record created on Jul. 18, 2005.) Vita. Abstract. Includes bibliographical references.

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Culha, Onur. "Noncoherent Differential Demodulation Of Cpm Signals With Joint Frequency Offset And Symbol Timing Estimation." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613729/index.pdf.

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In this thesis, noncoherent differential demodulation of CPM signals with joint carrier frequency offset and symbol timing estimation is investigated. CPM is very attractive for wireless communications owing to major properties: good spectral efficiency and a constant envelope property. In order to demodulate the received CPM signal differentially, the symbol timing and the carrier frequency offset have to be estimated accurately. There are numerous methods developed for the purpose. However, we have not encountered studies (which are based on autocorrelation estimation and hence suitable for blind synchronization) that give expectable performance for both M-ary and partial response signaling. Thus, in this thesis we analyze a feedforward blind estimation scheme, which recovers the symbol timing and the frequency offset of M-ary CPM signals and partial response CPM signals. In addition, we surveyed low complexity symbol detection methods for CPM signals. Reduced state Viterbi differential detector incorporated to the joint frequency offset and symbol timing estimator is also examined. The performance of the examined demodulator scheme is assessed for the AWGN channel by computer simulations.

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Marzolini, Remo G. A. "Demodulator techniques in satellite communications systems for direct broadcast systems." n.p, 1995. http://ethos.bl.uk/.

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Monica, G. Della, and E. Tonello. "NEW GENERATION COMMAND RECEIVER FOR SATELLITE USING BENEFITS OF DIGITAL PROCESSING." International Foundation for Telemetering, 1998. http://hdl.handle.net/10150/607344.

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International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California
Presentation of Alcatel Espace last studies and developments regarding TT&C receiver Products for satellite. This document lays on 3 parts: · a technical point of view showing digital demodulation principles used (base band recovery, analytical head, PM or FM demodulation) and their related offered possibilities(digital controlling loop, lock status detection, jammer detection,....) · a technology/design description · a synthesis showing performance and results

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Ortega, Espluga Lorenzo. "Signal optimization for Galileo evolution." Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0118.

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Les systèmes mondiaux de navigation par satellite (GNSS) sont de plus en plus présents dansnotre vie quotidienne. Des nouveaux utilisateurs émergent avec des besoins opérationnelssupplémentaires, ce qui implique une évolution constante des systèmes de navigation actuels.Dans le cadre de Galileo (système GNSS européen) et en particulier dans Galileo E1 OpenService (OS), l’addition d’un nouveau signal d’acquisition pourrait contribuer à améliorer larésilience dans la phase d’acquisition et à réduire le temps pour géo-localiser notre récepteur(TTFF). La conception d'un nouveau signal GNSS est toujours un compromis entre plusieursfigures de mérite. Les plus pertinents sont la précision de la position, la sensibilité de récepteur etle TTFF. Cependant, si l’on considère que la phase d’acquisition du signal le principal objectif, lasensibilité et le TTFF ont une pertinence plus grande. Compte tenu de ce qui précède, dans cettethèse, il est présenté la conception conjointe d'un signal GNSS avec la structure de message afinde proposer un nouveau signal Galileo de deuxième génération, qui offre bonne sensibilité derécepteur ainsi que une réduction dans le TTFF. Plusieurs aspects ont été abordés afin deconcevoir la nouvelle composante de signal. Premièrement, la définition de la modulation doitprendre en compte la compatibilité des fréquences radioélectriques afin de provoquer un niveaude brouillage acceptable dans la bande. De plus, la modulation devrait fournir de bonnespropriétés de corrélation et une bonne résistance contre les multi trajets afin d'améliorer lasensibilité du récepteur. Deuxièmement, le choix du nouveau code PRN est également crucialpour faciliter la phase d’acquisition. Un critère de modélisation basé sur une fonction de coûtpondéré est utilisé pour évaluer la performance des codes PRN. Cette fonction de coût considèredifférent facteurs telles que l'autocorrélation, la corrélation croisée et la densité spectrale depuissance. Troisièmement, une conception conjointe entre la structure de message et le schémade codage de canal peut fournir à la fois une réduction du TTFF et une amélioration de larésilience des données décodées. Alors, une nouvelle méthode de conception de la structure demessage et du schéma de codage de canal pour le nouveau signal est proposée. Cette méthodefournit les instructions pour concevoir une structure de message dont le schéma de codage decanal est caractérisé pour les propriétés full diversity, maximum distance separable et ratecompatibility. Le codage de canal est essentiel pour améliorer les performances de démodulationde données, en particulier dans les environnements très obstrué ou avec d’interférences.Cependant, ce processus peut être très sensible au calcul correct de l'entrée du décodeur. Desaméliorations significatives ont été obtenues en considérant «soft » décodeurs, via le calcul deslog-likelihood ratio (LLR). Malheureusement, la connaissance complète des informations d'état ducanal (CSI) était généralement prise en compte, ce qui est rarement le cas dans des scénariosréels. Dans cette thèse, nous fournissons de nouvelles méthodes pour calculer desapproximations linéaires du LLR, sous les canaux de fading et interférence, en considérantcertaine information statistique sur le CSI. Finalement, transmettre un nouveau signal dans lamême fréquence porteuse et en utilisant le même amplificateur de puissance (HPA) génère descontraintes dans les méthodes de multiplexage, car une enveloppe constante ou quasi constanteest nécessaire pour réduire les distorsions non linéaires. Également, la conception dumultiplexage devrait offrir une efficacité énergétique élevée afin de ne pas gaspiller l'énergietransmis du satellite. Considérant le précédent, dans cette thèse, nous évaluons différentesméthodes de multiplexage, qui cherchent l’intégration de un nouveau signal binaire dans la bandeGalileo E1
Global Navigation Satellite System (GNSS) are present in our daily lives. Moreover, new users areemerging with further operation needs involving a constant evolution of the current navigationsystems. In the current framework of Galileo (GNSS European system) and especially within theGalileo E1 Open Service (OS), adding a new acquisition aiding signal could contribute to providehigher resilience at the acquisition phase, as well as to reduce the time to first fix (TTFF).Designing a new GNSS signal is always a trade-off between several performance figures of merit.The most relevant are the position accuracy, the sensitivity and the TTFF. However, if oneconsiders that the signal acquisition phase is the goal to design, the sensitivity and the TTFF havea higher relevance. Considering that, in this thesis it is presented the joint design of a GNSS signaland the message structure to propose a new Galileo 2nd generation signal, which provides ahigher sensitivity in the receiver and reduce the TTFF. Several aspects have been addressed inorder to design a new signal component. Firstly, the spreading modulation definition must considerthe radio frequency compatibility in order to cause acceptable level of interference inside the band.Moreover, the spreading modulation should provide good correlation properties and goodresistance against the multipath in order to enhance the receiver sensitivity and to reduce theTTFF. Secondly, the choice of the new PRN code is also crucial in order to ease the acquisitionphase. A simple model criterion based on a weighted cost function is used to evaluate the PRNcodes performance. This weighted cost function takes into account different figures of merit suchas the autocorrelation, the cross-correlation and the power spectral density. Thirdly, the design ofthe channel coding scheme is always connected with the structure of the message. A joint designbetween the message structure and the channel coding scheme can provide both, reducing theTTFF and an enhancement of the resilience of the decoded data. In this this, a new method to codesign the message structure and the channel coding scheme for the new G2G signal isproposed. This method provides the guideline to design a message structure whose the channelcoding scheme is characterized by the full diversity, the Maximum Distance Separable (MDS) andthe rate compatible properties. The channel coding is essential in order to enhance the datademodulation performance, especially in harsh environments. However, this process can be verysensitive to the correct computation of the decoder input. Significant improvements were obtainedby considering soft inputs channel decoders, through the Log Likelihood Ratio LLRs computation.However, the complete knowledge of the channel state information (CSI) was usually considered,which it is infrequently in real scenarios. In this thesis, we provide new methods to compute LLRlinear approximations, under the jamming and the block fading channels, considering somestatistical CSI. Finally, to transmit a new signal in the same carrier frequency and using the sameHigh Power Amplifier (HPA) generates constraints in the multiplexing design, since a constant orquasi constant envelope is needed in order to decrease the non-linear distortions. Moreover, themultiplexing design should provide high power efficiency to not waste the transmitted satellitepower. Considering the precedent, in this thesis, we evaluate different multiplexing methods,which search to integrate a new binary signal in the Galileo E1 band while enhancing thetransmitted power efficiency. Besides that, even if the work is focused on the Galileo E1, many ofthe concepts and methodologies can be easily extended to any GNSS signal

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Larroque, Joël. "Etude, conception et realisation d'un demodulateur a remodulation quadriphase : application a la regeneration du signal dans les satellites de telecommunications ou de relais de donnees." Toulouse 3, 1988. http://www.theses.fr/1988TOU30087.

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Ce memoire presente l'etude d'un demolutateur a remodulation quadriphase a la frequence de b, 87 ghz permettant la regeneration des signaux hyperfrequence a bord des satellites de telecommunications (a acces multiples commutes a bord) ou de relais de donnees (pour les liaisons avec des satellites ou des navettes en orbite basse ainsi qu'avec des mobiles terrestres. Le demodulateur a remodulation quadriphase est compose de sous-equipements dont une simulation permet de connaitre leurs influences sur les performances du systeme complet

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M, M. Galib Asadullah. "Robust wireless communications under co-channel interference and jamming." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22571.

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Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Gordon L. Stuber; Committee Member: Alfred D. Andrew; Committee Member: John A. Buck; Committee Member: Steven W. McLaughlin; Committee Member: Ye (Geoffrey) Li.

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Umar, Muhammad, and Umar Yasir. "Differential Six-Port Transceiver Design and Analysis from a Wireless Communication System Perspective." Thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-78943.

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In modern telecommunication there is the demand of high data rates using wideband component design. FCC has introduced the UWB spectrum for high speed data communication. UWB systems have attracted the attention of researchers. Six-port transmitters and receivers are strong candidates for UWB systems and research is being done on six-port modulators and demodulators. In this work an effort is made to compare the performance of conventional single-ended six-port transmitter and receiver with differential six-port transmitters and receivers. In this thesis, single ended and differential six-port correlators are designed on 7.5 GHz using Agilent Inc. EDA tool ADS and their performance is evaluated. A new wide-band differential six-port correlator is implemented using rat-race couplers and double-sided parallel strip-line phase inverter. The designed six-port correlators are used for 8-PSK modulation and demodulation. For transmitter-receiver system, mixed analog-DSP designing is used. The integral components of the system are evaluated individually and behavioral modeling is used to evaluate the complete transmitter-receiver system. The single-ended and differential systems are evaluated for noise-figure, dynamic range, bit error rate and data rate.

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Yu, Hyungseok. "Performance of cooperative relaying systems with co-channel interference." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45744.

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The cooperative relaying scheme is a promising technique for increasing the capacity and reliability of wireless communication. Even though extensive research has performed in information theoretical aspect, there are still many unresolved practical problems of cooperative relaying system. This dissertation analyzes the performance of cooperative decode-and-forward (DF) relaying systems in the presence of multiple interferers and improve network throughput for these systems. We propose and summarize various systems in the view of network topology, transmission structure, and slot allocation. We present closed-form expressions for the end-to-end outage probability, average symbol-error-probability, average packet-error-probability, and network throughput of the proposed systems. This dissertation shows that the robustness of the destination against interference is more important than robustness of the relay against interference from an interference management perspective, and increasing the number of branches yields better outage and error performance improvements against shadowing than increasing the number of hops. In cellular networks, the cooperative diversity systems can outperform the dual-Rx antenna system, but only when the relay is located in a relatively small portion of the total cell area with respect the the destination mobile terminal. The results also show that since the effective regions of the uplink and the downlink do not overlap, different relays should be utilized for cell sectorization in the uplink and the downlink. Finally, the proposed variable-slot selection DF scheme can reduce the system complexity and make the maximum throughput point in the low and moderate signal-to-interference-plus-noise ratio region.

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Das, Sibasish. "Analysis and design of pilot-aided multicarrier systems over doubly selective channels with a local subcarrier processing constraint." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1199305333.

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Shaddock, Daniel Anthony, and Daniel Shaddock@jpl nasa gov. "Advanced Interferometry for Gravitational Wave Detection." The Australian National University. Faculty of Science, 2001. http://thesis.anu.edu.au./public/adt-ANU20020227.171850.

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In this thesis we investigate advanced techniques for the readout and control of various interferometers. In particular, we present experimental investigations of interferometer configurations and control techniques to be used in second generation interferometric gravitational wave detectors. We also present a new technique, tilt locking, for the readout and control of optical interferometers. ¶ We report the first experimental demonstration of a Sagnac interferometer with resonant sideband extraction (RSE). We measure the frequency response to modulation of the length of the arms and demonstrate an increase in signal bandwidth of by a factor of 6.5 compared to the Sagnac with arm cavities only. We compare Sagnac interferometers based on optical cavities with cavity-based Michelson interferometers and find that the Sagnac configuration has little overall advantage in a cavity-based system. ¶ A system for the control and signal extraction of a power recycled Michelson interferometer with RSE is presented. This control system employs a frontal modulation scheme requiring a phase modulated carrier field and a phase modulated subcarrier field. The system is capable of locking all 5 length degrees of freedom and allows the signal cavity to be detuned over the entire range of possibilities, in principle, whilst maintaining lock. We analytically investigate the modulation/demodulation techniques used to obtain these error signals, presenting an introductory explanation of single sideband modulation/demodulation and double demodulation. ¶ This control system is implemented on a benchtop prototype interferometer. We discuss technical problems associated with production of the input beam modulation components and present several solutions. Operation of the interferometer is demonstrated for a wide range of detunings. The frequency response of the interferometer is measured for various detuned points and we observe good agreement with theoretical predictions. The ability of the control system to maintain lock as the interferometer is detuned is experimentally demonstrated. ¶ Tilt locking, a new technique to obtain an error signal to lock a laser to an optical cavity, is presented. This technique produces an error signal by efficient measurement of the interference between the TEM00 and TEM10 modes. We perform experimental and theoretical comparisons with the widely used Pound-Drever-Hall (PDH) technique. We derive the quantum noise limit to the sensitivity of a measurement of the beam position, and using this result calculate the shot noise limited sensitivity of tilt locking. We show that tilt locking has a quantum efficiency of 80%, compared to 82% for the PDH technique. We present experimental demonstrations of tilt locking in several applications including frequency stabilisation, continuous-wave second harmonic generation, and injection locking of a Nd:YAG slab laser. In each of these cases, we demonstrate that the performance of tilt locking is not the limiting factor of the lock stability, and show that it achieves similar performance to the PDH based system. ¶ Finally, we discuss how tilt locking can be effectively applied to two beam interferometers. We show experimentally how a two beam interferometer typically gives excellent isolation against errors arising from changes in the photodetector position, and experimentally demonstrate the use of tilt locking as a signal readout system for a Sagnac interferometer.

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Kroupa, Martin. "Analýza změny zátěže asynchronního motoru z měření statorových proudů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221189.

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This thesis is focused on the evaluation of rotor dynamics of the induction machine, which can be used as a basis for online diagnosis of driven load in the future. It describes the problem of time varying loading torque at its impact to electromagnetic variables in induction machine. Followed by the possible ways of monitoring and diagnostic of loading torque using Fourier analysis on supply current.

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Jacobsson, Fredrik. "DPSK modulation format for optical communication using FBG demodulator." Thesis, Linköping University, Department of Science and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2307.

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The task of the project was to evaluate a differential phase shift keying demodulation technique by replacing a Mach-Zehnder interferometer receiver with an optical filter (Fiber Bragg Grating). Computer simulations were made with single optical transmission, multi channel systems and transmission with combined angle/intensity modulated optical signals. The simulations showed good results at both 10 and 40 Gbit/s. Laboratory experiments were made at 10 Gbit/s to verify the simulation results. It was found that the demodulation technique worked, but not with satisfactory experimental results. The work was performed at Eindhoven University of Technology, Holland, within the framework of the STOLAS project at the department of Electro-optical communication.

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Laha, Soumyasanta. "Analysis & Design of Radio Frequency Wireless Communication Integrated Circuits with Nanoscale Double Gate MOSFETs." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1418730974.

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Geoghegan, Mark. "DESCRIPTION AND PERFORMANCE RESULTS FOR THE ADVANCED RANGE TELEMETRY (ARTM) TIER II WAVEFORM." International Foundation for Telemetering, 2000. http://hdl.handle.net/10150/606485.

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International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California
The Advanced Range Telemetry (ARTM) program is a tri-service telemetry modernization project whose goal is to assure that all Department of Defense (DoD) test and training ranges are able to use telemetry as necessary to carry out their respective missions. Multi-h Continuous Phase Modulation (CPM) has been selected by the ARTM JPO as the Tier II ARTM waveform, because it offers significant improvements over both legacy telemetry waveforms (PCM/FM) and the newly-introduced Tier I waveform (Feher-patented FQPSK) in terms of spectral containment and detection efficiency, while retaining a constant envelope characteristic. The paper describes the theoretical and measured performance of the ARTM Tier II multi-h CPM waveform, and the implementation of the trellis demodulator being developed for it.

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Hladký, David. "Realizace úzce směrového akustického měniče." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242007.

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The present final thesis discusses the transmission of a narrowly directional parametric sound beam through an amplitude-modulated ultrasonic wave, utilizing the effect of auto-demodulation in a nonlinear medium and ensuring the subsequent processing of the input signal for the parametric sound transmitter. Emphasis is placed on the mathematical tools that relate to parametric sound transmission in a nonlinear medium. The basic part of the thesis describes a parametric speaker and the associated amplitude modulation techniques, which constitute a major prerequisite for the processing of the transmitted signal. In the following section, the author then analyzes the computational intensity of these techniques, considering applicable hardware approaches. Finally, the fabrication and practical use of the proposed solution are discussed, including the measurement of typical parameters such as the spatial radiation characteristics, total harmonic distortion, and transmission channel bandwidth.

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41

Wahlgren, Max, and Daniel Forsberg. "Hårdvarubaserade SOQPSK-algoritmer : En VHDL-implementation av algoritmer för att modulera & demodulera SOQPSK-signaler." Thesis, Linköping University, Department of Science and Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-12327.

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Beroende på i vilken miljö man har tänkt att använda trådlös kommunikation behöver man hitta en modulationsteknik som passar under rådande förhållanden. I början på 1980-talet utvecklade den Amerikanska militären en modulationsteknik som kallas för Shaped BPSK (SBPSK) avsedd att tillämpas i kommunikationslänkar med satelliter. Vidareutveckling av SBPSK ledde sedan fram till en förbättrad variant kallad Shaped Oﬀset QPSK (SOQPSK). På senare år har denna modulationsteknik börjat användas i civila tillämpningar och vidareutvecklats ytterligare för att ge den än bättre prestanda. År 2004 antogs SOQPSK som en modulationsteknik i den internationella ﬂygplanskommunikationsstandarden, IRIG-106. Versionen av SOQPSK som antogs i IRIG-106 har ﬂera bra egenskaper som t. ex. dess spektraltäthet. Detta gör denna typ av modulationsteknik lämpad för kommunikationslänkar med bl.a. ﬂygplan, satelliter och rymdsonder (‘deep-space’).

Målet med examensarbetet har varit att implementera algoritmer för att skicka och ta emot SOQPSK-modulerade signaler. Dessa algoritmer skulle utvecklas i VHDL för att sedan syntetiseras och programmera en FPGA. Uppgiften har givits av Syncore Technologies AB i Linköping.

Arbetet har resulterat i fungerande implementationer både i mjukvara och hårdvara. Hårdvarulösningen är veriﬁerad att klara bithastiheter upp till 30 Mbit/s. Teoretisk information om allmän modulering/demodulering och speciﬁkt kring SOQPSK behandlas i rapporten. Uppbyggnaden av en teoretisk sändar- och mottagarmodell utformad för SOQPSK-kommunikation beskrivs också i rapporten för att ge en bättre helhetsbild av implementationen som utförts.

Arbetets syfte är att ligga till grund för Syncore AB som utvecklar en kom- munikationslänk med SOQPSK-kompatibilitet.

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Murray, Terrence J. "Four frequency-shift keying (4-FSK) spread spectrum modulator and demodulator." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA267433.

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43

Cuthbert, James. "High performance non-symmetric multi-h CPFSK modulator and demodulator design." Doctoral thesis, University of Cape Town, 1997. http://hdl.handle.net/11427/21325.

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The continuity properties of the CPFSK signal at it's symbol-period boundaries reveals an inherent memory contained in the transmitted signal. This is utilized as an error correction property. Furthermore, it was shown that the Multi-h CPFSK construction can be accomplished through the combination of a block constructing the memoryless component of the signal and either a block of digital logic circuitry or a continuous phase encoder constructing the memory component. The implementation of the first method was seen to function through simulations performed by using the TESLA simulation package. An extensive search for good Multi-h CPFSK h-sets was performed. The criteria for determining the performance of these h-sets was the Probability of Error gains over Minimum Shift Keying. The method of search was novel to this work. Specifically, a genetic search algorithm known as the Population Based Incremental Learning algorithm was utilized. The algorithm was implemented through the C++ programming language Faster error correction convolutional decoding algorithms were reviewed. Certain decoders exhibit lighter hardware demands, and in specific applications, are less susceptible to erasure problems. The Fano algorithm was selected as the best alternative to the Viterbi algorithm and was modified for the CPFSK implementation. The functionality of the implementation was tested using a C++ simulation. Various structures used to implement the synchronization and demodulation of Multi-hCPFSK were investigated. The most comprehensive structure that could be found was a scheme developed by Premji and Taylor using maximum likelihood techniques. This scheme was selected as it can be easily modified for the use with the large state, high speed implementation of non-symmetric Multi-h CPFSK investigated in this thesis. The PBIL algorithm was found to be an efficient method for finding good h-sets with large numbers of phase states. Theoretical gains over MSK using this method were found to be significant. It was concluded that the Fano decoder is highly applicable to the demodulator structure proposed in this thesis and is a preferred alternative to the Viterbi decoder under specific circumstances.

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Melša, Ondřej. "Generátor modulovaných signálů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218641.

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This project occupies with the creation modulated signal generator in MATLAB. There are explicit basic princips of modulation PSK, M-QAM, princip of system with spread spektrum and princip of access OFDM and MC-CDMA. Next there are explicit basic parametres and possibilities configuration of conversion analog PCI card CompuGen 4302, which serves as D/A convertor of signals created by PC.

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45

Khatami, Mehrdad. "combined Modulation and Error Correction Decoder for TDMR Using Generalized Belief Propagation." International Foundation for Telemetering, 2013. http://hdl.handle.net/10150/579681.

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ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV
Constrained codes also known as modulation codes are a key component in the digital magnetic recording systems. The constrained codes forbid particular input data patterns which lead to some of the dominant error events or higher media noise. In data recording systems, a concatenated approach toward the constrained code and error-correcting code (ECC) is typically used and the decoding is done independently. In this paper, we show the improvement in combining the decoding of the constrained code and the ECC using generalized belief propagation (GBP) algorithm. We consider the performance of a combined modulation constraints and the ECC on a binary symmetric channel (BSC). We show that combining demodulation and decoding results in a superior performance compared to concatenated schemes. Furthermore, we compute the capacity of the joint ECC and modulation codes for 1-D and 2-D constraints.

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46

Chawah, Patrick. "DÉVELOPPEMENT D'UN CAPTEUR DE DÉPLACEMENT À FIBRE OPTIQUE APPLIQUÉ À L'INCLINOMÉTRIE ET À LA SISMOLOGIE." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2012. http://tel.archives-ouvertes.fr/tel-00779335.

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Le suivi de la déformation de la croûte terrestre durant la phase intersismique pour la recherche des transitoires nécessite des instruments précis capables d'opérer pour de très longues durées. Le projet ANR-LINES a visé le développement de trois nouveaux instruments : un sismomètre mono-axial, un inclinomètre hydrostatique à longue base et un inclinomètre de forage pendulaire. Ces trois instruments profitent d'un capteur interférométrique de déplacement à longues fibres optiques du type Fabry-Pérot Extrinsèque (EFFPI). Leurs architectures mécaniques et l'utilisation de longues fibres permettent à ces instruments géophysiques nouvellement fabriqués d'atteindre les objectifs fixés. Le premier objectif de cette étude est de proposer des méthodes adaptées à l'estimation de la phase du chemin optique dans les cavités Fabry-Pérot. Une modulation du courant de la diode laser, suivie par une démodulation homodyne du signal d'interférence et un filtre de Kalman permettent de déterminer la phase en temps réel. Les résultats sont convaincants pour des mesures de courtes durées mais exigent des solutions complémentaires pour se prémunir des effets de la variation des phénomènes environnementaux. Le capteur EFFPI intégré dans l'inclinomètre de forage LINES lui offre l'opportunité d'établir une mesure différentielle de l'oscillation de la masselotte pendulée grâce à trois cavités Fabry-Pérot. Le sismomètre LINES utilise lui aussi le capteur de déplacement EFFPI pour la mesure du déplacement de sa bobine. Une description de l'architecture mécanique de ces instruments et une analyse des phénomènes détectés (mouvements lents, marées, séismes, microséismes . . . ) font partie de cette thèse.

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47

Dubbert, Dale F. "The RMS phase error of a phase-locked loop FM demodulator for standard NTSC video." Thesis, Kansas State University, 1986. http://hdl.handle.net/2097/9911.

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Garcia, João. "Aplicação de Redes Neuronais de Competição à Desmodulação de Sinal em Modulação Digital." Master's thesis, Department of Informatics, University of Lisbon, 2002. http://hdl.handle.net/10451/14001.

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This work applies a pattern recognition system based on artificial neural networks to the demodulation of digitally modulated signals. It is intended to explore the ability that may be displayed by neural networks to reconstruct patterns corrupted by noise. A competition neural network is presented that is able to perform digital modulation reception tasks: frequency and phase carrier synchronization; symbol synchronization; systematic compensation of symbol rotation. Some tasks imply post-processing of neural network output. The presented system does not require carrier synchronization with a local oscillator. Same details of the proposed methods are new contributions, which are stressed upon discussion. It was indented to guarantee future implementation of the neural network using programmable logic arrays. It is necessary to limit the proposed architecture size to an acceptable number of logical gates. On the other hand it is necessary to guarantee that each given stimulus vector is fully processed before the next one arrives (assuring real time operation). This work is mainly focused on 4-PSK (or QPSK) modulation, since this kind of modulation is used in a wide range of digital modulation applications (including third generation mobile phones). Generalization possibilities to M-PSK and M-QAM are discussed. Simulation methods were applied to evaluate system performance. Results indicate that the system is able to perform accordingly to objectives

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Ghuman, Parminder, Steve Koubek, Tom Winkert, Andrew Gray, Norm Lay, and Tsun-Yee Yan. "ULTRA HIGH BIT RATE (UP TO 1GBIT/S) BANDWIDTH EFFICIENT FQPSK ALL-DIGITAL MODULATOR/DEMODULATOR ARCHITECTURES AND NASA IMPLEMENTATIONS." International Foundation for Telemetering, 2000. http://hdl.handle.net/10150/607703.

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International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California
The paper presents ongoing efforts at NASA’s Goddard Space Flight Center and the Jet Propulsion Laboratory to develop ultra high bit rate bandwidth efficient FQPSK modulators and demodulators. The ability to transmit and receive ever-increasing amounts of extremely high rate data is an enduring challenge in the arena of near-earth space borne science missions. Reliable and efficient transmission of information at these data rates requires the use of power and bandwidth efficient modulations that exhibit low transmitter, receiver, and decoder complexity. Conventional high rate approaches for achieving spectral limiting typically employ sharp post amplifier filtering at the transmitter to limit the interference to the adjacent bands. However, using analog filtering alone can produce substantial intersymbol interference and other distortions that substantially affect the detection performance of the signal. In contrast, various theoretical classes of modulation waveforms can be tailored to provide varying degrees of bandwidth and power efficiency or robustness to non-linear transmitter distortions while incurring little or no performance losses. In order to realize many of these signal types, precise amplitude and phase control over the synthesis of these signals is required, typically necessitating the use of digital signal processing.

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Sousa, Fernando Rangel de. "Application du corrélateur " Five-Port " aux PLLs, à la récupération de porteuse et à un MODEM de télécommunications dans la bande 1,8 - 5,5 Ghz." Paris, ENST, 2004. https://pastel.archives-ouvertes.fr/pastel-00000987.

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Abstract:

Le corrélateur "Five-Port" est un dispositif qui calcule précisément le rapport complexe entre deux signaux hyperfréquences à partir de la mesure des valeurs de puissance aux sorties d'un circuit interférométrique à cinq accès. Son application est connue dans les systèmes radars, les systèmes de détermination de la direction d'arrivée de signaux RF, les démodulateurs homodynes et, comme nous proposons dans ce travail, dans les boucles à verrouillage de phase et de récupération de porteuse. Tandis que les corrélateurs cartésiens classiques projettent le vecteur représentant le signal à démoduler sur une base composée de deux vecteurs orthogonaux, le corrélateur "Five-Port" effectue cette projection sur une "base" à trois vecteurs décalés en phase idéalement de 120°. Grâce à la redondance introduite par le troisième vecteur, le corrélateur "Five-Port" se présente moins sensible aux désappariements de phase et d'amplitude, fournit une variable permettant d'estimer les produits inter-modulation d'ordre pair et peut fonctionner dans une bande de fréquences large. Cette thèse apporte quelques contributions au domaine de la radiocommunication mobile, notamment aux émetteurs-récepteurs multi-bande et multi-mode. Le premier apport original est l'application de la technique "Five-Port" aux boucles à verrouillage de phase reconfigurables. Cette application est exploitée par la suite dans une boucle de récupération de porteuse multi-mode. Ensuite nous proposons une méthode de caractérisation originale mise en place pour calibrer les corrélateurs \FiveP. Finalement nous proposons et évaluons une nouvelle architecture d'émetteur-récepteur fondée sur une base à trois vecteurs
The five-port correlator accurately computes the complex ratio between two radiofrequency signals from the power values measured at the output of a five-port interferometer circuit. Its application has been reported in radars, DOA systems, direct conversion receivers and, as we propose in this work, in PLLs and carrier recovery loops. Whereas classic cartesian correlators project a vector representing a modulated signal over an orthogonal basis, the five-port correlator performs this projection over a \textsl{basis} composed of three vectors ideally phase-shifted of 120°. Thanks to the redundancy added by the third vector, the five-port correlator is less sensible to phase and amplitude imbalances, allows for the estimation of the IM2 products and operates in a wider frequency band. This PhD research contributes to the mobile radiocommunication area, in particular to the multi-mode and multi-band transceivers. The first contribution is the application of the five-port technique to reconfigurable phase-locked loops. Secondly, these reconfigurable loops are exploited in a multi-mode carrier recovery loop. Then, we present an original five-port characterization method. Finally, we propose and evaluate a novel transceiver architecture based on a three-vector basis

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Dissertations / Theses on the topic 'Modulation and Demodulation'

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