Dissertations / Theses on the topic 'Transmitter systems'
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1
Malkin, Moshe H. "Optimized transmitter-based signal processing for multicarrier systems /." May be available electronically:, 2009. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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Di, Rosa Gabriele. "Impact of Transmitter Distortion on Coherent Optical Systems." Thesis, KTH, Tillämpad fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-240386.
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Chu, Min. "Phase-shifting techniques for wireless multiple-antenna transmitter applications /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/6002.
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Huang, Jinliang. "Adaptive MIMO Systems with Channel State Information at Transmitter." Doctoral thesis, KTH, Kommunikationssystem, CoS, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9777.
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This dissertation presents adaptation techniques that can achieve high spectral efficiency for single user multiple-input multiple-output (MIMO) systems. Two types of adaptation techniques, adaptive modulation and adaptive powe allocation, are employed to adapt the rate and the transmit power to fading channels. We start by investigating the adaptive modulation subject to a certain bit-error-ratio (BER) constraint, either instantaneous BER constraint or average BER constraint. The resulting average spectral efficiencies are obtained in closed-form expressions. It turns out that, by employing the average BER constraint, we can achieve the optimal average spectra efficiency at the cost of prohibitive computational complexity. On the other hand, instantaneous BER constraint leads to inferior performance with little computational complexity. In order to achieve comparable performance to the average BER constraint with limited complexity, a non-linear optimization method is proposed. To further enhance the average spectra efficiency, adaptive power allocation schemes are considered to adjust the transmit power across the temporal domain or the spatial domain, depending on the specific situation. Provided the closed-form expressions of the average spectral efficiency, the optimal MIMO coding scheme that offers the highest average spectral efficiency under the same circumstances can be identified. As we take into account the effect of imperfect channel estimation, the adaptation techniques are revised to tolerate interference introduced by the channel estimation errors. As a result, the degradation with respect to the average spectral efficiency is in proportion to signal-to-noise ratio (SNR). In order to facilitate fast development and verification of the adaptation schemes proposed for various MIMO systems, a reconfigurable Link Layer Simulator (LiLaS) which accommodates a variety of wireless/wireline applications is designed in the environment of MATLAB/OCTAVE. The idea of the simulator is originated from Software Defined Radio (SDR) and evolved to suit Cognitive Radio (CR) applications. For the convenience of modification and reconfiguration, LiLaS is functionally divided into generic blocks and all blocks are parameterized.QC 20100812
5
Mella, Evans Epafras. "Transmitter precoding and receiver processing for broadband wireless systems." Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611880.
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Huang, Jin Liang. "Adaptive MIMO systems with channel state information at transmitter /." Stockholm : KTH Information and Communication Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9777.
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Eckler, Kyle. "Prototype MIMO Transmitter for Spin Stabilized Vehicles." International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595804.
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ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, NevadaThis paper describes the design of an inexpensive and scalable transmitter for a Multiple-Input Multiple-Output (MIMO) communication system. The transmitter is intended to be used in aerospace applications, especially in spin stabilized vehicles. A field programmable gate array (FPGA) in the modulator will implement a modified Alamouti space time block code which will take advantage of the cyclostationary nature of the channel to increase the system data rate.
8
Daempfling, Hauke C. "Design and implementation of the precision personnel locator digital transmitter system." Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-122006-161049/.
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Thesis (M.S.)--Worcester Polytechnic Institute.Keywords: precision personnel locator; digital systems; embedded systems; waveform generation; data communication. Includes bibliographical references (leaves 108-110).
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Lee, See Taur. "Quad-band global system for mobile communications complementary metal-oxide-semiconductor transmitter /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/6122.
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He, Jian. "Global Optimization of Transmitter Placement for Indoor Wireless Communication Systems." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/34817.
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The DIRECT (DIviding RECTangles) algorithm JONESJOTi, a variant of
Lipschitzian methods for bound constrained global optimization, has
been applied to the optimal transmitter placement for indoor wireless
systems. Power coverage and BER (bit error rate) are considered as
two criteria for optimizing locations of a specified number of
transmitters across the feasible region of the design space. The
performance of a DIRECT implementation in such applications depends
on the characteristics of the objective function, the problem
dimension, and the desired solution accuracy. Implementations with
static data structures often fail in practice because of unpredictable
memory requirements. This is especially critical in $S^4W$
(Site-Specific System Simulator for Wireless communication systems),
where the DIRECT optimization is just one small component connected
to a parallel 3D propagation ray tracing modeler running on a 200-node
Beowulf cluster of Linux workstations, and surrogate functions for a
WCDMA (wideband code division multiple access) simulator are also
used to estimate the channel performance. Any component failure of this
large computation would abort the entire design process. To make the
DIRECT global optimization algorithm efficient and robust, a set of
dynamic data structures is proposed here to balance the memory
requirements with execution time, while simultaneously adapting to
arbitrary problem size. The focus is on design issues of the dynamic data
structures, related memory management strategies, and application issues
of the DIRECT algorithm to the transmitter placement optimization for
wireless communication systems. Results for two indoor systems
are presented to demonstrate the effectiveness of the present work.Master of Science
11
Banks, Robert Edward. "The use of transmitter power control in land mobile radio systems." Thesis, University of Bath, 1987. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760571.
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Sung, Joon Hyun. "Transmitter Strategies for Closed-Loop MIMO-OFDM." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5029.
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This thesis concerns communication across channels with multiple inputs and multiple outputs. Specifically, we consider the closed-loop scenario in which knowledge of the state of the multiple-input multiple-output (MIMO) channel is available at the transmitter. We show how this knowledge can be exploited to optimize performance, as measured by the zero-outage capacity, which is the capacity corresponding to zero outage probability. On at-fading channels, a closed-loop transmitter allocates different powers and rates to the multiple channel inputs so as to maximize zero-outage capacity. Frequency-selective fading channels call for a combination of orthogonal-frequency-division multiplexing (OFDM) and MIMO known as MIMO-OFDM. This exacerbates the allocation problem because it multiplies the number of allocation dimensions by the number of OFDM tones. Fortunately, this thesis demonstrates that simple allocations are sufficient to approach the zero-outage capacity. These simple strategies exploit the tendency for random MIMO channels to behave deterministically as the number of inputs becomes large.
13
Lee, King F. "Space-time and space-frequency coded orthogonal frequency division multiplexing transmitter diversity techniques." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/14981.
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Sankaran, Mahadevan. "Transparent Asynchronous Transmitter Receiver Interface (TAXI) communications for fiber optic data links." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-01102009-063748/.
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Pascual, Iserte Antonio. "Channel state Information and joint transmitter-receiver design in multi-antenna systems." Doctoral thesis, Universitat Politècnica de Catalunya, 2005. http://hdl.handle.net/10803/6890.
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Esta tesis aborda el problema del diseño de sistemas multiantena, donde el caso más general corresponde a un canal multi-input-multi-output (MIMO) con un transmisor y un receptor con más de una antena. La ventaja de estos sistemas es que ofrecen un rendimiento mucho mejor que los de una única antena, tanto en términos de calidad en la transmisión como en capacidad entendida como número de usuarios a los que se les puede prestar servicio simultáneamente.El objetivo es diseñar conjuntamente el transmisor y el receptor, lo que depende directamente de la calidad y la cantidad de información del canal de la que se dispone. En esta tesis se analiza el impacto de dicha información en el diseño.
Primero se ha estudiado un sistema MIMO de un único usuario usando la modulación orthogonal frequency division multiplexing (OFDM) y asumiendo un conocimiento perfecto del canal en ambos extremos. La arquitectura propuesta se basa en conformación conjunta por portadora, calculándose los conformadores óptimos y proponiéndose diversas estrategias de distribución de potencia entre las portadoras con una baja complejidad. Se han analizado también las relaciones asintóticas de estas distribuciones de potencia con otras soluciones clásicas con mayor coste.
El diseño anterior se ha extendido a sistemas MIMO multiusuario, donde todos los terminales en el escenario tienen más de una antena y la información del canal es perfecta. El objetivo es la minimización de la potencia total transmitida sujeto a restricciones de tasa de error máxima para cada enlace. El problema matemático obtenido es no convexo, por lo que estrategias clásicas basadas en algoritmos de gradiente o de optimización sucesiva pueden llevar a soluciones subóptimas. Como posible alternativa se ha propuesto la aplicación de simulated annealing, una potente herramienta heurística y estocástica que permite hallar el diseño global óptimo incluso cuando el problema es no convexo.
Los errores en la información de canal disponible pueden empeorar el rendimiento del sistema si éstos no se tienen en cuenta explícitamente durante el diseño. La degradación del sistema MIMO-OFDM de un único usuario se ha estudiado en esta situación, obteniendo una expresión analítica de una cota superior de la máxima degradación relativa de la relación señal a ruido más interferencia.
El rendimiento se puede mejorar usando técnicas robustas que tengan en cuenta la presencia de dichos errores. Existen dos aproximaciones clásicas: las Bayesianas y las maximin. En las soluciones Bayesianas el problema se formula estadísticamente, donde el objetivo es optimizar el valor medio de una función de rendimiento promediada sobre la estadística del canal real condicionado a su estimación. Por otro lado, los diseños maximin se caracterizan por optimizar el peor rendimiento para cualquier posible error en la información del canal dentro de una cierta región de incertidumbre que modela el conocimiento imperfecto del mismo.
Se han mostrado dos ejemplos de diseños Bayesianos. Primero, una distribución de potencia en un sistema OFDM de una única antena que minimiza el valor medio de una cota superior de la tasa de error, y después un diseño de un transmisor multiantena con un banco de filtros que maximiza la relación señal a ruido media (SNR) o minimiza el error cuadrático medio.
Finalmente, se ha obtenido el diseño robusto maximin de un sistema MIMO de un único usuario donde en el transmisor se combinan un código bloque ortogonal espacio-tiempo, una distribución de potencia y un banco de conformadores correspondientes a los modos espaciales del canal estimado. La distribución de potencia se ha diseñado acorde a una región de incertidumbre para el error en la estimación de canal de manera que se maximiza la peor SNR en dicha región. Posteriormente, este diseño se ha extendido al caso de modulaciones adaptativas y multiportadora, mostrando que el rendimiento es mejor que para los códigos bloque otrogonales y la conformación no robusta.
This Ph.D. dissertation addresses the design of multi-antenna systems, where the most general case corresponds to a transmitter and a receiver with more than one antenna, i.e., a multiple-input-multiple-output (MIMO) channel. The main advantage is that they can provide a much better performance than single-antenna systems, both in terms of transmission quality and system capacity, i.e., number of users that can be served simultaneously.
The objective is to carry out a joint transmitter-receiver design, which depends directly on the quantity and the quality of the available channel state information (CSI). In this dissertation, the impact of the CSI on the design has been analyzed.
First, a single-user MIMO communication system has been designed assuming the use of the orthogonal frequency division multiplexing (OFDM) modulation and according to a perfect CSI at both sides. The proposed architecture is based on a joint beamforming approach per carrier. The optimum beamvectors have been calculated and several power allocation strategies among the subcarriers have been derived. These power allocation solutions have been shown to be asymptotically related to other classical designs but with a much lower computational load.
The previous design has been extended to multi-user communications, where the multi-antenna terminals in the scenario have a perfect CSI. The objective is the minimization of the total transmit power subject to maximum bit error rate (BER) constraints for each link. The mathematical optimization problem is non-convex and, therefore, classical solutions based on gradient search or alternate & maximize schemes may find a local suboptimum design. As a possible solution, the application of the simulated annealing technique has been proposed, a powerful stochastic optimization tool able to find the global optimum design even when the problem is non-convex.
The errors in the available CSI may decrease importantly the system performance if they are not taken into account explicitly in the design. This degradation has been studied for the single-user MIMO-OFDM system. An analytical expression of an upper-bound on the maximum relative signal to noise plus interference ratio degradation has been found.
The system performance can be improved when exploiting an imperfect CSI by using adequate robustness strategies. Two robust approaches have been proposed: the Bayesian and the maximin solutions. The Bayesian approach is a full statistical solution that optimizes the mean value of the performance function averaged over the statistics of the actual channel and the errors in the CSI. On the other hand, the maximin approach provides a design that optimizes the worst system performance for any possible error in a predefined uncertainty region.
Two simple examples of Bayesian designs have been provided. First, a power allocation has been derived for an OFDM system with one transmit and one receive antenna minimizing the mean value of an upper-bound on the BER. Afterwards, a design of a multi-antenna transmitter with a bank of filters and a single-antenna receiver has been proposed, whose objective is either the maximization of the mean signal to noise ratio (SNR) or the minimization of the mean square error.
Finally, a robust maximin design has been proposed for a single-user MIMO system, in which the transmitter is based on the combination of an orthogonal space time block code (OSTBC), a power allocation stage, and a set of beamformers coupling the transmission through the estimated channel eigenmodes. The power allocation has been found according to a channel estimate and an uncertainty region for the error in this estimate, so that the worst SNR for any error in the uncertainty region is maximized. This design has been then extended and applied to adaptive modulation schemes and multicarrier modulations, showing that the performance is much better than that achieved by a pure OSTBC solution or a non-robust beamforming scheme.
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Peiris, Bemini Hennadige Janath. "Resource allocation in DS-CDMA systems with side information at the transmitter." Texas A&M University, 2006. http://hdl.handle.net/1969.1/5004.
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In a multiuser DS-CDMA system with frequency selectivity, each userâÂÂs spreading
sequence is transmitted through a different channel and the autocorrelation and
the cross correlation properties of the received sequences will not be the same as
that of the transmitted sequences. The best way of designing spreading sequences
for frequency selective channels is to design them at the receiver exploiting the usersâÂÂ
channel characteristics. By doing so, we can show that the designed sequences outperform
single user AWGN performance.
In existing sequence design algorithms for frequency selective channels, the design
is done in the time domain and the connection to frequency domain properties
is not established. We approach the design of spreading sequences based on their
frequency domain characteristics. Based on the frequency domain characteristics of
the spreading sequences with unconstrained amplitudes and phases, we propose a
reduced-rank sequence design algorithm that reduces the computational complexity,
feedback bandwidth and improves the performance of some existing sequence design
algorithms proposed for frequency selective channels.
We propose several different approaches to design the spreading sequences with constrained amplitudes and phases for frequency selective channels. First, we use the
frequency domain characteristics of the unconstrained spreading sequences to find a
set of constrained amplitude sequences for a given set of channels. This is done either
by carefully assigning an already existing set of sequences for a given set of users or by
mapping unconstrained sequences onto a unit circle. Secondly, we use an information
theoretic approach to design the spreading sequences by matching the spectrum of
each userâÂÂs sequence to the water-filling spectrum of the userâÂÂs channel.
Finally, the design of inner shaping codes for single-head and multi-head magnetic
recoding channels is discussed. The shaping sequences are designed considering them
as short spreading codes matched to the recoding channels. The outer channel code
is matched to the inner shaping code using the extrinsic information transfer chart
analysis.
In this dissertation we introduce a new frequency domain approach to design
spreading sequences for frequency selective channels. We also extend this proposed
technique to design inner shaping codes for partial response channels.
17
Zhou, Lin. "Energy efficient transmitter design with compact antenna for future wireless communication systems." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/33104.
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This thesis explores a novel technique for transceiver design in future wireless systems, which is cloud radio access networks (CRANs) with single radio frequency (RF) chain antennas at each remote radio head (RRH). This thesis seeks to make three contributions. Firstly, it proposes a novel algorithm to solve the oscillatory/unstable behaviour of electronically steerable parasitic array radiators (ESPAR) when it provides multi-antenna functionality with a single RF chain. This thesis formulates an optimization problem and derives closed-form expressions when calculating the configuration of an ESPAR antenna (EA) for arbitrary signals transmission. This results in simplified processing at the transmitter. The results illustrate that the EA transmitter, when utilizing novel closed-form expressions, shows significant improvement over the performance of the EA transmitter without any pre-processing. It performs at nearly the same symbol error rate (SER) as standard multiple antenna systems. Secondly, this thesis illustrates how a practical peak power constraint can be put into an EA transceiver design. In an EA, all the antenna elements are fed centrally by a single power amplifier. This makes it more probable that during use, the power amplifier reaches maximum power during transmission. Considering limited power availability, this thesis proposes a new algorithm to achieve stable signal transmission. Thirdly, this thesis shows that an energy efficiency (EE) optimization problem can be formulated and solved in CRANs that deploy single RF chain antennas at RRHs. The closed-form expressions of the precoder and power allocation schemes to transmit desired signals are obtained to maximise EE for both single-user and multi-user systems. The results show that the CRANs with single RF chain antennas provide superior EE performance compared to the standard multiple antenna based systems.
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Kim, Kwan-Woo. "A fully-integrated all-digital outphasing transmitter for wireless communications." Diss., Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/37263.
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The objective of the proposed research is to present a new all-digital outphasing transmitter IC, a comprehensive explanation of its operation, and its performance characterization. The all-digital transmitter chip leverages flexible digital phase modulators (DPMs) to adaptively compensate for amplifier mismatches. As the DPM uses a digital input to directly modulate the RF phase of each path, the phase control becomes very simple and accurate for power amplifier (PA) gain/phase mismatch compensation. Furthermore, this digital phase modulation scheme also facilitates minimizing the distortion of an RF combiner. It is newly proposed that two distinct digital predistortion algorithms are required for perfect compensation for both PAs and a combiner. All phase calibration values can be adaptively calculated as a function of outphase angle and saved in digital look-up tables to predistort the phase inputs of two DPMs.
Various types of PAs and combiners are investigated to further enhance the performance of the outphasing transmitter. These features are implemented in a chip fabricated in a 0.18-¥ìm CMOS process and evaluated with IEEE 802.16e baseband symbols.
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Huang, Jinliang. "Adaptation in multiple input multiple output systems with channel state information at transmitter." Licentiate thesis, Stockholm : Institutionen för elektronik, dator- och programvarusystem, Kungliga tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4443.
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Kim, Hyung Joon. "Multi-standard radio transceiver architectures and radio frequency front-end design." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1110399471.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xv, 128 p.; also includes graphics (some col.). Includes bibliographical references (p. 125-128). Available online via OhioLINK's ETD Center
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Lee, Chang-Ho. "Design and development of a ku-band transmitter for satellite communication applications." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/14722.
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Imboden, Christoph Georg. "Identification of nonpersistently excited Volterra systems : applied to the linearisation of a high power transmitter /." [S.l.] : [s.n.], 1995. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=11185.
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Zakaria, Rostom. "Transmitter and receiver design for inherent interference cancellation in MIMO filter-bank based multicarrier systems." Phd thesis, Conservatoire national des arts et metiers - CNAM, 2012. http://tel.archives-ouvertes.fr/tel-00923184.
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Multicarrier (MC) Modulation attracts a lot of attention for high speed wireless transmissions because of its capability to cope with frequency selective fading channels turning the wideband transmission link into several narrowband subchannels whose equalization, in some situations, can be performed independently and in a simple manner. Nowadays, orthogonal frequency division multiplexing (OFDM) with the cyclic prefix (CP) insertion is the most widespread modulation among all MC modulations, and this thanks to its simplicity and its robustness against multipath fading using the cyclic prefix. Systems or standards such as ADSL or IEEE802.11a have already implemented the CP-OFDM modulation. Other standards like IEEE802.11n combine CP-OFDM and multiple-input multiple-output (MIMO) in order to increase the bit rate and to provide a better use of the channel spatial diversity. Nevertheless, CP-OFDM technique causes a loss of spectral efficiency due to the CP as it contains redundant information. Moreover, the rectangular prototype filter used in CP-OFDM has a poor frequency localization. This poor frequency localization makes it difficult for CP-OFDM systems to respect stringent specifications of spectrum masks.To overcome these drawbacks, filter-bank multicarrier (FBMC) was proposed as an alternative approach to CP-OFDM. Indeed, FBMC does not need any CP, and it furthermore offers the possibility to use different time-frequency well-localized prototype filters which allow much better control of the out-of-band emission. In the literature we find several FBMC systems based on different structures. In this thesis, we focus on the Saltzberg's scheme called OFDM/OQAM (or FBMC/OQAM). The orthogonality constraint for FBMC/OQAM is relaxed being limited only to the real field while for OFDM it has to be satisfied in the complex field. Consequently, one of the characteristics of FBMC/OQAM is that the demodulated transmitted symbols are accompanied by interference terms caused by the neighboring transmitted data in time-frequency domain. The presence of this interference is an issue for some MIMO schemes and until today their combination with FBMC remains an open problem.The aim of this thesis is to study the combination between FBMC and MIMO techniques, namely spatial multiplexing with ML detection. In the first part, we propose to analyze different intersymbol interference (ISI) cancellation techniques that we adapt to the FBMC/OQAM with MIMO context. We show that, in some cases, we can cope with the presence of the inherent FBMC interference and overcome the difficulties of performing ML detection in spatial multiplexing with FBMC/OQAM. After that, we propose a modification in the conventional FBMC/OQAM modulation by transmitting complex QAM symbols instead of OQAM ones. This proposal allows to reduce considerably the inherent interference but at the expense of the orthogonality condition. Indeed, in the proposed FBMC/QAM,the data symbol and the inherent interference term are both complex. Finally, we introduce a novel FBMC scheme and a transmission strategy in order to avoid the inherent interference terms. This proposed scheme (that we call FFT-FBMC) transforms the FBMC system into an equivalent system formulated as OFDM regardless of some residual interference. Thus, any OFDM transmission technique can be performed straightforwardly to the proposed FBMC scheme with a corresponding complexity growth. We develop the FFT-FBMC in the case of single-input single-output (SISO) configuration. Then, we extend its application to SM-MIMO configuration with ML detection and Alamouti coding scheme.
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Hur, Joonhoi. "A highly linear and efficient out-phasing transmitter for multi-band, multi-mode applications." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/42823.
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There have been many efforts to improve efficiency of transmitter while meeting stringent linearity requirement of modern communication system. Among the technology to enhance efficiency of linear transmitter, the out-phasing technologies, also called the linear amplification with nonlinear components (LINC), is considered as a promising technology. LINC has been studied long times, since it provides excellent linearity with high efficiency by allowing adopt high efficient switch-mode power amplifiers. However, The LINC transmitter has some technical challenges: linearity degradation due to amplitude and phase mismatches, efficiency degradation due to poor combining efficiency, and narrow frequency bandwidth due to output matching network of switching power amplifier.
In this thesis, some state-of-the-art techniques for solving the problems of LINC transmitters are presented. An unbalanced phase calibration technique compensates amplitude/phase mismatches between two parallel paths in the LINC system, and multi-level LINC (MLINC) and an uneven multi-level LINC (UMLINC) structure improve the overall power efficiency. And the reconfigurable Class-D switching PA enables multi-band operation with high efficiency and good linearity. With these techniques, the new multi-band out-phasing transmitter improves the efficiency without sacrificing the linearity performance.
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Leung, Matthew Chung-Hin. "CMOS RF SOC Transmitter Front-End, Power Management and Digital Analog Interface." Thesis, Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24664.
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With the growing trend of wireless electronics, frequency spectrum is crowded with different applications. High data transfer rate solutions that operate in license-exempt frequency spectrum range are sought. The most promising candidate is the 60 GHz multi-giga bit transfer rate millimeter wave circuit. In order to provide a cost-effective solution, circuits designed in CMOS are implemented in a single SOC.
In this work, a modeling technique created in Cadence shows an error of less than 3dB in magnitude and 5 degree in phase for a single transistor. Additionally, less than 3dB error of power performance for the PA is also verified. At the same time, layout strategies required for millimeter wave front-end circuits are investigated. All of these combined techniques help the design converge to one simulation platform for system level simulation.
Another aspect enabling the design as a single SOC lies in integration. In order to integrate digital and analog circuits together, necessary peripheral circuits must be designed. An on-chip voltage regulator, which steps down the analog power supply voltage and is compatible with digital circuits, has been designed and has demonstrated an efficiency of 65 percent with the specific area constraint. The overall output voltage ripple generated is about 2 percent.
With the necessary power supply voltage, gate voltage bias circuit designs have been illustrated. They provide feasible solutions in terms of area and power consumption. Temperature and power supply sensitivities are minimized in first two designs. Process variation is further compensated in the third design. The third design demonstrates a powerful solution that each aspect of variations is well within 10%.
As the DC conditions are achieved on-chip for both the digital and analog circuits, digital and analog circuits must be connected together with a DAC. A high speed DAC is designed with special layout techniques. It is verified that the DAC can operate at a speed higher than 3 Gbps from the pulse-shaping FIR filter measurement result.
With all of these integrated elements and modeling techniques, a high data transfer rate CMOS RF SOC operating at 60 GHz is possible.
26
Smith, Stephen E. "An investigation of the effects of electroconvulsive shock on mesolimbic dopamine and amino acid transmitter systems." Thesis, University of Oxford, 1995. http://ora.ox.ac.uk/objects/uuid:6dc583e0-cb02-4550-87cb-195ac4264f3e.
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Holguín-Sánchez, Fausto Daniel. "Spectral Shape Division Multiplexing (SSDM): Apparatus, Transmitter, Receiver and Detection." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/800.
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Wireless communication companies require to use the frequency spectrum to operate. Both frequency licenses and infrastructure to reuse frequencies are costly resources subject to increasing demand. This work introduces a novel multiplexing method that saves spectrum called Spectral Shape Division Multiplexing (SSDM). Under certain configurations, SSDM displays higher flexibility and throughput than other spectrally efficient methods.
SSDM defines the structure of a wireless multi-carrier by software. It is similar to Orthogonal Frequency Division Multiplexing (OFDM) in that both use overlapped sub-carriers to make efficient use of allocated spectrum. However, SSDM has several advantages. Where OFDM organizes sub-carriers orthogonally, SSDM allows arbitrary frequency steps enabling higher spectral efficiency. Similarly, while OFDM and other spectrally efficient methods use sinusoidal pulse forms, SSDM can use non-standard pulses providing a greater control of the carrier. In this thesis, a SSDM transceiver is implemented to reduce the spectrum utilization. SSDM presents an increase in spectral efficiency of 20% average with respect to OFDM. The cost of this gain is higher computational speed and signal to noise ratio.
The mathematical models and possible architecture for an SSDM system with sinusoidal pulses is developed. The modem is compared with other spectrally efficient methods. Similarly, the trade-offs between spectral efficiency, bit-error rates, dimension of the carrier and sub-carrier spacing are subject of analysis.
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He, Xin, and 何鑫. "Probabilistic quality-of-service constrained robust transceiver designin multiple antenna systems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48199527.
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In downlink multi-user multiple-input multiple-output (MU-MIMO)
systems, different users, even multiple data streams serving one user,
might require different quality-of-services (QoS). The transceiver should
allocate resources to different users aiming at satisfying their QoS
requirements. In order to design the optimal transceiver, channel
state information is necessary. In practice, channel state information
has to to be estimated, and estimation error is unavoidable. Therefore,
robust transceiver design, which takes the channel estimation
uncertainty into consideration, is important. For the previous robust
transceiver designs, bounded estimation errors or Gaussian estimation
errors were assumed. However, if there exists unknown distributed interference,
the distribution of the channel estimation error cannot be
modeled accurately a priori. Therefore, in this thesis, we investigate
the robust transceiver design problem in downlink MU-MIMO system
under probabilistic QoS constraints with arbitrary distributed channel
estimation error.
To tackle the probabilistic QoS constraints under arbitrary distributed
channel estimation error, the transceiver design problem is expressed
in terms of worst-case probabilistic constraints. Two methods are
then proposed to solve the worst-case problem. Firstly, the Chebyshev
inequality based method is proposed. After the worst-case probabilistic
constraint is approximated by the Chebyshev inequality, an
iteration between two convex subproblems is proposed to solve the
approximated problem. The convergence of the iterative method is
proved, the implementation issues and the computational complexity
are discussed.
Secondly, in order to solve the worst-case probabilistic constraint more
accurately, a novel duality method is proposed. After a series of reformulations
based on duality and S-Lemma, the worst-case statistically
constrained problem is transformed into a deterministic finite
constrained problem, with strong duality guaranteed. The resulting
problem is then solved by a convergence-guaranteed iteration between
two subproblems. Although one of the subproblems is still nonconvex,
it can be solved by a tight semidefinite relaxation (SDR).
Simulation results show that, compared to the non-robust method, the
QoS requirement is satisfied by both proposed algorithms. Furthermore,
among the two proposed methods, the duality method shows a
superior performance in transmit power, while the Chebyshev method
demonstrates a lower computational complexity.published_or_final_version
Electrical and Electronic Engineering
Master
Master of Philosophy
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Tirunelveli, Kanthi Saravanan. "Analysis and; design of successive approximation ADC and 3.5 GHz RF transmitter in 90nm CMOS." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33884.
Full textAbstract:
In this work, a 3.5 GHz RF Transmitter and Successive Approximation ADC design has been presented. The transmitter serves as an intermediate block which translates 350 MHz signal into 3.5 GHz signal. This signal is applied to 6-40 GHz wideband transmitter. The emphasis is on the design of Up conversion Mixer with high linearity, low noise and moderate image rejection performance. The successive approximation analog to digital converter was designed as a part of feedback loop control, which consists of a sensor circuit to detect the temperature changes in a power amplifier and the ADC to convert the sensor output to digital data. The data is used to determine the necessary control signals to restore the performance of the power amplifier. The circuits have been designed and implemented in ST Microelectronics CMOS 90nm process.
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Hanay, Oner [Verfasser], Renato [Akademischer Betreuer] Negra, and Gerd [Akademischer Betreuer] Ascheid. "Fourier-domain data-converters : new concepts for high data rate wireless transmitter systems / Oner Hanay ; Renato Negra, Gerd Ascheid." Aachen : Universitätsbibliothek der RWTH Aachen, 2020. http://d-nb.info/122799267X/34.
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Selbrede, Robert W., and Ronald Pozmantier. "INTEGRATION OF S-BAND FQPSK TELEMETRY TRANSMITTERS AND GPS-BASED TSPI SYSTEMS WITH CLOSELY SPACED ANTENNAE – A SUCCESS STORY." International Foundation for Telemetering, 2004. http://hdl.handle.net/10150/605322.
Full textAbstract:
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, CaliforniaModern spectrally efficient telemetry transmitters are beginning to find their way on a variety of airborne test platforms. Many of these platforms also include Global Positioning System (GPS)-based Time-Space-Position-Information (TSPI) instrumentation systems. Due to space and other limitations, many of these platforms have demanding antenna placement limitations requiring closely spaced antennas. This paper describes steps taken to identify and mitigate potential interference to GPS-based TSPI instrumentation systems by these new technology transmitters. Equipment characterization was accomplished to determine interference potential of the proposed new transmitters and susceptibility of several GPS TSPI receivers. Several filtering techniques were identified as possible solutions to the anticipated interference problems. Telemetry (TM)/GPS system mockups and laboratory tests of the same were accomplished. Open-air testing was then accomplished to validate laboratory results. Finally, on aircraft tests were accomplished prior to performing any aircraft system modifications. Results of these test efforts are presented for others to consider when planning similar modifications to other platforms.
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Zhao, Shaohua, and 趙少華. "The design of transmitter/receiver and high speed analog to digital converters in wireless communication systems: a convex programming approach." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41290525.
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Zhao, Shaohua. "The design of transmitter/receiver and high speed analog to digital converters in wireless communication systems : a convex programming approach /." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41290525.
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Pan, Bo. "Development of micromachined millimeter-wave modules for next-generation wireless transceiver front-ends." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24654.
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Thesis (Ph.D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.Committee Chair: John Papapolymerou; Committee Chair: Manos Tentzeris; Committee Member: Gordon Stuber; Committee Member: John Cressler; Committee Member: John Z. Zhang; Committee Member: Joy Laskar
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Lee, Kil-Hoon. "Design of signal integrity enhancement circuits." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37191.
Full textAbstract:
This dissertation is aimed at examining signal integrity degradation factors and realizing signal integrity enhancement circuits for both wired and wireless communication systems. For wired communication systems, an optical coherent system employing an electrical equalization circuit is studied as a way of extending the transmission distance limited by optical fiber dispersion mechanisms. System simulation of the optical coherent receiver combined with the feed-forward equalizers is performed to determine the design specification of the equalizer circuit. The equalization circuit is designed and implemented in a 0.18 µm complementary metal-oxide semiconductor (CMOS) process and demonstrates the capability to extend the transmission reach of long-haul optical systems over single-mode fiber to 600 km. Additionally, for wireless applications, signal integrity issues found in a full-duplex wireless communication network are examined. Full-duplex wireless systems are subject to interference from their own transmitter leakage signals; thus, a transmitter leakage cancellation circuit is designed and implemented in a 0.18 µm CMOS technology. The proposed cancellation circuit is integrated with a low-noise amplifier and demonstrates over 20 dB of transmitter leakage signal suppression.
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Chen, Ting. "Energy-Efficient Resource Allocation in OFDMA Systems." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-98683.
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In this thesis, a resource allocation problem in OFDMA is studied for the energy efficiency of wireless network. The objective is to minimize the total energy consumption which includes transmission energy consumption, and circuit energy consumption at both transmitter and receiver with required per user’s rate constraint. For problem solution, a heuristic algorithm with low computational complexity and suboptimal solution is proposed, developed in two steps with an increasing order of complexity. Besides, a bounding scheme based on model linearization of formulated nonlinear system model is also proposed to give lower and upper bounds for both small- and large-scale OFDMA network for further algorithm performance evaluation, while the implemented exhaustive search is only capable to provide the optimal solution for small-scale instance for algorithm performance evaluation. Numerical results show that the proposal heuristic algorithm can achieve near-optimal performance with applicable computational complexity even for large-scale networks, and that the bounds from the bounding scheme are very tight for both small- and large-scale OFDMA networks.
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Horta, Ricardo de Lins e. "Consequences of adversity on the development of attachment-related neuro transmitter systems: integrative review and analysis of Brazilian federal policies for early childhood." Universidade Federal de Minas Gerais, 2012. http://hdl.handle.net/1843/BUOS-94MJMM.
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Decades of research have shown that abuse and neglect in early childhood increase the probability of unhealthy and psychopathological outcomes in adulthood. However, mechanisms concerning mediator and moderator variables are not completely clear. Drawing from Bow|bys Attachment Theory and evolutionary-developmental models, this work aims to uncover the effects of gene-environment interactions in neurotransmitter systems related to attachment styles. It is hypothesized that early adversity affects the development of decision making, emotion regulation and social bonding behaviors in a lifelong perspective, due to phylogenetically and evolutionary causes. Using the integrative review method, literature on gene-environment interplay and attachment behavior is analysed, particularly experiments on genetic polymorphisms linked to dopamine, serotonin, oxytocin/vasopressin and opioid neurotransmitter systems. Results of experiments so far conducted are not straightforward, due mainly to design limitations and to the multilevel complexity between genetic polymorphisms and social behavior. However, research does provide good evidence on the importance and efficacy of early intervention. In an evidence- based policy perspective, it is claimed that Brazilian federal policies toward children have significantly advanced since 1988, but there is still much to be done. Neuroscientific, genetic and epigenetic studies may help to explain why changing early
environments is so important and what are the most effective ways to do it, considering the existing political and institutional constraints and the dynamic reality of policy networks.
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Xing, Chengwen, and 邢成文. "Linear minimum mean-square-error transceiver design for amplify-and-forward multiple antenna relaying systems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44769738.
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Sekkiou, Imene. "Design of communication systems based on broadband sources for fiber and free space optical links." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/172542.
Full textAbstract:
[ES] Las comunicaciones ópticas inalámbricas (OWC) constituyen una tecnología muy prometedora para el desarrollo de futuras comunicaciones inalámbricas. De hecho, ha despertado un interés creciente entre los investigadores y varias empresas de todo el mundo trabajan actualmente en el desarrollo de redes inalámbricas de muy alta velocidad. Las comunidades científica e industrial consideran la OWC como una tecnología complementaria en sus diversas formas: comunicaciones ópticas en el espacio libre (FSO), comunicaciones de luz visible (VLC) o fidelidad de la luz (Li-Fi). El espectro óptico ha sido considerado durante muchos años como una gran oportunidad para las comunicaciones inalámbricas, especialmente debido a la saturación del espectro de radiofrecuencia (RF).
Esta disertación trata del uso de fuentes de banda ancha en sistemas de transmisión de luz visible (VLC), así como en sistemas de transmisión en el espectro infrarrojo por fibra óptica. En el trabajo de investigación realizado se pueden distinguir tres partes:
En la primera parte, se considera el estudio y la simulación de componentes de Diodos Emisores de Luz (LED) con el software WIEN2k centrándose en las propiedades ópticas y eléctricas de los elementos II-VI.
La segunda parte trata del diseño, la implementación y las pruebas de diferentes prototipos de comunicación VLC para la transmisión analógica y digital en modo simplex y semidúplex. Hemos demostrado un sistema OWC empleando una fuente de banda ancha (LED) para la transmisión no sólo de datos, sino también para la transmisión inalámbrica de energía. Además, se aborda el problema de la sincronización y la detección del nivel "1" o "0" de un bit en los sistemas de comunicación inalámbrica óptica implementados que surge como consecuencia de la atenuación de la luz a lo largo de la distancia y al problema de la pérdida de línea de visión (NLOS) entre el emisor y el receptor. Para hacer frente a este problema, se ha proporcionado un protocolo de comunicación que garantiza la transmisión fiable de datos digitales con un algoritmo de detección de nivel de bits adaptativo y se ha demostrado su eficacia mediante la transmisión de textos e imágenes.
Además, esta tesis aporta una solución para la implementación de transmisores multiplexados en redes con división de longitud de onda (WDM) para formatos de modulación con multiplexación por división de frecuencia ortogonal (OFDM) basados en el uso de fuentes de banda ancha en el espectro infrarrojo para redes de fibra bidireccionales centralizadas. A pesar de las limitaciones impuestas por la dispersión cromática en el uso de este tipo de fuentes ópticas, la inclusión de ciertas estructuras antes de la detección permite la transmisión de señales OFDM en enlaces ópticos. En este trabajo se ha demostrado experimentalmente la reutilización de portadoras, la asignación dinámica de ancho de banda y la transmisión de señales OFDM multibanda mediante el uso de fuentes ópticas de banda ancha en redes WDM.
Los principales resultados obtenidos en cada parte de esta tesis doctoral muestran los procedimientos de estudio, la eficacia de las soluciones propuestas y las limitaciones encontradas.[CA] Les comunicacions òptiques sense fils (OWC) constitueixen una tecnologia molt prometedora per al desenvolupament de futures comunicacions sense fils. De fet, ha despertat un interés creixent entre els investigadors i diverses empreses de tot el món treballen actualment en el desenvolupament de xarxes sense fils de molt alta velocitat. Les comunitats científica i industrial consideren la OWC com una tecnologia complementària en les seues diverses formes: comunicacions òptiques en l'espai lliure (FSO), comunicacions de llum visible (VLC) o fidelitat de la llum (Li-Fi). L'espectre òptic ha sigut considerat durant molts anys com una gran oportunitat per a les comunicacions sense fils, especialment a causa de la saturació de l'espectre de radiofreqüència (RF). Aquesta dissertació tracta de l'ús de fonts de banda ampla en sistemes de transmissió de llum visible (VLC), així com en sistemes de transmissió en l'espectre infraroig per fibra òptica. En el treball de recerca realitzat es poden distingir tres parts: ¿ En la primera part, es considera l'estudi i la simulació de components de Díodes Emissors de Llum (LED) amb el software WIEN2k centrant-se en les propietats òptiques i elèctriques dels elements II-VI. ¿ La segona part tracta del disseny, la implementació i les proves de diferents prototips de comunicació VLC per a la transmissió analògica i digital de manera simplex i semidúplex. Hem demostrat un sistema OWC emprant una font de banda ampla (LED) per a la transmissió no sols de dades, sinó també per a la transmissió sense fil d'energia. A més, s'aborda el problema de la sincronització i la detecció del nivell "1" o "0" d'un bit en els sistemes de comunicació sense fil òptica implementats, que sorgeix a conseqüència de l'atenuació de la llum al llarg de la distància i al problema de la pèrdua de línia de visió (NLOS) entre l'emissor i el receptor. Per a fer front a aquest problema, s'ha proporcionat un protocol de comunicació que garanteix la transmissió fiable de dades digitals amb un algorisme de detecció de nivell de bits adaptatiu i s'ha demostrat la seua eficàcia mitjançant la transmissió de textos i imatges. ¿ A més, aquesta tesi aporta una solució per a la implementació de transmissors multiplexats en xarxes amb divisió de longitud d'ona (WDM) per a formats de modulació amb multiplexació per divisió de freqüència ortogonal (OFDM) basats en l'ús de fonts de banda ampla en l'espectre infraroig per a xarxes de fibra bidireccionals centralitzades. Malgrat les limitacions imposades per la dispersió cromàtica en l'ús d'aquest tipus de fonts òptiques, la inclusió d'unes certes estructures abans de la detecció permet la transmissió de senyals OFDM en enllaços òptics. En aquest treball s'ha demostrat experimentalment la reutilització de portadores, l'assignació dinàmica d'amplada de banda i la transmissió de senyals OFDM multibanda mitjançant l'ús de fonts òptiques de banda ampla en xarxes WDM. Els principals resultats obtinguts en cada part d'aquesta tesi doctoral mostren els procediments d'estudi, l'eficàcia de les solucions proposades i les limitacions trobades.
[EN] Optical wireless communication (OWC) is a very promising technology for future wireless communications developments. It has attracted increasing interest from researchers and several companies around the world are currently working on the development of very high-speed wireless networks. The scientific and industrial communities believe that OWC will be a complementary technology in its various forms: Free Space Optical communications (FSO), Visible Light Communications (VLC), Light Fidelity (Li-Fi). In fact, the optical spectrum has been considered for many years as a great opportunity for wireless communications especially due to the saturation of the radio frequency (RF) spectrum. This dissertation deals with the use of broadband sources in visible light transmission systems (VLC) as well as fiber optic systems. To carry out the research, three parts can be distinguished: In the first part, we consider the study and simulation of Light Emitting Diode (LED) components with the WIEN2k software by focusing on the optical and electrical properties of elements II-VI. The second part deals with the design, implementation and testing of different VLC communication prototypes for analog and digital transmission in simplex and half-duplex mode. We have demonstrated that an OWC system using a broadband source (i.e. an LED) can be used not only for data transmission, but also for wireless power transmission. Moreover, the synchronization problem and the detection of level "1" or "0" of a bit often arise in the optical wireless communication systems. This is a result of the attenuation nature of the light over the distance and the problem of Non Line-Of-Sight (NLOS) between the emitter and the receiver. To deal with this problem, a communication protocol ensuring reliable digital data transmission with an adaptive bit level detection algorithm has been provided and its effectiveness has been demonstrated by the transmission of texts and images. In addition, this thesis provides a solution for the implementation of wavelength division multiplexed - orthogonal frequency division multiplexed (WDM-OFDM) transmitters based on the use of broadband sources in the infrared spectrum for centralized bidirectional fiber networks. Despite the chromatic dispersion that avoids the use of this type of optical sources, the inclusion of certain structures before detection allows the transmission of OFDM signals in optical links. Carrier reuse, dynamic bandwidth allocation and multiband OFDM signals transmission will be experimentally demonstrated by using optical broadband sources in WDM networks. The main results obtained during this thesis work demonstrate the study procedures, for each part, the effectiveness of the proposed solutions as well as the constraints encountered.
Sekkiou, I. (2021). Design of communication systems based on broadband sources for fiber and free space optical links [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172542
TESIS
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Pendyala, Chandra Mohan. "On the optimal location of transmitters for micro-cellular radio communication system design." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-07112009-040406/.
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Khlif, Wassim. "Design of Tunable Low-Noise Amplifier in 0.13um CMOS Technology for Multistandard RF Transceivers." Digital WPI, 2007. https://digitalcommons.wpi.edu/etd-theses/714.
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The global market of mobile and wireless communications is witnessing explosive growth in size as well as radical changes. Third generation (3G) wireless systems have recently been deployed and some are still in the process. 3G wireless systems promise integration of voice and data communications with higher data rates and a superior quality of service compared to second generation systems. Unfortunately, more and more communication standards continue to be developed which ultimately requires specific RF/MW and baseband communication integrated circuits that are designed for functionality and compatibility with a specific type of network. Although communication devices such as cellular phones integrate different services such as voice, Bluetooth, GPS, and WLAN, each service requires its own dedicated radio transceiver which results in high power consumption and larger PCB area usage. With the rapid advances in silicon CMOS integrated circuit technology combined with extensive research, a global solutionswhich aims at introducing a global communication system that encompasses all communication standards appears to be emerging. State of the art CMOS technology not only has the capability of operation in the GHz range, but it also provides the advantage of low cost and high level of integration. These features propel CMOS technology as the ideal candidate for current trends, which currently aim to integrate more RF/MW circuits on the same chip. Armed with such technology ideas such as software radio look more attainable than they ever were in the past. Unfortunately, realizing true software radio for mobile applications still remains a tremendous challenge since it requires a high sampling rate and a wide-bandwidth Analog-to-Digital converter which is extremely power hungry and not suitable for battery operated mobile devices. Another approach to realize a flexible and reconfigurable RF/MW transceiver that could operate in a diverse mobile environment and provides a multiband and multistandard solution. The work presented in this thesis focuses on the design of an integrated and tunable low-noise amplifier as part of software defined radio (SDR).
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Bose, Biswojit. "Bit error rate estimation in WiMAX communications at vehicular speeds using Nakagami-m fading model." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/530.
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The wireless communication industry has experienced a rapid technological evolution from its basic first generation (1G) wireless systems to the latest fourth generation (4G) wireless broadband systems. Wireless broadband systems are becoming increasingly popular with consumers and the technological strength of 4G has played a major role behind the success of wireless broadband systems. The IEEE 802.16m standard of the Worldwide Interoperability for Microwave Access (WiMAX) has been accepted as a 4G standard by the Institute of Electrical and Electronics Engineers in 2011. The IEEE 802.16m is fully optimised for wireless communications in fixed environments and can deliver very high throughput and excellent quality of service. In mobile communication environments however, WiMAX consumers experience a graceful degradation of service as a direct function of vehicular speeds. At high vehicular speeds, the throughput drops in WiMAX systems and unless proactive measures such as forward error control and packet size optimisation are adopted and properly adjusted, many applications cannot be facilitated at high vehicular speeds in WiMAX communications. For any proactive measure, bit error rate estimation as a function of vehicular speed, serves as a useful tool. In this thesis, we present an analytical model for bit error rate estimation in WiMAX communications using the Nakagami-m fading model. We also show, through an analysis of the data collected from a practical WiMAX system, that the Nakagami-m model can be made adaptive as a function of speed, to represent fading in fixed environments as well as mobile environments.
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Nystøyl, Bjarte Løken. "HDMI Transmitter." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elektronikk og telekommunikasjon, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18483.
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HDMI is the de facto global standard for connecting HD components and bridging the gap between consumer electronics and personal computer products, making it a priority to develop efficient hand-held, battery-powered units that support the standard.This is a study into how to design a low power and high performance system that can transmit HDMI-signals to a valid HDMI-receiver. The main priority is to implement the TMDS part of a HDMI-transmitter, where parallel data is encoded and serialized at high frequencies. The theory chapters provides an orderly summary of the complex workings of the HDMI-standard, in addition to an introduction to high-performance digital circuit design. This is followed by a system specification chapter, which sets the constraints of the design and discusses the hardware requirements. The subsequent chapter first deals with the design of a straightforward, basic HDMI-transmitter, before moving on to an enhanced design process. The basic design is used as a base for discussions in regard to how effective the suggested enhancement techniques are. The improvements result in an enhanced design able to operate at 742,5 MHz and support High-Definition video at the impressive resolution of 1080p30. This is achieved by using a 180nm, low-leakage library, and the final design consists of approximately 24.000 unit-sized transistor equivalents, consuming approximately a total of 13,6 mW.
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Toonstra, Jason Paul. "A radio transmitter fingerprinting system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23529.pdf.
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Kim, Hyungwook. "CMOS radio-frequency power amplifiers for multi-standard wireless communications." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/44786.
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The development of multi-standard wireless communication systems with low cost and high integration is continuously requested and accompanied by the explosive growth of the wireless communication market. Although CMOS technology can provide most building blocks in RF transceivers, the implementation of CMOS RF power amplifiers is still a challenging task. The objective of this research is to develop design techniques to implement fully-integrated multi-mode power amplifiers using CMOS technology.
In this dissertation, a load modulation technique with tunable matching networks and a pre-distortion technique in a multi-stage PA are proposed to support multi-communication standards with a single PA. A fully-integrated dual-mode GSM/EDGE PA was designed and implemented in a 0.18 um CMOS technology to achieve high output power for the GSM application and high linearity for the EDGE application. With the suggested power amplifier design techniques, fully-integrated PAs have been successfully demonstrated in GSM and EDGE applications.
In Addition to the proposed techniques, a body-switched cascode PA core is also proposed to utilize a single PA in multi-mode applications without hurting the performance. With the proposed techniques, a fully-integrated multi-mode PA has been implemented in a 0.18 um CMOS technology, and the power amplifier has been demonstrated successfully for GSM/EDGE/WCDMA applications.
In conclusion, the research in this dissertation provides CMOS RF power amplifier solutions for multiple standards in mobile wireless communications with low cost and high integration.
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Kumar, Ajay. "A wide dynamic range high-q high-frequency bandpass." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28126.
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Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.Committee Chair: Allen Phillip; Committee Member: Hasler Paul; Committee Member: Keezer David; Committee Member: Kenny James; Committee Member: Pan Ronghua.
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Barale, Francesco. "Design of integrated frequency synthesizers and clock-data recovery for 60 GHz wireless communications." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37216.
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In this dissertation, the development of the first 60 GHz-standard compatible fully integrated 4-channel phase-locked loop (PLL) frequency synthesizer has been presented. The frequency synthesizer features third-order single loop architecture with completely integrated passive loop filter that does not require any additional external passive component. Two possible realizations of fully integrated clock and data recovery (CDR) circuits suitable for 60 GHz-standard compliant base band signal processing have been presented for the first time as well. The two CDRs have been optimized for either high data rate (3.456 Gb/s) or very low power consumption (5 mW) and they both work with a single 1 V supply.
The frequency synthesizer is intended to generate a variable LO frequency in a fixed-IF heterodyne transceiver architecture. In such configuration the channel selection is implemented by changing the LO frequency by the required frequency step. This method avoids quadrature 50 GHz up/down-conversion thereby lowering the LO mixer design complexity and simplifying the LO distribution network. The measurement results show the PLL locking correctly on each of the four channels while consuming 60 mW from a 1 V power supply. The worst case phase noise is measured to be -80.1 dBc/Hz at 1 MHz offset from the highest frequency carrier (56.16 GHz). The output spectrum shows a reference spur attenuation of -32 dBc. The high data rate CDR features a maximum operating data rate in excess of 3.456 Gb/s while consuming 30 mW of power. The low power CDR consumes only 5 mW and operates at a maximum data rate of 1.728 Gb/s. Over a 1.5 m 60 GHz wireless link, both CDRs allow 95% reduction of the pulse shaping generated input peak-to-peak jitter from 450 ps down to 50 ps.
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Sun, Luotao. "A fast radio transmitter identification system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0003/MQ41785.pdf.
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Al, Mahmud Shamsul Arefeen. "Wireless Power Transfer : Machine Learning Assisted Characteristics Prediction for Effective Wireless Power Transfer Systems." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-286673.
Full textAbstract:
One of the main challenges in wireless power transfer (WPT) devices is performance degradation when the receiver’s position and characteristics vary. The variations in the system parameters such as load impedance and coupling strength in WPT devices affect performance characteristics such as output voltage and power. When the system parameters are different from the optimal operating conditions, the performances are degraded. Therefore, the load impedance and coupling strength must be monitored to do the necessary optimization and control. However, such control approaches require additional sensing circuits and a data communication link between transmitter- and receiver-sides. This study proposes a new machine learning (ML) assisted WPT system that predicts the power delivered to the receiver by only using measurements at the transmitter-side. In addition, a method is also proposed to estimate load impedance and coupling coefficient using machine learning approach. We study what parameters measurable at the transmitter-side can be used to predict the output power delivered to receivers at variable load impedance and coupling strengths. In the proposed method, the output power of an inductor-capacitor-capacitor (LCC)-Series tuned WPT system is successfully predicted only using the measured root-mean-square (RMS) of the input current. Random forest algorithm has shown best accuracy to estimate the output power based on transmitter-side parameters only. The proposed approach is experimentally validated using a laboratory prototype. Harmonic components of the input current are used to assess the load impedance and coupling coefficient successfully. Multi-output regression has the highest accuracy for estimating the load impedance and coupling coefficient. The proposed ML algorithm is also used to classify the turn-on and -off regimes to ensure high-efficient operation.En av de viktigaste utmaningarna med trådlösa kraftöverföring enheter är degraderingen av prestandan när mottagarens position och egenskaper varierar. Variationerna av systemets parametrar, såsom belastningsmotstånd och kopplings styrka i WPT-anordning, påverkar prestanda egenskaperna såsom spänning och effekt. När system parametrarna skiljer sig från de optimala drifts förhållandena, försämras prestandan. Därför måste luftmotståndet och kopplings styrkan övervakas, för att göra nödvändig optimering och kontroll. Sådana styrmetoder kräver emellertid ytterligare avkännings kretsar, och en data kommunikationslänk mellan sändar- och mottagarsidan. Denna studie föreslår ett nytt maskininlärning assisterat WPT-system, som förutsäger kraften som levereras till mottagaren genom att endast använda mätningar på sändarsidan. Dessutom föreslås en metod för att detektera belastningsimpedans och kopplings koefficient med användning av maskin inlärningsmetoder. Vi studerar vilka parametrar som är mätbara på sändarsidan och som kan användas för att förutsäga utgången effekten som levereras till mottagare vid varierande belastningsmotstånd och kopplings nivåer. I den föreslagna metoden förutses framgångs effekten för ett induktor-kondensator-kondensator LCCserie avstämt WPT-system endast framgångsrikt med hjälp av det uppmätta effektivvärdet för ingångs strömmen. Slumpmässig skogsalgoritm har visat exceptionell noggrannhet för att uppskatta uteffekten endast baserat på sändarsidans parametrar. Den föreslagna metoden valideras experimentellt med användning av en laboratorium prototyp. Harmoniska komponenter i ingångs strömmen används för att framgångsrikt bedöma last motståndet och kopplings koefficienten. Multi-utgångsregression har verkat vara mycket exakt för att uppskatta belastningsimpedans och kopplingskoefficient. Den föreslagna maskininlärning algoritmen används också för att klassificera start-och-off-regimer för att säkerställa hög effektiv drift.
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Korol, Victor. "The predistortion system for an ultrawideband transmitter." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p1470298.
Full textAbstract:
Thesis (M.S.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed December 2, 2009). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 29).