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Kontodios, Pierros. "Performance analysis of noncoherent Binary Frequency Shift Keying using Equal Gain Combining and Post Detection Selection Combining over a Nakagami fading channel." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA354305.
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Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, September 1998."September 1998." Thesis advisor(s): Tri T. Ha, Ralph D. Hippenstiel. Includes bibliographical references (p. 97). Also available online.
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Svenningsen, Juan P. "Modeling, simulation and implementation of a non-coherent binary-frequency-shift-keying (BFSK) receiver-transmitter into a field programmable gate array (FPGA)." Thesis, Monterey, California. Naval Postgraduate School, 2005. http://hdl.handle.net/10945/2098.
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This thesis presents the use of a field programmable gate array (FPGA) to implement a non-coherent binary-frequency-shift-keyed receiver-transmitter (BFSK-RT) that simulates the modulation of the SINCGARS radio, the RT-1523C. An FPGA successfully, and with very few resources, implemented the desired modulation and demodulation. Topics covered include FPGA history, the hardware and software utilized, a summary of the SINCGARS RT-1523C characteristics, the BFSK-RT on FPGA design procedure and the design results.
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Svenningsen, Juan P. "Modeling, simulation and implementation of a non-coherent binary-frequency-shift-keying (BFSK) receiver-transmitter into a field program-mable gate array (FPGA) /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FSvenningsen.pdf.
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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, September 2005.Thesis Advisor(s): Herschel Loomis, Frank Kragh. Includes bibliographical references (p. 83-85). Also available online.
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Ma, Rui, Martin Kreißig, Florian Protze, Frank Ellinger, Purbawati, Ruiz-Calaforra, Hem, and Ursula Ebels. "Spin Toqure Oscillator Based BFSK Modulation." IEEE / Institute of Electrical and Electronics Engineers Incorporated, 2017. https://tud.qucosa.de/id/qucosa%3A35059.
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This work presents a spin torque nano-oscillator (STNO) based binary frequency shift keying (BFSK) modulation schema implemented on a printed circuit board (PCB). Maximal input data rate reaches 20 Mbit/s. Depending on the STNO used, carrier frequency can range from 1 to 10 GHz. Both DC and AC currents flowing through the STNO can be tuned between 0 to 4 mA. Using one magnetic tunnel junction (MTJ) STNO, a 380 MHz frequency shift around the center frequency 9 GHz was observed, when the modulated current was toggled between 0.8 mA and 1.2 mA at a rate of 20 Mbit/s. This is the first work demonstrating that the STNOs are applicable for BFSK modulation on the wireless application level.
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Jung, Du San. "Detection of binary phase-shift keying signal in multipath propagation." Monterey, California: Naval Postgraduate School, 2002, 2002. http://hdl.handle.net/10945/9763.
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Time-varying dispersion and multipath propagation in a shallow underwater environment causes intersymbol interference in underwater communication. This thesis investigates a mitigation procedure for communication using a Binary Phase-Shift Keying (BPSK) signal. The method employed uses the time-reversed ocean impulse response to mitigate the degradation of the bit error rate performance. All results were achieved by the use of computer simulation of typical shallow water environments.
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Jung, Du San. "Detection of binary phase-shift keying signal in multioath propagation." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Jun%5FJung.pdf.
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Harrington, Riley T. "Frequency shift keying demodulators for low-power FPGA applications." Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/35101.
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Master of ScienceDepartment of Electrical and Computer Engineering
Dwight D. Day
Low-power systems implemented on Field Programmable Gate Arrays (FPGA) have become more practical with advancements leading to decreases in FPGA power consumption, physical size, and cost. In systems that may need to operate for an extended time independent of a central power source, low-power FPGA’s are now a reasonable option. Combined with research into energy harvesting solutions, a FPGA-based system could operate independently indefinitely and be cost effective. Four simple demodulator designs were implemented on a FPGA to test and compare the performance and power consumption of each. The demodulators were a Counter that tracked the length of the input signal period, a One-Shot that counted the input edges over time, a Phase-Frequency Detector (PFD), and a PFD with preprocessing on the input signal to mitigate distortion introduces by the 1-bit subsampling. The designs demodulated a binary frequency shift keying (BFSK) signal using 10.69MHz and 10.71MHz as the input frequencies and a 1kHz data rate. The signal was 1-bit subsampled at 75kHz to provide the demodulators with a signal containing 15kHz and 35kHz. The design size, power consumption, and error performance of each demodulator were compared. At the frequencies and data rate used, the Counter and One-Shot are the most energy efficient by a significant margin over the PFDs. The error performance was nearly equal for all four. As the BFSK baseband frequencies and especially the data rate are increased, the PFD options are expected to be the better options as the Counter and One-Shot may not react quickly enough.
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Sunkara, Sudhir Kumar. "PERFORMANCE OF COHERENT DIRECT SEQUENCE SPREAD SPECTRUM FREQUENCY SHIFT KEYING." Ohio University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1133385679.
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Ghuman, Parminder, Salman Sheikh, Steve Koubek, Scott Hoy, and Andrew Gray. "High Rate Digital Demodulator ASIC." International Foundation for Telemetering, 1998. http://hdl.handle.net/10150/609676.
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International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, CaliforniaThe architecture of the High Rate (600 Mega-bits per second) Digital Demodulator (HRDD) ASIC capable of demodulating BPSK and QPSK modulated data is presented in this paper. The advantages of all-digital processing include increased flexibility and reliability with reduced reproduction costs. Conventional serial digital processing would require high processing rates necessitating a hardware implementation other than CMOS technology such as Gallium Arsenide (GaAs) which has high cost and power requirements. It is more desirable to use CMOS technology with its lower power requirements and higher gate density. However, digital demodulation of high data rates in CMOS requires parallel algorithms to process the sampled data at a rate lower than the data rate. The parallel processing algorithms described here were developed jointly by NASA’s Goddard Space Flight Center (GSFC) and the Jet Propulsion Laboratory (JPL). The resulting all-digital receiver has the capability to demodulate BPSK, QPSK, OQPSK, and DQPSK at data rates in excess of 300 Mega-bits per second (Mbps) per channel. This paper will provide an overview of the parallel architecture and features of the HRDR ASIC. In addition, this paper will provide an overview of the implementation of the hardware architectures used to create flexibility over conventional high rate analog or hybrid receivers. This flexibility includes a wide range of data rates, modulation schemes, and operating environments. In conclusion it will be shown how this high rate digital demodulator can be used with an off-the-shelf A/D and a flexible analog front end, both of which are numerically computer controlled, to produce a very flexible, low cost high rate digital receiver.
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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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Simms, Dennis, and Kurt Kosbar. "IMPROVEMENTS IN AUTOMATIC MODULATION RECOGNITION OF ASK AND FSK SIGNALS." International Foundation for Telemetering, 2000. http://hdl.handle.net/10150/608248.
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International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, CaliforniaAn algorithm for automatic modulation recognition of ASK, PSK and FSK was developed by Azzouz and Nandi. The algorithm has some serious problems at SNR of 10 dB and below. This paper describes a modification to the algorithm that significantly improves the performance for detection of ASK and FSK at moderate and low SNR.
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Gibbs, Jonathan Alastair. "Techniques for the synchronisation and demodulation of fast frequency hopped M-ary frequency shift keying." Thesis, University of Southampton, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293202.
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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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Chiu, Frank Kwok King. "Data communications using coherent minimum frequency shift keying on intrabuilding polyphase power line networks." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/26225.
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The suitability of Coherent Minimum Frequency Shift Keying (CMFSK) modulation for data communications on polyphase intrabuilding power distribution circuits is examined. An actual modem was designed and implemented. Average bit error rate (BER) versus received Eb/No measurements were taken for an industrial, commercial, and residential power line environments at 1.2kbps, 4.8kbps, and 19.2kbps data rate.
The 19.2kbps BER measurements indicate that a majority of errors are caused by impulses occurring in the power lines, while other errors are caused by momentary reductions of received Eb/No. Occurance of errors coincides mostly with impulses on the power line which are highly periodic with the ac mains voltage. In addition, the BER measurements reveal that CMFSK modulation at 1.2kbps and 4.8kbps data rate is less affected by impulse noise than at 19.2kbps. This finding is attributed to the increased resistance to impulse noise effects as the bit duration is increased.
A baseband spectrum spreading technique is proposed and successfully tested to implement low data rate transmissions. Spread spectrum signalling overcomes potential narrow band impairments by sending a wide1 band signal over the power lines. In addition, the reduced power spectral density of the spread spectrum transmission reduces narrow band interference to other power line communications users as well as AM radios and allows higher output power to compensate for path attenuations.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
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Kocakanat, Murat. "A direct sequence - code division multiple access/binary phase shift keying (DS-CDMA/BPSK) modem design." Monterey, California. Naval Postgraduate School, 1997. http://hdl.handle.net/10945/8270.
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Spyridis, Konstantinos. "Hybrid hard and soft decision decoding of Reed-Solomon codes for M-ARY frequency-shift keying." Thesis, Monterey, California : Naval Postgraduate School, 2010. http://edocs.nps.edu/npspubs/scholarly/theses/2010/Jun/10Jun%5FSpyridis.pdf.
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Thesis (Electrical Engineer and M.S. in Electrical Engineering)--Naval Postgraduate School, June 2010.Thesis Advisor(s): Robertson, R. Clark; Second Reader: Kragh, Frank; Cristi, Roberto. "June 2010." Description based on title screen as viewed on July 14, 2010. Author(s) subject terms: Hybrid Reed-Solomon (RS) coding, Orthogonal signaling, Additive White Gaussian Noise (AWGN), Pulse-Noise Interference (PNI), coherent detection, noncoherent detection. Includes bibliographical references (p. 101-103). Also available in print.
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Castaneda, Francisco Jose. "Comparison of complementary sequences in hybrid phase and frequency shift keying CW radar using periodic ambiguity analysis." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/27805.
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Continuous waveform (CW) polyphase sequences for radar have a much lower power spectral density (PSD) than pulsed signals but can retain the same target detection capability. The use of different phase values or subcodes to modulate the carrier provides a low probability of intercept (LPI) radar waveform which cannot be seen by a non-cooperative intercept receiver (NCIR). Also, it is a low probability of detection (LPD) waveform due to the low PSD. Frequency shift keying (FSK) radar has a higher PSD but is moved about quickly in frequency over a large bandwidth in which the NCIR cannot follow. Consequently, the FSK (usually a Costas frequency set) remains a LPI signal but not a LPD. To combine the advantages of each waveform, this thesis presents a hybrid FSK/PSK emitter waveform to further the LPI, LPD characteristics. By combining both techniques (PSK/FSK), a high time-bandwidth waveform is constructed that provides better LPI/LPD characteristics than each waveform. The periodic ambiguity function (PAF) is evaluated for three different complementary sequences to modulate a Costas frequency set. The peak time and Doppler sidelobes of the PAF are compared against the P4 polyphase modulation for the Golay complementary sequence (15 dB improvement), the quaternary periodic complementary sequence (16 dB improvement), and the quaternary Golay complementary sequence (18 dB improvement).
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Campbell, Robert F. "Analysis of Various Algorithmic approaches to Software-Based 1200 Baud Audio Frequency Shift Keying Demodulation for APRS." DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1634.
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Digital communications continues to be a relevant Field of study as new technologies appear and old methodologies get revisited or renovated. The goal of this research is to look into the old digital communication scheme of Bell 202 [67] used by APRS and improve software based demodulation performance. Improved performance is defined by being able to correctly decode more packets in an efficient, real time, manner. Most APRS demodulation is currently done using specialized hardware since that yields the best performance. This research shows that through using Sivan Toledo's javAX25 [72] software package, new demodulation algorithms can be implemented that decode more Bell 202 encoded AX.25 packets than the existing software could. These improvements may help drive the adoption of software demodulation since it is a low cost alternative to specialized hardware.
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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, CaliforniaPresentation 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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Voskakis, Konstantinos. "Modeling and simulation of a non-coherent frequency shift keying transceiver using a Field Programmable Gate Array (FPGA)." Thesis, Monterey, Calif. : Naval Postgraduate School, 2008. http://edocs.nps.edu/npspubs/scholarly/theses/2008/Sept/08Sep%5FVoskakis.pdf.
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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, September 2008.Thesis Advisor(s): Kragh, Frank ; Ateshian, Peter. "September 2008." Description based on title screen as viewed on November 4, 2008. Includes bibliographical references (p. 97-103). Also available in print.
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Spáčil, Jan. "Komunikační systémy s digitálními modulacemi." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217453.
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The purpose of this semestral project is to explain the basic issues of simple digital modulations through the creation of simple digital modulations using direct digital synthesis. It begins with a short review of digital modulation theory and the theory about direct digital synthesis. All the technical documentation is attached, including schematics and boards of functional modulator.
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Berhanu, Samuel, and Kamal Neupane. "Digital Radio Implementation for NASA S-Band Space Network Transceiver." International Foundation for Telemetering, 2012. http://hdl.handle.net/10150/581843.
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The system diagrams for the digital radio compatible with NASA's S-Band Space Network operating from 2025.8 - 2117.9 MHz (forward link) to 2200 - 2300 MHz (return link) are presented. The digital radio implementation includes binary phase shift keying (BPSK), quadrature phase shift keying (QPSK) and staggered quadrature phase shift keying (SQPSK). We have derived the system requirements for these modulation schemes from the Space Network User Guide (SNUG) and thereafter, derived system diagrams for the communication links. The designed system diagrams for the transceiver were implemented using Simulink models and USRP2 platform.
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Al-Sharari, Hamed. "An implementation of acquisition using transform domain/cycle code shift keying system on a multipath channel." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1177004799.
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Hunter, Richard E. Jr. "HIGH ALPHABET FLIGHT TERMINATION SYSTEM." International Foundation for Telemetering, 2001. http://hdl.handle.net/10150/607664.
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International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, NevadaThis paper proposes a modification of the high alphabet method of data transmission over an RF carrier. The system maps eleven characters into three tones. The three tones are Frequency Modulated onto an RF carrier. The 165 unique characters can be utilized for data transmission. The advantages of this system are: 1. Longer duration data words which have narrow bandwidth yielding a high signal to noise ratio. 2. Digital Signal Processing can be utilized to reconstruct characters from the tri-tone encoding. 3. The system will be less susceptible to external interference than normal Frequency Shift Keying system. The majority of the three tone burst would have to masked in order to loose a data word.
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Shaw, Christopher. "Synchronization for Burst-Mode APSK." International Foundation for Telemetering, 2009. http://hdl.handle.net/10150/606120.
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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, NevadaWe derive bounds on the performance of data-aided joint estimators for timing offset, carrier phase offset, and carrier frequency offset for use in an APSK packet-based communication link. It is shown that the Cramér-Rao Bound (CRB) is a function of the training sequence, the signal-to-noise ratio (SNR), and the pulse shape. We also compute APSK training sequences of different lengths that minimize the CRB for each of the parameters.
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Aflatouni, Katayoun, and Kamilo Feher. "SMART DIVERSITY RECEIVERS FOR DYNAMIC, MULTIPATH, FREQUENCY SELECTIVE FADED FQPSK AND OTHER SYSTEMS." International Foundation for Telemetering, 2001. http://hdl.handle.net/10150/606440.
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International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, NevadaDesign, performance Test and Evaluation (T&E) of a novel smart diversity receiver, based on Feher Diversity (FD) patents over multipath, fast dynamic frequency selective fading channels is presented. A hardware simulator for construction of a frequency selective fading channel has been implemented in laboratory to resemble a telemetry aeronautical channel model, namely the two-path channel model. As an illustrative example, the block error rate (BLER) of a 1 Mb/s rate IRIG 106-00 and CCSDS standardized Feher’s patented quadrature phase shift keying (FQPSK) [1][2] with and without diversity in multipath frequency selective fading channels has been tested and evaluated. The experimental results clearly indicate significant performance improvement with the proposed diversity technique even in cases of severely distorted channels.
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Potter, Chris, Kurt Kosbar, and Adam Panagos. "Effects of Synchronization Error on Space Time Block Codes Equipped with FSK Waveforms." International Foundation for Telemetering, 2009. http://hdl.handle.net/10150/605966.
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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, NevadaSpace-time Coding (STC) for Multiple-Input Multiple-Output (MIMO) wireless communication systems is an effective technique for providing robust wireless link performance in telemetry systems. This paper investigates the degradation in system performance when synchronization errors between the transmitter and receiver are present. Specifically, expressions that quantify the increase in symbol-error-rate as a function of symbol synchronization error are derived for a two-transmit and single receive antenna MISO system using binary frequency shift keying waveforms. These results are then extended to the MIMO case. The analytic results are verified with simulation results that show close agreement between the theoretical expressions and Monte Carlo simulation runs.
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Gray, Andrew, Meera Srinivasan, Marvin Simon, and Tsun-Yee Yan. "FLEXIBLE ALL-DIGITAL RECEIVER FOR BANDWIDTH EFFICIENT MODULATIONS." International Foundation for Telemetering, 1999. http://hdl.handle.net/10150/608745.
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International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, NevadaAn all-digital high data rate parallel receiver architecture developed jointly by Goddard Space Flight Center and the Jet Propulsion Laboratory is pre- sented. This receiver utilizes only a small number of high speed components along with a majority of lower speed components operating in a parallel fre- quency domain structure implementable in CMOS, and can process over 600 Mbps with numerous varieties of QPSK modulation, including those incorpo- rating precise pulse shaping for bandwidth eÆcient modulation. Performance results for this receiver for bandwidth eÆcient QPSK modulation schemes such as square-root raised cosine pulse shaped QPSK and Feher’s patented QPSK are presented, demonstrating the great degree of exibility and high performance of the receiver architecture.
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McCulley, Scott L. "Design and Implementation of a Practical FLEX Paging Decoder." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/35557.
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The Motorola Inc. paging protocol FLEX is discussed. The design and construction of a FLEX paging protocol decoder is discussed in detail. It proposes a decoding solution that includes a radio frequency (RF) receiver and a decoder board. The RF receiver will be briefly discussed.
The decoder design is the main focus of this thesis as it transforms the RF frequency modulated (FM) data from the receiver and converts it to FLEX data words. The decoder is designed to handle bit sampling, bit clock synchronization, FLEX packet detection, and FLEX data word collection. The FLEX data words are then sent by the decoder to an external computer through a serial link for bit processing and storage. A FLEX transmitter will send randomly generated data so that a bit error rate (BER) calculation can be made at a PC. Each receiver'9s noise power and noise bandwidth will be measured so that noise spectral density may be calculated. A complete measurement set-up will be shown on how these noise measurements are made. The BER at a known power level is recorded. This enables Eb/No curves to be generated so that results of the decoding algorithm may be compared. This is performed on two different receivers.Master of Science
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Law, Eugene, and Kamilo Feher. "FQPSK VERSUS PCM/FM FOR AERONAUTICAL TELEMETRY APPLICATIONS; SPECTRAL OCCUPANCY AND BIT ERROR PROBABILITY COMPARISONS." International Foundation for Telemetering, 1997. http://hdl.handle.net/10150/609732.
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International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, NevadaThe aeronautical telemetry community is investigating alternative modulation methods to the commonly used non-return-to-zero (NRZ) pulse code modulation (PCM)/frequency modulation (FM). This paper outlines the important characteristics being investigated. Measured data comparing the spectral occupancy and bit error probability (BEP) performance of PCM/FM with that of a prototype constant envelope Feher’s quadrature phase shift keying (FQPSK) modulator and demodulator will also be presented. Measured results in several radio frequency bands demonstrate that the 99.99% and -60 dBc bandwidths of filtered FQPSK are only approximately one-half of the corresponding bandwidths of optimized PCM/FM even when the signal is non-linearly amplified. The signal energy per bit to noise power spectral density (E /N ) required for a BEP of 1×10 b 0 -5 for non-optimized FQPSK was approximately 12 dB which is approximately the same as limiter discriminator detected PCM/FM.
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Du, Preez Johannes. "An investigation into OFDM as a suitable modulation tecnique for an acoustic underwater modem." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71806.
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Thesis (MScEng)--Stellenbosch University, 2012.ENGLISH ABSTRACT: This thesis investigates orthogonal frequency division multiplexing (OFDM) as a viable modulation technique for an ultrasonic acoustic underwater modem. The underwater environment provides a challenging setting for acoustic communications. Long delay spreads due to multipath propagation, severe Doppler frequency shifts, frequency dependent absorption and very limited bandwidth are but some of the challenges to overcome. OFDM essentially provides the parallel transmission of symbols in the frequency domain by simultaneously modulating many closely spaced orthogonal subcarriers. The resulting long parallel symbol rate together with the cyclic extension of symbols render the signal robust against intersymbol interference (ISI) caused by multipath propagation. Intercarrier interference (ICI) between the overlapping frequency responses of subcarriers is mitigated by their property of orthogonality. Doppler spread contributes to the loss of orthogonality and can result in severe ICI. A method of measuring the Doppler shift by means of including a preamble and postamble symbol with each data frame is proposed. The detected frequency offset is corrected by resampling the frame at the desired sample rate. Not only do the ambles serve as a mechanism for timing and frequency synchronisation, but they are also applied in the channel estimation process. The equalisation of channel response is required for the coherent demodulation of the received symbols. An investigation into different phase shift keying (PSK) and quadrature amplitude modulation (QAM) constellations reveal optimal arrangements for minimal symbol errors. The optimised QAM constellations do not lend themselves to Gray-coding, so that an efficient interleaving scheme is needed to mitigate the non-uniform distribution of bit errors among symbol errors. Forward error correction is provided via a Bose Chaudhuri Hocquenghem (BCH) block code. Variable code rates, together with the ability to switch between different constellations, enable the modem to perform so-called variable modulation in an attempt to maximise the throughput under specific channel conditions. The modulation/demodulation scheme is wholly defined in software as to provide flexibility and facilitate experimentation with different signal processing methods. The accompanying hardware platform allows for the transmission of a pre-generated signal and the recording of a received signal for off-line processing. The prototype design serves as a proof of concept and thus provides only simplex communication. Field tests over limited distances demonstrate the successful operation of the prototype modem. We conclude that OFDM is indeed a suitable modulation technique for acoustic underwater communication.
AFRIKAANSE OPSOMMING: Hierdie tesis ondersoek die toepassing van ortogonale frekwensiedeling multipleksering (OFDM) as modulasie tegniek op ʼn onderwater kommunikasie modem. Die onderwater omgewing bied vele uitdagings vir akoestiese kommunikasie. Lang vertraging-verstrooiings as gevolg van multipad voortplanting, Doppler frekwensieskuif, frekwensieafhanklike absorpsie, en beperkte bandwydte is van die uitdagings wat oorkom moet word. In essensie bied OFDM die parallelle versending van ʼn aantal simbole deur die gelyktydige modulasie van verskeie nou-gespasieerde subdraers in die frekwensiegebied. Die gevolglike lang parallelle simboolperiodes, tesame met die sikliese uitbreiding van simbole, verleen immuniteit teen intersimbool steurnisse (ISI) wat ontstaan as gevolg van multipad voortplanting. Die ortogonaliteit van naburige draers in die frekwensiegebied beperk interdraer steuring (ICI) tussen hul oorvleuelende frekwensie weergawes. Doppler frekwensieskuif kan egter lei tot die verlies aan ortogonaliteit en bydra tot ernstige interdraer steurings. ʼn Metode wat gebruik maak van aanhef en slot simbole, ingesluit by elke raam, word voorgestel om die Dopplerskuif te meet. Die bepaalde frekwensieafset word gekorrigeer deur die monstertempo van die raam aan te pas na die verlangde tempo. Buiten die tyd- en frekwensie-sinkronisasie funksies van die aanhef en slot simbole, speel dit ook ʼn belangrike rol in die ontrekking van die frekwensie weergawe van die kanaal. Die effening van die kanaal se frekwensieweergawe is noodsaaklik vir die koherente demodulasie van die ontvangde simbole. ʼn Ondersoek na verskillende fase verskuif sleuteling (PSK) en kwadratuur amplitude modulasie (QAM) konstellasies het optimale rangskikkings opgelewer vir minimale simboolfoute. Hierdie optimale QAM konstellasies verleen hulself egter nie na Gray-kodering nie. ʼn Effektiewe invlegtegniek is nodig om die nie-uniforme verspreiding van bisfoute tussen simboolfoute te beperk. Fout korrigering funksionaliteit word gebied deur ʼn Bose Chaudhuri Hocquenghem (BCH) blokkode. Verstelbare koderingstempo’s en die vermoë om tussen verskillende konstellasies te skakel, stel die modem in staat om sogenaamde verstelbare modulasie te gebruik in ʼn poging om die data deurset te optimeer onder spesifieke kanaal kondisies. Die modulasie en demodulasie skema is volledig in sagteware gedefinieer. Dit verleen buigbaarheid en vergemaklik eksperimentering met verskeie seinverwerkingstegnieke. Die meegaande hardeware platvorm stel die modem in staat om vooraf opgewekte seine uit te saai en rou ontvangde siene op te neem vir na-tydse verwerking. Die prototipe ontwerp dien as ʼn konseptuele bewys en bied dus slegs simplekse kommunikasie. Die suksesvolle werking van die modem is gedemonstreer deur toetsing oor beperkte afstande. Hieruit word afgelei dat OFDM inderdaad geskik is vir akoestiese onderwater kommunikasie.
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Dudal, Clément. "Forme d'onde multiporteuse pour de la diffusion par satellite haute capacité." Phd thesis, Toulouse, INPT, 2012. http://oatao.univ-toulouse.fr/8342/1/dudal.pdf.
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Cette thèse se concentre sur l’amélioration conjointe de l'efficacité spectrale et de l'efficacité en puissance de schémas de transmission par satellite. L’émergence de nouveaux services et l'augmentation du nombre d’acteurs dans le domaine nécessitent de disposer de débits de plus en plus importants avec des ressources de plus en plus limitées. Les progrès réalisés ces dernières années sur la technologie embarquée et dans le domaine des communications numériques permettent de considérer des schémas de transmission à plus haute efficacité spectrale et en puissance. Cependant, l’enjeu majeur des schémas de transmission proposes actuellement reste de rentabiliser les ressources disponibles. L’étude développée dans cette thèse explore les possibilités d’amélioration conjointe de l’efficacité spectrale et de l’efficacité en puissance en proposant la combinaison de la modulation Cyclic Code-Shift-Keying (CCSK), dont l’efficacité en puissance augmente avec l’élévation du degré de la modulation, avec une technique de multiplexage par codage de type Code-Division Multiplexing (CDM) pour pallier la dégradation de l’efficacité spectrale liée à l’étalement du spectre induit par la modulation CCSK. Deux approches basées sur l’utilisation de séquences de Gold de longueur N sont définies: Une approche multi-flux avec un décodeur sphérique optimal en réception. La complexité liée à l’optimalité du décodeur conduit à des valeurs d'efficacité spectrale limitées mais l’étude analytique des performances, vérifiée par des simulations, montre une augmentation de l'efficacité en puissance avec l'efficacité spectrale. Une approche mono-flux justifiée par l’apparition de redondance dans les motifs résultant du multiplexage des séquences. L’approche mono-flux propose des valeurs d’efficacité spectrale équivalente aux schémas retenus dans le standard DVB-S2 avec une amélioration de l’efficacité en puissance à partir d’un certain seuil de rapport signal à bruit par rapport à ces schémas. Par la suite, l'étude porte sur la transposition de plusieurs symboles de modulation sur les porteuses d’un système OFDM et sur les bénéfices et avantages d’une telle approche. Elle se conclut sur l’apport d’un codage canal basé sur des codes par bloc non binaires Reed-Solomon et LDPC. La forme d’onde proposée offre des points de fonctionnement à haute efficacité spectrale et haute efficacité en puissance avec des perspectives intéressantes. Dans le contexte actuel, son application reste limitée par ses fluctuations d’amplitude mais est envisageable dans un contexte de transmission multiporteuse, comme attendu dans les années à venir.
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Kerbal, Sofiane. "Development of new criteria for train detection and evaluation in critical conditions." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-253201.
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Railway signaling is of paramount importance to ensure traffic management andsafety on the rail network. The main lines are divided into sections called ‘blocks’,which are governed by a fixed signal installation. To prevent trains from colliding,each block allows one train at once. In France (and most European countries),train detection is performed by an electrical device called track circuit that consistsof a transmitter and a receiver installed at the track-side, and connected via therails. In the absence of a train, an electrical signal flows from the transmitter tothe receiver through the rails. As a train enters a track circuit, its axles shuntthe rails, provoking a short circuit (also called ‘shunt’): the signal transmitted tothe receiver drops. The detection of that signal drop results in the detection of atrain. This method rarely fails throughout the network, but there can be criticalcases where it may be inefficient. In this Master’s Thesis, new detection criteriaproposed in previous studies have been tested on signals measured in poor shuntingconditions. Three approaches have been tested: one in the time domain and two inthe frequency domain. The time approach compares the short-term and long-termstatistics of the received signals. The observation of a change in the spectra of thereceived signals around the 3rd order harmonic (3OH) has led to the implementationof two frequency criteria: the estimation of the band power around the 3OH andthe detection of the 3OH peaks. The obtained results show that better detection isachieved when the new criteria and the existing one are combined.Tågsignalsystem är väsentliga för att garantera trafikstyrning och säkerhet i tågnätet.Spåren är indelade i sektioner, s.k. block, som övervakas med fasta signalinstallationer.För att hindra tåg från att krocka, tillåts bara ett tåg i taget per block. IFrankrike (och de flesta andra europeiska länder), detekteras tågen med en elektriskspårkrets som består av en sändare och en mottagare som är installerad bredvidspåret och ansluten till rälsen. När inget tåg finns på spåret, flyter en elektrisk signalfrån sändaren till mottagaren via spåret. När ett tåg anländer, kortsluts kretsenav hjulaxeln och signalen försvinner från mottagaren. Minskningen i signalstyrkaanvänds för att detektera tåget. Denna metod sällan misslyckas i tågnätet, men iovanliga fall kan det uppstå farliga situationer. I detta examensarbete utvärderasnya detektionsmetoder, som har föreslagits i tidigare studier, på signaler som haruppmätts under förhållanden med dålig kontakt mellan hjul och spår. Tre olika metoderhar testats, en i tidsdomänen och två i frekvensdomänen. Tidsdomänsmetodenjämför kortvarig och långvarig statistik för den mottagna signalen. I spektrum förden mottagna signalen, har man observerat en förändring runt den tredje övertonen,samt detektering av frekvenstoppar vid tredje övertonen. De erhållna resultatenvisar på förbättrad detektering när de nya och existerande kriterierna kombineras.
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Purbawati, Anike. "Modulation de la fréquence d'un oscillateur spintronique (STNO) pour des applications de communication sans fil." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY023/document.
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Les Oscillateurs Spintronique (STNO) sont un nouveau type d'oscillateurs à fréquence radio (RF) qui utilisent l'effet « Spin Transfer Torque (STT) » dans un dispositif de jonction tunnel magnétique (MTJ) pour produire des oscillations entretenues à haute fréquence. Les STNO fournissent des solutions compactes pour la communication sans fil utilisées dans « wireless sensor network (WSN) » car leur fréquence peut être réglée via un courant continu. Ce réglage de fréquence permet de coder l'information via « Frequency shift keying (FSK) » par modulation numérique entre deux valeurs discrètes sans besoin d'un RF mixer, ce qui conduit à des composants RF potentiellement moins complexes. Dans cette thèse, la faisabilité de FSK a été étudiée pour des STNO MTJ à aimantation dans le plan en vue des communications sans fil utilisées dans les WSN. Les paramètres abordés dans cette étude sont le décalage de fréquence et le taux de modulation maximum, auquel la fréquence peut être décalée entre deux valeurs discrètes.Pour caractériser le taux de modulation maximum, des simulations macrospin et des études expérimentales ont été réalisées. Les simulations révèlent que le taux de modulation maximum pour FSK par courant est limité par la fréquence de relaxation du STNO, qui est de l'ordre de quelques centaines de MHz pour les STNO à aimantation dans le plan. Cela signifie que le taux de modulation maximum est limité à quelques centaines de Mbps, ce qui est ciblé ici pour une communication sans fil à débit de données modéré utilisées dans les WSN. Des études expérimentales du FSK par modulation de courant dans les STNO ont été effectuées pour des STNO autonomes et pour des STNO intégrés dans des systèmes hyperfréquences. Le FSK sur les STNO autonomes montre un décalage de fréquence autour de 200 MHz (le décalage de fréquence entre ≈ 8,9 GHz et ≈9,1 GHz) au taux de modulation de 10Mbps. Ce taux de modulation est inférieur à la limite supérieure donnée par la fréquence de relaxation du STNO comme prévu dans la simulation numérique en raison du bruit de phase relativement élevé du dispositif mesuré. Afin de tester la faisabilité du STNO dans les systèmes hyperfréquences, la modulation FSK des STNO a été effectuée sur un émetteur de carte de circuit imprimé (PCB). L'émetteur de PCB a été réalisé et développé par le partenaire du projet Mosaic FP7, TUD University. L'analyse confirme qu'un changement de fréquence autour de 300 MHz (le décalage de fréquence entre ≈9 GHz et ≈9,3 GHz) a été observé avec un taux de modulation de 20 Mbps. Le taux de données est limité par les caractéristiques de l'émetteur de PCB et non intrinsèque au STNO. Les études de simulation et d'expérience de la modulation de fréquence des STNO démontrent que le débit de données est adéquat pour la communication sans fil utilisée dans WSN.Cependant, d'autres améliorations dans les matériaux et la nanofabrication de STNO sont nécessaires pour améliorer la puissance de sortie et améliorer les caractéristiques spectrales des oscillations pour pousser les débits de données à des valeurs plus élevées avec un grand décalage de fréquenceSpin Transfer Nano-Oscillators (STNOs) are a novel type of Radio Frequency (RF) oscillators that make use of the Spin Transfer Torque (STT) effect in a magnetic tunnel junction (MTJ) device to produce high-frequency auto-oscillations. STNOs are attractive for applications in wireless communications due to their nanometric size and their frequency tuning capabilities via either a dc current or an applied field. This frequency tuning permits to encode the information via frequency shift keying (FSK) by digital modulation of the current or applied field between two discrete values without the need of an external RF mixer, leading to potentially less complex RF components. In this thesis, the feasibility of the digital frequency modulation (frequency shift keying (FSK)) using in-plane magnetized MTJ STNOs has been studied. For this, the maximum modulation rate, up to which a signal can be modulated or the frequency can be shifted between two discrete values, is an important aspect that need to be characterized.The characterization of the maximum modulation rate for in-plane magnetized MTJ STNOs has been studied via numerical macrospin simulation for different modulation configurations, i.e. modulation by a sinusoidal RF current and a sinusoidal RF field. It revealed that the maximum modulation rate under RF current modulation is given by the amplitude relaxation frequency fp of the STNO. Under RF field modulation, i.e. an RF field applied parallel to the easy axis, an enhanced modulation rate above fp can be achieved since the frequency is modulated directly via the field and not via the amplitude. This suggests an important strategy for the design of STNO-based wireless communications and to achieve high data rates. Besides numerical simulation, experimental studies of frequency shift keying (FSK) by current modulation in STNOs have been also demonstrated. The first demonstration is the FSK in standalone STNOs. The analysis confirmed that the FSK was successfully observed with a frequency shift around 200MHz (the frequency shift between ≈8.9 GHz and ≈9.1 GHz) at the modulation rate of 10Mbps. This modulation rate is however less than the upper limit, which is given by the relaxation frequency fp of the STNO as predicted in the numerical simulation, because of the relatively high phase noise of the device measured. In order to test the feasibility of the STNO within microwave systems, the FSK modulation of STNOs was performed on a printed circuit board (PCB) emitter. FSK with a frequency shift around 300MHz (the frequency shift between ≈9 GHz and ≈9.3 GHz) was observed with a modulation rate of 20 Mbps. The data rate here was limited by characteristics of the PCB emitter and not intrinsic to the STNO. The simulation and experiment studies of frequency modulation of STNOs demonstrate that the data rate of is adequate for wireless communication used in WSN. However, further improvements in materials and nanofabrication of STNOs are required to enhance the output power and improve the spectral characteristics of the oscillations to push the data rates to higher values with large frequency shift
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Naab-Levy, Adam O. "Enhanced Distance Measuring Equipment Data Broadcast Design, Analysis, Implementation, and Flight-Test Validation." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1449158180.
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Le, Van-Hoan. "Analyses de microvolumes de gaz par spectroscopie Raman : expériences quantitatives et modélisation des mélanges CO₂-CH₄-N₂." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0178.
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Les inclusions fluides naturelles peuvent fournir des informations quantitatives précieuses pour reconstruire les conditions de circulation des paléofluides. CO₂, CH₄ et N₂ sont les espèces gazeuses majoritaires le plus souvent rencontrées dans divers environnements géologiques. Cependant les données d’étalonnage des mélanges constitués de ces espèces pour une quantification de leurs propriétés PVX ne sont pas encore complètement établies. L'utilisation des données de calibration disponible dans la littérature peut donc entraîner des erreurs significatives. L'objectif central de ce travail de thèse est d’apporter des données d’étalonnage du signal Raman des gaz CO₂, CH₄, N₂ et de leurs mélanges, sur une gamme de pression de 5 à 600 bars, afin de pouvoir déterminer simultanément les propriétés PVX à une température fixée. Pour cela, des mélanges de gaz ont été préparés à haute pression par le biais d'un mélangeur (GasMix AlyTech) couplé avec un système de pressurisation développé au laboratoire GeoRessources. Des analyses in situ Raman des mélanges de gaz ont été réalisées dans des conditions contrôlées en utilisant le système HPOC couplé avec un microcapillaire transparent placé sur une platine microthermométrique (Linkam CAP500). L’incertitude des mesures des propriétés PVX à 22 ou 32 °C à partir de nos équations d’étalonnage est de < 1 mol%, ~ ± 20 bars et ~ ± 0,02 g.cm-³ pour la composition, la pression et la densité, respectivement. Un autre objectif du projet est d'interpréter la tendance de variation de la position du pic du N₂ et/ou CH₄ pour une compréhension approfondie. Deux modèles théoriques, i.e., le potentiel de Lennard-Jones 6-12 et le modèle « Perturbed hard-sphere fluid » ont été utilisés pour évaluer quantitativement la contribution des forces d'interaction intermoléculaire attractives et répulsives aux décalages des bandes de CH₄ et N₂. Un modèle prédictif a été proposé pour prédire la tendance de la variation de la position du pic du CH₄ jusqu'à 3000 bars en fonction de la pression et de la composition. En fin, l'applicabilité de nos données d'étalonnage aux autres systèmes gazeux ou dans d’autres laboratoires est discutée et évaluée. Des nouvelles données d’étalonnage universelles applicables dans d’autres laboratoires sont fournies. Un programme de calcul « FRAnCIs » avec une interface utilisateur a été développé pour rendre l'utilisation de nos données d'étalonnage accessibles au plus grand nombreQuantitative knowledge of species trapped within fluid inclusions provides key information to better understand geological processes as well as to reconstruct the conditions of paleofluid circulation. CO₂, CH₄, and N₂ are among the most dominant gas species omnipresent in various geological environments, but their quantitative PVX calibration data are not fully established yet. Using the previously published data can therefore lead to non-quantified errors, especially when applied to geological fluids containing generally several substances at elevated pressure and density. The aim of this work is to provide accurate calibration data for the simultaneous determination of PVX properties of pure gases or any binary and ternary mixtures of CO₂, CH₄, and N₂ over 5 to 600 bars at a fixed temperature, directly from Raman spectra. For this, gas mixtures were prepared and compressed using a mixer (GasMix AlyTech) coupled with a homemade pressurization system. Raman in situ analyses of gas mixtures were performed at controlled conditions using an improved HPOC system (High-Pressure Optical Cell) with a transparent microcapillary containing the prepared gas mixtures, placed on a heating-cooling stage (Linkam CAP500). Overall, the uncertainty of the measurement of the PVX properties of fluid inclusions from our calibration equations at 22 or 32 °C is < ± 1 mol%, ~ ± 20 bars, and ~ ± 0.02 g.cm-³ for molar proportion, pressure and density, respectively. The ensuing aim of the project is to interpret the variation trends of the peak position of the CH₄ and N₂ ν1 band for an in-depth understanding. Two theoretical models, i.e., Lennard-Jones 6-12 potential energy approximation and Perturbed hard-sphere fluid model were involved to quantitatively assess the contribution of the attractive and repulsive intermolecular interaction forces to the pressure-induced frequency shifts. A predictive model was also provided to predict the variation trend of the CH₄ ν1 band over a pressure range up to 3000 bars as a function of pressure and composition. Furthermore, the applicability of our calibration data to other laboratories and apparatus and to gas mixtures that contain a small amount of other species (e.g., H2, H2S) was discussed and evaluated. New universal calibration data applicable for other laboratories were then provided. A computer program “FRAnCIs” was also developed to make the application of our calibration data as convenient as possible via a user-friendly interface
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Kao, Yu-Han, and 高郁函. "Ultrasonic Communication by Applying Binary Frequency Shift Keying to Piezoelectric Transducers." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/53860545221026304542.
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碩士國立臺灣大學
工程科學及海洋工程學研究所
103
In recent years, security, comfort and convenience driving experience have become increasingly important. This trend as well as issues of energy saving and environmental protection, result in the popularity of intelligent vehicles with vehicular ad-hoc network. The vehicle manufacturers install transducers, radars and cameras on intelligent vehicles, which operate many functions such as safety system, auto-driving system, and instantaneous navigation. Vehicular ad-hoc network includes several different ways of communication. For example, parking sensors apply ultrasonic communication. The advantage of acoustic communication system is low cost, high system compatibility, less influence on human health compared to radio waves. As a result, such system has increasing importance in the technique of short-distance data transmission. If we combine the acoustic communication system with other wireless communication systems via radio waves, the problem of narrow band can be solved, and a good communication quality can be achieved. The purpose of this research is to establish a communication system that not only detects the signals but also has the ability to transmit information. The system applies binary frequency shift keying to piezoelectric transducers. In the future, we can integrate it in vehicular ad-hoc network system. Once the distance between two adjacent vehicles becomes too short such as getting stuck in a traffic jam or waiting in the queue, vehicles will automatically share the relevant information. For example, vehicles will notify one another when car accidents or breakdowns happened. This research will, first, measure the basic characteristics of ultrasonic piezoelectric transducers and construct the model based on them. In addition, we compare different methods of encoding and decoding so as to ensure the lowest error rate during transmission. Last, we analyze the data error rate of different distances. According to the experiment results, the lower the quality factor of the piezoelectric transducer, the shorter the response time of alternating frequency. Under the circumstance of high bits transmission rate, NRZ-L and filter-type FSK demodulators deliver better performance in the bit error rate. Due to the damping effect of transducers, the bit error rate of first bit and last bit is much higher than that of other bits. Therefore, the data should be encoded via an adequate method to avoid damping effect during transmission. When the distance between two transducers is 30cm, we can achieve 0.19% bit error rate of Chinese characters and 0% of the rate of English words by setting bit duration as 0.15msec. When the distance between two transducers is 45cm, 0% bit error rate of both Chinese characters and English words can be achieved by setting bit duration as 0.2msec. However, if the distance between two transducers is 60cm, we have to set bit duration as 0.43msec to attain 0% bit error rate of both Chinese characters and English words.
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Lan, Wei-Ting, and 藍偉庭. "A Closed-Loop Binary Frequency-Shift-Keying RF Transmitter for Wireless Applications." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/93706666674609909930.
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碩士國立清華大學
電機工程學系
96
This thesis presents the design of a fully digital controlled binary frequency-shift- keying (BFSK) RF transmitter for 2.4 GHz wireless applications. Instead of traditional voltage controlled oscillator (VCO), a digitally controlled oscillator (DCO) with three switched-capacitor arrays adopts as a core of this RF transmitter. There are two digital feedback loops to control the DCO to perform the BFSK transmission. Before data transmitting, the DCO codes for both logic-1 and logic-0 frequencies are generated and stored by a binary-searching digital calibration loop. When data modulating and transmitting, another digital phase-locked loop (PLL) is enabled to cancel the frequency shift induces by long-time operation. The designed transmitter is implemented in TSMC 0.18 μm CMOS process, and the chip area is 1.1 × 1.1 mm2. According to the simulation results, the frequency tuning range is around 2.36 ~ 2.59 GHz. The phase noise is about -110 dBc/Hz at 500 kHz offset frequency. For 250-kHz data-rate transmission, the frequency error is less than 100 kHz. The total power consumption is around 13 mW under 1.8 V power supply.
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Chiang, Ping-Chung, and 蔣秉中. "A 2.4-GHz Fully Digital-Controlled Synthesizer-based Binary Frequency-Shift Keying Transmitter." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/20041694843253305267.
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碩士國立清華大學
電機工程學系
98
This thesis presents a fully digital-controlled binary frequency-shift keying (BFSK) RF transmitter for 2.4-GHz Industrial, Science, and Medical band (ISM-band) applications. Compared with analog-controlled transmitters, this one is much less to the process variation and noise interference. The transmitter control scheme is realized by a successive approximation register (SAR) loop and a digital phase control loop. The former loop is used to calibrate the initial output frequency, and the latter is used to compensate the output frequency drift. By incorporating both loops, fast and accurate data transmission can be achieved. The key block of the transmitter is a digitally controlled oscillator (DCO). Its varactor is composed of two switched-capacitor arrays. Two extra capacitors are added for reduction of the capacitance variation. A gated ripple counter is used to estimate the DCO frequency for the SAR and phase control loops. Before data transmission, the SAR loop generates and stores the oscillation tuning words (OTW) of DCO for logic-0 and 1. During data transmission, the phase control loop is enabled to maintain the DCO frequency close to the desired one. This design is implemented in TSMC 0.18-μm 1P6M CMOS process and its chip area is 1 ?n× 1 mm2. According to measurement results, the oscillation frequency range is 2.327 ~ 2.405 GHz, and the phase noise is below -79.8 dBc/Hz at 1 MHz offset. For 250-kbps data transmission, the frequency error is less than 500 kHz. The total power consumption is around 17.6 mW under 1.8 V power supply.
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Wu, Yeong-Ren, and 吳永仁. "The Design of CMOS Binary Frequency-shift keying (BFSK) Demodulator and its Application on RF Receivers." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/15234483900593572942.
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碩士國立交通大學
電子工程系
88
This thesis described the design of BFSK demodulator which are used in a receiver of wireless communication system. The demodulator included a frequency discriminate circuit, mixer, lowpass filter, differential to single-ended circuit and comparator. Its intermediate frequency is 10.7MHz and data transmission rate is 20K BPS. The architecture of demodulator is noncoherent and frequency discriminated. The intermediate frequency signal used differential input. The intermediate frequency signal input to mixer and frequency discriminate circuit which produce a phase shift. The output of frequency discriminate circuit input to the other input port of mixer. The output signal of mixer include double frequency and modulation signal. The lowpass filter moved the double frequency. The differential to single-ended circuit moved the DC offset voltage then comparator produced the digital level output. The demodulator, which is designed and fabricated by 0.5 Double-Poly-Double-Metal (DPDM) n-well CMOS technology, has been measurement. The power consumption of whole chip is 5.9mW from a single 3.3V supply. The chip area is . The measurement result show data transmission rate is 20K BPS, sensitive is 0.7Vp-p . In the future, to decrease discrete components, to reduce power consumption, to reduce system sensitive and to reduce DC offset voltage at baseband circuit are the important researches.
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Wang, Neng-Li, and 王能立. "Performance Analysis of Dithering Techniques for Binary Frequency Shift Keying and the Design of New Finite Impulse Response Filters." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/g7ykjs.
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碩士國立彰化師範大學
電信工程學研究所
106
In the first topic, we discuss whether dithering technology is effective in binary frequency shift keying (BFSK) modulation. The dithering technology in this topic is adding the appropriate amount of independent random signal on binary frequency shift keying signal in front of the analog-to-digital converter (ADC). We analyze the signal spectrum and performance of the quantized binary frequency-shift keying signal with and without using the dithering technology. We found that out-of-band signal can be effectively reduced after dithering. The price paid is an increase of bit error rate due to more quantization noise. In the second topic, we propose a finite impulse response (FIR) filter design method using cascade techniques. We cascade a number of complementary comb filter as a shaping filter and use the modified window design method to design a prototype filter. Then we cascade the two parts to form the composite filter. The composite filter has a very sharp transition band and a very deep cut-off band. It also has a linear phase response. We also design a flexible software interface for designing the composite filter. Users can follow the instructions to generate a number of different designs. This method can also be used in the design of high-pass and band-pass filters of different filter specifications.
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Yogesh, S. "Power Line For Data Communication : Characterisation And Simulation." Thesis, 1995. http://etd.iisc.ernet.in/handle/2005/2188.
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Kung, Chih-Hau, and 龔執豪. "Frequency Shift Keying (FSK) receiver IC." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/57304104198811634983.
Full textAbstract:
碩士國立交通大學
電子研究所
83
An all-CMOS FSK receiver IC has been designed and tested. It employs the square-law characteristic of CMOS transistors in saturated mode. The mixed-mode IC couples many functional blocks , a few linear voltage-to-current and current-to-voltage converters, one phase splitter for I-Q demodulation, one operational amplifier as an integrator in the phase-locked loop, a limiting amplifier before FSK signal demodulation, two cascaded sixth-order low-pass filters employing four 'Gm-C' elements, and a digital combinational logic for decoding the FSK signals coming out of the limiters in both I-Q arms.
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Chou, Hung-Ta, and 周鴻達. "A Frequency-Shift-Keying Transceiver for Bio-Medical Signals." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/38572889023491397918.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
94
Wireless technique has greatly improved in recent years. Applications in many different field arise quickly. Biomedical-signal wireless sensor system is one of the hottest research targets. The objective of this thesis is to design a wireless interface suitable for biomedical signals. The requirements of such a interface are low power consumption、medium transmission speed and high precision. Frequency-shift-keying fits in with these requirements and is adopted. A fractional-N type phase-locked loop is used as the modulator. It has the advantages of convenience to change the frequency and high precision. Fractional-N architecture allows the lock speed、loop bandwidth and frequency resolution to be optimized at the same time. A delta-sigma modulator is also used to reduce noise. The receiver adopts direct conversion topology. Low noise amplifier enhances the weak received signal and a Gilbert mixer down-converts it to baseband by mixing it with the local oscillator signal. A limiting amplifier limits the down-converted signal to rail-to-rail level assembling the waveform of a square wave witch can be view as digital pulses. A counter-based digital demodulator extracts the data.
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Ojha, Anuj Raj. "Trellis coding on multi-amplitude continuous phase frequency shift keying /." 2007. http://proquest.umi.com/pqdweb?did=1453189151&sid=12&Fmt=2&clientId=10361&RQT=309&VName=PQD.
Full text
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Luo, Zi-Huan, and 羅子喚. "Differential Detection of Multi-h Continuous Phase Frequency Shift Keying." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/86953824273520343307.
Full textAbstract:
碩士大葉大學
電機工程研究所
87
A special class of continuous phase modulation (CPM) offers power and bandwidth efficiency , called multi-h phase-coded modulation (MHPM) where time-varying modulation indices are used. In previous researches, an optimum detector, Maximum Likelihood Sequence Detector under AWGN background, has been considered to demodulate the multi-h CPFSK and it is actually a form of VA (Viterbi algorithm) decoder. However, based on the complexity of receiver in the actual environment of mobile radio, we adopt a non-coherent differential detection to demodulate the multi-h CPFSK system. In our study, we derived the theoretical value of BER(Bit-Error-Rate) by analytical investigation and verified the accuracy by simulations. We show that the proposed architecture can indeed progress demodulation through one-bit differential detection and with wonderful BER performance. It is also interested to note the set of modulation indices with larger minimum squared Euclidean distance do not always outperform the set with smaller one.
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"Applications of optical frequency shift keying modulation format in optical networks." 2004. http://library.cuhk.edu.hk/record=b5891924.
Full textAbstract:
Deng Ning.Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.
Includes bibliographical references (leaves 62-65).
Abstracts in English and Chinese.
ABSTRACT --- p.iii
摘要 --- p.v
Chapter 1 --- BACKGROUND AND INTRODUCTION --- p.1
Chapter 1.1 --- Optical Frequency-Shift Keying (FSK) --- p.1
Chapter 1.1.1 --- Basic concepts and research hotspots of optical FSK --- p.1
Chapter 1.1.2 --- Optical FSK Transmitter and Receiver --- p.3
Chapter 1.2 --- Wavelength Division Multiplexing Optical Passive Networks --- p.8
Chapter 1.3 --- Optical Label Switching (OLS) Networks --- p.10
Chapter 1.4 --- Thesis Contribution and Organization --- p.11
Chapter 2 --- DATA RE-MODULATION ON DOWNSTREAM OPTICAL FSK SIGNALS IN WDM-PONS --- p.12
Chapter 2.1 --- overview of related works --- p.12
Chapter 2.2 --- PON ARCHITIiCTURE USING DOWNSTREAM OPTICAL FSK SIGNALS --- p.13
Chapter 2.3 --- CLS PON DEMONSTRATION USING THREE DIFFERENT OPTICAL FSK TRANSMITTERS --- p.14
Chapter 2.3.1 --- With an optical FSK transmitter based on direct modulation in a DFB laser --- p.14
Chapter 2.3.2 --- With an optical FSK transmitter based on complementary intensity modulation --- p.17
Chapter 2.3.3 --- With our proposed optical FSK transmitter based on phase modulation --- p.21
Chapter 2.4 --- System Performance by Using Phase Modulation Based FSK Transmitter…… --- p.26
Chapter 2.4.1 --- Wavelength detune of light sources --- p.27
Chapter 2.4.2 --- Detune of the DI frequency response --- p.29
Chapter 2.4.3 --- Dispersion tolerance --- p.30
Chapter 2.5 --- Summary --- p.32
Chapter 3 --- INTENSITY-MODULATED LABELLING ON OPTICAL FSK OR DPSK PAYLOADS IN OLS NETWORKS --- p.34
Chapter 3.1 --- Existing Labelling Schemes and Their Features --- p.34
Chapter 3.1.1 --- Bit serial labelling --- p.35
Chapter 3.1.2 --- Subcarrier multiplexed (SCM) labelling --- p.36
Chapter 3.1.3 --- Orthogonally modulated labelling --- p.37
Chapter 3.2 --- The Proposed 00K Labelling Scheme and OLS System Architecture --- p.38
Chapter 3.3 --- All-Optical Label Swapping and Other Critical Issues --- p.39
Chapter 3.4 --- System demonstration --- p.40
Chapter 3.5 --- Summary --- p.45
Chapter 4 --- PERFORMANCE CHARACTERIZATION OF THE ASK/FSK AND ASK/DPSK ORTHOGONAL SIGNALS --- p.46
Chapter 4.1 --- Introduction and Formulation --- p.46
Chapter 4.2 --- Theoretical Analysis --- p.48
Chapter 4.2.1 --- Optical ASK performance in orthogonal signals --- p.48
Chapter 4.2.2 --- Optical FSK performance in ASK/FSK signals --- p.49
Chapter 4.2.3 --- Optical DPSK performance in ASK/DPSK signals --- p.51
Chapter 4.3 --- Analytical and Experimental Results --- p.55
Chapter 4.4 --- Conclusion --- p.57
Chapter 5 --- SUMMARY --- p.58
Chapter 5.1 --- Thesis Summary --- p.58
Chapter 5.2 --- Future Work --- p.59
LIST OF PUBLICATIONS --- p.61
REFERENCES --- p.62
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Weng, Chun, and 翁均. "A 4-level RF Frequency-Shift Keying Demodulator for Biomedical Implants." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/44949429562052331916.
Full textAbstract:
碩士輔仁大學
電機工程學系碩士班
103
In this thesis, we propose a high spectrum-efficient frequency-shift keying (FSK) demodulator circuits. The primary application of this novel modulation technique is to send data to wireless biomedical implants at a high spectrum-efficient modulation scheme of 4-level FSK. The construction of the 4-level radio frequency FSK demodulator can be divided into three parts: Mixer, Operational Transconductance Amplifier and Digital Demodulator. For the first step, we let the received 4-level radio FSK signal and Local Oscillator signal go through the down-converted mixer, which mixes frequency to intermediate frequency and then amplify the intermediate frequency signal to full swing by sending it into the Operational Transconductance Amplifier. In the last step, we transmit the full swing intermediate frequency signal into the digital demodulator to demodulate transmitted data. The frequency of the 4-level radio FSK signal and Local Oscillator signal are operating at about 909MHz, and the frequency of down-converted intermediate frequency signal is about 50 KHz. This thesis used TSMC 1P6M 0.18um CMOS technology for simulation at the 1.8V power supply.
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Wei-yu, Li, and 李威諭. "Driving Output Circuit Design for Power Line Communication System with Frequency Shift Keying Modulation." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/70798414800458493151.
Full textAbstract:
碩士國立暨南國際大學
電機工程學系
95
Power-Line network is the most common & deepest network system in our life. Its trace can be seen as long as there are people. Since there is the complete structure network beside us, we should use it, the huge resource, well, apply all kinds of communication mode structures to Power-Line network and develop the maximum benefit by the minimum cost. At present, the development of Power-Line digital signal process chip has already quite matured. To counter with the limits of laws & the demands of market orientation of different nations, the current mainstream is LM1893 (National Semiconductor), ST7536 (SGS Thomson Co.), and SSC-P300 (Intellon Co.), each R&D team develops separately digital signal process with the complete structure & individual features. Therefore, Power-Line digital signal process chip will not be talked in this article. This study focuses on the ‘Analogy Electric Circuit Block’ of Driving Output Circuit Power-Line Communication System. Its design & analysis are to use electric circuit design skill & auxiliary analysis of packaged software to reach low loss & low delay time in signal process and raise the reliability & transmission efficiency of data transmission. After executing the designed electric circuit of this study, the real measured loss value of driving output circuit is 24dB, and the real measured signal delay time is 1.25us, all conform to our designed specification. Finally, hope this study can make some contribution to Power Line Communication System.
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Chang, Chih-Chien, and 張智謙. "Study of Multi-Ring Differential Phase Shift Keying in Orthogonal Frequency Division Multiplexing System." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/14234239603480543034.
Full textAbstract:
碩士國立臺灣海洋大學
電機工程學系
92
Abstract Wireless communication makes the interaction between the people who is far away to the others. With the digital multimedia development including image, audio and video, wireless communication goes to a new era. The technology of wireless communication is digital signal process that can promote the rate of data transmission, the quality of signals, the data confidentiality of user, and the efficiency of bandwidth. OFDM uses several subchannels to transmit data. Compared with single carrier system, the bandwidth of multicarrier communication system is much narrow. The main technologies of OFDM are Quadrature Amplitude Modulation (QAM) and Phase Shift keying (PSK). With the high speed data transmission and the system that is easy to realize, QAM is used widely. The strength of PSK is the lower transmission power, but it is difficult to realize for the two reasons. First, the data transmission rate is lower. Second, when PSK is used in M-ary, the system complication will increase. In the paper, the modulation used in system is DAPSK (Differential Amplitude and Phase Shift Keying). With means of Gray Code, it can not only avoid the problem of high prime cost in coherent demodulation but also reduce the complexity of system. Finally, we proposed a formula to improve the ring ratio of amplitude. In order to reduce PAPR in DAPSK, we used the power difference to calculate new ring ratio. It will not waste power when the amplitude is increased in Multi-Ring. Keywords : OFDM、DAPSK、Gray Code、PAPR