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Duffek, Luděk. "Modulátor QAM." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217451.
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The thesis focuses on consideration of possible ways how to realize multi-state modulators for a laboratory instrument. This instrument will illustrate signals, which partake on generation QAM modulation. The design of the laboratory instrument includes theoretic schemata and the execution of a prototype. There are theoretical facts of multi-state signals and multi-state modulations in this thesis. A simple block diagram of the laboratory instrument is made by the theory of creating quadrature amplitude modulation. For each block there are made several schemata, which are compiled to the global scheme. A printed circuit board and the structure items are made by the aid of the global scheme. The next part is devoted to a software facility for a used microprocessor, which ensures the whole function of the laboratory instrument. The final section deals with measuring, which checks the function of the modulator and the right setting coder’s constellation diagrams.
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BRAVO, MARCO CESAR DE CASTRO. "CARRIER RECOVERY IN QAM SYSTEMS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1991. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=8957@1.
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É feito um estudo sobre o problema da recuperação de
portadora em sistemas com modulação de amplitude em
quadratura (QAM) com atenção especial aos sistemas QAM-64
utilizados nos sistemas rádio digitais. Após um revisão da
literatura, focalizando a evolução recente das estruturas
de sincronização de fase em sistemas QAM, é realizada uma
dedução teórica da estrutura ótima, pelo critério MAP. Em
seguida é abordado o problema da aquisição em presença de
erros de fase e freqüência. Entre diversas alternativas
para melhoria de tempos de aquisição é examinado em
detalhe um esquema proposto por Sari e Moridi para
detenção conjunta de fase e freqüência. Finalmente, é
examinada a implementação digital dos esquemas
anteriormente considerados e sua utilização em um receptor
QAM. Através de simulação, alguns resultados sobre o
desempenho deste receptor são avaliados em presença de
desvanecimento seletivo.A study is carried out on the problem of carier recovery in digital communication systems with quadrature amplitude modulation (QAM), giving special attention to 64-QAM systems used in digital radio. After a literature survey, focusing the evolution of the recent phase synchronization structures for QAM systems, a theoretical development for the optimum structure is made based on the MAP criteria. Next, the problem of acquisition in the presence of phase and frequency errors is considered. Among many alternatives for the reduction of the acquisition period, the scheme prosoed by Sari and Moridi for joint phase and frequency acquisition is analyzed in detail. Finaly, digital implementattion of the considered schemes and their use in a QAM receiver are studied. By means of simulation, some results about the performance of the receiver are evaluated in the presence of selective fading.
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Meintrup, David. "Soft-Decodierung für QAM-modulierte Signale." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=966280776.
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Seo, Jongsoo. "Power-efficient multi-ary QAM systems." Thesis, University of Ottawa (Canada), 1988. http://hdl.handle.net/10393/5153.
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Mathiopoulos, Panayotis. "On bandwidth-efficient QAM transmission systems." Thesis, University of Ottawa (Canada), 1989. http://hdl.handle.net/10393/6040.
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Webb, William. "QAM techniques for digital mobile radio." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385448.
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Giraudo, Elvio Cesar. "Sistema de transmissao digital {QAM 2." [s.n.], 1994. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260464.
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Orientador: Rege Romeu ScarabucciTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica
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Resumo: Este trabalho tem como finalidade mostrar uma alternativa de transmissão-recepção digital visando melhorar a eficiência e o desempenho em sistemas de modulação digital. Neste sentido, propomos o sistema chamado {QAM}² que basicamente, consiste na transmissão de duas constelações QAM de forma superposta...Observação: O resumo na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: This work shows a new technique for digital transmission that enhances bit error performance and spectral efficiency. The new technique, called {QAM}², is a method of transmitting two digital QAM signals using overlapping bandwidths, namely the transmission of two QAM constellations with common spectrum
Doutorado
Doutor em Engenharia Elétrica
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Liu, Tao, Changyu Lin, and Ivan B. Djordjevic. "Advanced GF(3^2) nonbinary LDPC coded modulation with non-uniform 9-QAM outperforming star 8-QAM." OPTICAL SOC AMER, 2016. http://hdl.handle.net/10150/621525.
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In this paper, we first describe a 9-symbol non-uniform signaling scheme based on Huffman code, in which different symbols are transmitted with different probabilities. By using the Huffman procedure, prefix code is designed to approach the optimal performance. Then, we introduce an algorithm to determine the optimal signal constellation sets for our proposed non-uniform scheme with the criterion of maximizing constellation figure of merit (CFM). The proposed nonuniform polarization multiplexed signaling 9-QAM scheme has the same spectral efficiency as the conventional 8-QAM. Additionally, we propose a specially designed GF(32) nonbinary quasi-cyclic LDPC code for the coded modulation system based on the 9-QAM non-uniform scheme. Further, we study the efficiency of our proposed non-uniform 9-QAM, combined with nonbinary LDPC coding, and demonstrate by Monte Carlo simulation that the proposed GF(23) nonbinary LDPC coded 9-QAM scheme outperforms nonbinary LDPC coded uniform 8-QAM by at least 0.8dB. (C) 2016 Optical Society of America
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Lemos, Gléverson Fabner Condé. "Técnicas de detecção e implementação em FPGA de modulações QAM de ordem elevada." Universidade Federal de Juiz de Fora (UFJF), 2011. https://repositorio.ufjf.br/jspui/handle/ufjf/4724.
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A presente dissertação versa sobre técnicas de baixo custo para detecção, modulação e demodulação de constelações M-QAM (quadrature amplitude modulation) de ordem elevada, ou seja, M = 2n, n = {2,3, · · · ,16}. Al´em disso, s˜ao propostas constelações alternativas para M-QAM, M = 22n, n = {1,2, · · · ,8}, que buscam minimizar a PAPR (peak to average power ratio) quando um sistema OFDM (orthogonal frequency division multiplexing) ´e utilizado para a transmissão de dados. Uma implementação, de baixo custo e em dispositivo FPGA (field programmable gate array), de um esquema de modulação constante e adaptativa para sistemas OFDM, quando a modulação é MQAM, M = 22n, n = {1,2, · · · ,8}, é descrita e analisada. O desempenho das técnicas de detecção propostas é avaliado através de simulações computacionais quando o ruído é AWGN (additive white Gaussian noise) e AIGN (additive impulsive Gaussian noise). Os resultados em termos de BER × Eb/N0 indicam que as perdas de desempenho geradas com as técnicas propostas não são significativas e, portanto, tais técnicas são candidatas adequadas para a implementação de um sistema OFDM com elevada eficiência espectral. Os resultados computacionais revelam ainda que as propostas alternativas para constelações M-QAM reduzem a PAPR, mas, em contrapartida, degradam consideravelmente a BER. Finalmente, a análise da complexidade computacional das técnicas de detecção e demodulação, as quais foram implementadas em dispositivo FPGA, indica que há uma redução do custo computacional, ou seja, redução do uso de recursos de hardware do dispositivo FPGA quando tais técnicas são implementadas para a demodulação e detecção de símbolos M-QAM de ordem elevada.
This dissertation deals with low-cost techniques for detection, modulation and demodulation of high order M-QAM (quadrature amplitude modulation) constellations, i.e., M = 2n, n = {2,3, · · · ,16}. In addition, alternative constellations are proposed to M-QAM, M = 22n, n = {1,2, · · · ,8}, which seek to minimize the PAPR (peak to average power ratio) when an OFDM (orthogonal frequency division multiplexing) system is used for data transmission. A low-cost implementation using a FPGA (field programmable gate array) device of a modulation scheme for constant and adaptive OFDM systems when the modulation is M-QAM, M = 22n, n = {1,2, · · · ,8}, is described and analyzed. The performance of the proposed detection techniques is evaluated through computer simulations when the noise is AWGN (additive white Gaussian noise) and AIGN (additive impulsive Gaussian noise). The results in terms of BER × Eb/N0 indicate that the performance losses generated by the proposed techniques are not significant and, therefore, such techniques are appropriate candidates for the implementation of an OFDM system with high spectral efficiency. The computational results reveal that the alternative proposals for M-QAM constellations reduce the PAPR, but, considerably degrade the BER. Finally, the analysis of computational complexity of detection and demodulation techniques, which were implemented in a FPGA device, indicates that there is a computational cost reduction, i.e., a reduction of resource usage of hardware device such as FPGA when these techniques are implemented for the demodulation and detection of high-order M-QAM symbols.
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Selvakumar, Vinodhkumar, Samuel Nemalladinne, and Premkumar Arumugam. "Analysis of LTE Radio Frame by eliminating Cyclic Prefix in OFDM and comparison of QAM and Offset-QAM." Thesis, Linnéuniversitetet, Institutionen för datavetenskap, fysik och matematik, DFM, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-21602.
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Spectral efficiency is the key factor for the development of future wireless communications. Orthogonal Frequency Division Multiple Access (OFDMA) is the multiple access technology used at physical layer of latest wireless communication technologies. Anything on the improvement or overcoming the disadvantage of the present system will be considered for the future wireless systems. Long Term Evolution (LTE) is one of the 4th generation wireless communications and it is taken as the reference system in this thesis. The main concern of this thesis is to analyze the LTE radio frame. We designed and simulated the OFDM system with cyclic prefix, its Bit Error Rate (BER) is verified by changing the Signal to Noise Ratio (SNR) value and we investigated the OFDM system by eliminating the cyclic prefix. By eliminating cyclic prefix bandwidth efficiency is achieved, though using cyclic prefix in OFDM has more advantages. Filter banks are used to compensate the advantages of cyclic prefix when it is removed. Introducing Offset in QAM results in less distortion and amplitude fluctuations. We designed, simulated and compared the QAM digital modulation with Offset-QAM digital modulation its BER vs. SNR are verified using simulations on MATLAB.
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Kadhim, Abdul-Ka. "Detection of coded and distorted QAM signals." Thesis, Loughborough University, 1989. https://dspace.lboro.ac.uk/2134/31896.
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The aim of this study is to devise detection processes for digital modems operating at rates of 9600 bit/s and more over telephone lines, using coded QAM signals. The baseband representation of QAM systems and the signal distortion introduced by the telephone circuits are first investigated to derive a suitable model for the simulation of data transmission systems, using a digital computer.
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AraÃjo, Daniel Costa. "DetecÃÃo de Sinais m-QAM NÃo-Ortogonais." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8373.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorEste trabalho apresenta estudos sobre sistemas de comunicaÃÃo cujos sinais utilizados para a transmissÃo das informaÃÃes sÃo nÃo-ortogonais, superpostos em frequÃncia, e com espaÃamento entre portadoras menor do que a taxa de sÃmbolo. As pesquisas estÃo direcionadas na obtenÃÃo de estruturas de transmissor e receptor Ãtimos e sub-Ãtimos, na modelagem e anÃlise matemÃtica dos sistemas incluindo o canal, em propostas de estratÃgias para detecÃÃo de sÃmbolo, e na avaliaÃÃo de desempenho. SÃo propostas sete estratÃgias de recepÃÃo de N sinais m-QAM nÃo-ortogonais atravÃs do canal AWGN. Dentre as estratÃgias de detecÃÃo duas sÃo Ãtimas e as outras cinco sÃo subÃtimas. As duas estruturas de receptores Ãtimos apresentados neste trabalho sÃo: o receptor de mÃxima verossimilhanÃa (ML) clÃssico e o receptor de mÃxima verossimilhanÃa com base na decomposiÃÃo de Gram-Schmidt. Os receptores sub-Ãtimos desenvolvidos neste trabalho sÃo de dois tipos: receptores com equalizaÃÃo linear e receptores com equalizaÃÃo nÃo-linear. O primeiro tipo de receptor à desenvolvido com base nos critÃrios de erro quadrÃtico mÃdio mÃnimo (MMSE) e o de forÃagem a zero (ZF). à apresentado o desenvolvimento analÃtico do projeto de cada uma das arquiteturas de receptores lineares, assim como à determinado o erro dos estimadores. Os receptores com equalizaÃÃo nÃo-linear sÃo baseados no cancelamento de interferÃncia sucessiva (SIC). Neste trabalho, à proposta uma modificaÃÃo no algoritmo do SIC original, resultando em uma nova arquitetura de equalizaÃÃo. O desempenho dos receptores propostos à avaliado em diferentes condiÃÃes de nÃmero de portadoras e de grau de superposiÃÃo espectral atravÃs de simulaÃÃo computacional. Por fim, sÃo apresentados as conlusÃes e as perspectivas futuras de pesquisa.
This work presents studies on communication systems, whose signals used for transmission of information are non-orthogonal, overlapping in frequency and carrier spacing less than the rate of symbols. The research is aimed to obtain structures of transmitter, optimal and sub-optimal receivers using modeling and mathematical analysis of systems including the channel. Furthermore, propose strategies for symbol detection and performance evaluation. Seven strategies of reception to N signals m-QAM non-orthogonal through the AWGN channel. Among the strategies of detection two are optimal and the others five are suboptimal. The two optimal receivers structures presented in this paper are: the classical receiver maximum likelihood (ML) receiver and maximum likelihood based on the Gram-Schmidt decomposition. The suboptimal receivers in this work are of two types: receivers with linear and nonlinear equalization. The first type of receiver is developed based on the criteria of minimum mean square error (MMSE) and the zero forcing (ZF). It is presented the development of analytical design of each linear receiver architectures, as well as determined the error of the estimators. The receivers with nonlinear equalization are based on successive interference cancellation (SIC). In this paper, we propose a modification to the original algorithm of SIC, resulting in a new architecture of equalization. The performance of the proposed receivers is evaluated under different number of carriers and the degree of spectral overlap using computer simulation. Finally, we present the conclusions of this work and future prospects of the research.
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Pérez, Rodenas Ezequiel. "QAM and PSK Modulation Schemes under Impulsive Noise." Thesis, Högskolan i Gävle, Avdelningen för elektronik, matematik och naturvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-11943.
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Nowadays most of the communications systems are designed considering only to work under AWGN (Additive White Gaussian Noise). But the implementation of wireless systems in industrial facilities brings different kind of interference from machines or any other kind of electronic devices. Some of them are sources of randomly and high power noise, which commonly is known as impulsive noise. The objective in this thesis is to study the impact of the impulsive noise on a communication using QAM (Quadrature Amplitude Modulation) and PSK (Phase-Shift Keying) schemes, by observing the BER (Bit Error Rate) and the APD (Amplitude Probability Distribution). For that, it is developed a measurement method that will be used in a real industrial environment in future work. The content of this thesis is divided in two parts. In the first part is made a program in MATLAB to simulate the communication through a noisy channel. Then is developed a measurement method which is tested in three different ways corresponding to 3 different outputs of an spectrum analyzer, namely, 20,4 MHz IF output, video output and IQ data output. The relation of impulsive noise is presented in the second part with different statistical properties in the BER and the APD, in the setup with the best performance. At the end of the thesis a concluding section summarizes the results obtained during the work and some lines of future work in a real industrial environment with the developed method.
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PINTO, ERNESTO LEITE. "PERFORMANCE OF QAM QUATERNARY SYSTEMS IN NONLINEAR CHANNELS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1986. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=9470@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOÉ feito um estudo comparativo de diversos sistemas de modulação digital QAM-4 propostos recentemente na literatura especializada, visando aplicações a canais não lineares. São estabelecidas e implementadas técnicas eficientes para estimação de parâmetros de desempenho destes sistemas, através da simulação em computador. São levantados diversos resultados de desempenho, que possibilitam uma verificação das potencialidades dos sistemas estudados para se reduzir a degradação de performance devido à(s) não linearidade(s) do canal, assim como uma indicação dos sistemas mais eficientes.
Several 4-QM digital modulation systems recently proposed in the literature for application to nonlinear channels are studied and their performances are compared through computer simulation. Efficient techniques to estimate performance parameters from the simulated digital signals are developed and used for extensive computations of power spectrum and error probability degradation even in the presence of adjacent channel interference. The results provide an evaluation of the potential of some new techniques to improve performance in nonlinear channels and also an indication of the most efficient among these techniques.
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Swanson, Richard, Jeff Dimsdle, Tom Petersen, Regina Pasquale, and Roger Bracht. "QAM Multi-path Characterization Due to Ocean Scattering." International Foundation for Telemetering, 2002. http://hdl.handle.net/10150/606308.
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International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, CaliforniaA series of RF channel flight characterization tests were recently run to benchmark multi-path performance of high-speed quadrature amplitude modulation (QAM) over the ocean surface. The modulation format was differential-phase/absolute-amplitude two level polar 16 QAM. The bit rate was 100 Megabits per second with a symbol period of 40nS. An aircraft radiated the test signal at 5 different altitudes. It made two inward flights, on two different days, at each altitude with vertical and horizontal polarization, respectively. Receivers, using circular antenna polarization, were in two different locations. Analysis of the resulting data shows flat fading and frequency selective fading effects.
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Gray, Andrew, Parminder Ghuman, and Scott Hoy. "Multi-Gbps 16-QAM All-Digital Parallel Receiver." International Foundation for Telemetering, 2001. http://hdl.handle.net/10150/607665.
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International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, NevadaDue to rapidly increasing downlink data rates between spacecraft and ground stations, the National Aeronautics and Space Administration (NASA) has developed an all-digital variable data rate receiver. The majority of the receiver is implemented on a single complementary metal oxide semiconductor (CMOS) application specific integrated circuit (ASIC) that is capable of processing data rates in excess of 300 mega-symbols per second or 600 mega-bits per second (Mbps) using quadrature phase-shift keyed (QPSK) modulation [1-5]. Developed jointly by the Goddard Space Flight Center and the Jet Propulsion Laboratory, the high rate digital demodulator (HRDD) ASIC uses parallel processing algorithms, which combined we call the advanced parallel receiver architecture (APRX), to perform the necessary functions of a satellite communications receiver. An overview of the next generation of the advanced parallel receiver architecture (APRX) is presented here, including a new parallel adaptive equalizer currently being implemented. The next generation receiver implementing this architecture will process in excess of 600 Megasymbols per second; the ASIC will process in excess of 1.2 Gbps using quadrature amplitude modulation (QPSK) and 2.4 Gbps using 16-quadrature amplitude modulation (QAM). The majority of the functions of the receiver are performed in the next generation high rate digital demodulator ASIC. A key property of such high data rate wireless communications systems is the use bandwidth efficient modulations often achieved through the use of sophisticated pulseshaping. The next generation ASIC, like the current generation ASIC, is designed to have programmable matched filters. The detection/matched filter bank in the ASIC should be programmed to “match” the received pulse-shape. This is particularly important for good biterror- rate performance in systems employing higher order modulations, such as 16-QAM employing partial-response pulse-shaping spanning many symbols. Such bandwidth efficient pulse-shaping methods require many coefficients in the matched filter; this creates increased computation and complexity in the receiver. Often such ideal receivers are not practical or possible to implement, and sub-optimal detection filtering techniques must be used. We will demonstrate that the use of a sub-optimum or truncated matched filter in some systems introduces severe intersymbol interference (ISI) distortion that results in poor BER results. However, we demonstrate for a specific pulse-shaped 16-QAM that if the demodulated baseband symbols are processed with a relatively simple equalizer very good performance may be achieved. The overall system complexity of such a system may be much lower than implementing the true matched filter [6]. Finally we present an overview of the next generation advanced parallel receiver (APRX) capable of demodulating such pulse-shaped 16-QAM that includes a novel parallel adaptive equalizer.
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Filho, João Mendes. "Algoritmos eficientes para equalização autodidata de sinais QAM." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3142/tde-15032012-122010/.
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Neste trabalho, são propostos e analisados algoritmos autodidatas eficientes para a equalização de canais de comunicação, considerando a transmissão de sinais QAM (quadrature amplitude modulation). Suas funções de erro são construídas de forma a fazer com que o erro de estimação seja igual a zero nas coordenadas dos símbolos da constelação. Essa característica os possibilita ter um desempenho similar ao de um algoritmo de equalização supervisionada como o NLMS (normalized least mean-square), independentemente da ordem da constelação QAM. Verifica-se analiticamente que, sob certas condições favoráveis para a equalização, os vetores de coeficientes dos algoritmos propostos e a correspondente solução de Wiener são colineares. Além disso, usando a informação da estimativa do símbolo transmitido e de seus símbolos vizinhos, esquemas de baixo custo computacional são propostos para aumentar a velocidade de convergência dos algoritmos. No caso do algoritmo baseado no critério do módulo constante, evita-se sua divergência através de um mecanismo que descarta estimativas inconsistentes dos símbolos transmitidos. Adicionalmente, apresenta-se uma análise de rastreio (tracking), que permite obter expressões analíticas para o erro quadrático médio em excesso dos algoritmos propostos em ambientes estacionários e não-estacionários. Através dessas expressões, verifica-se que com sobreamostragem, ausência de ruído e ambiente estacionário, os algoritmos propostos podem alcançar a equalização perfeita, independentemente da ordem da constelação QAM. Os algoritmos são estendidos para a adaptação conjunta dos filtros direto e de realimentação do equalizador de decisão realimentada, levando-se em conta um mecanismo que evita soluções degeneradas. Resultados de simulação sugerem que a utilização dos esquemas aqui propostos pode ser vantajosa na recuperação de sinais QAM, fazendo com que seja desnecessário o chaveamento para o algoritmo de decisão direta.In this work, we propose efficient blind algorithms for equalization of communication channels, considering the transmission of QAM (quadrature amplitude modulation) signals. Their error functions are constructed in order to make the estimation error equal to zero at the coordinates of the constellation symbols. This characteristic enables the proposed algorithms to have a similar performance to that of a supervised equalization algorithm as the NLMS (normalized least mean-square), independently of the QAM order. Under some favorable conditions, we verify analytically that the coefficient vector of the proposed algorithms are collinear with the Wiener solution. Furthermore, using the information of the symbol estimate in conjunction with its neighborhood, we propose schemes of low computational cost in order to improve their convergence rate. The divergence of the constant-modulus based algorithm is avoided by using a mechanism, which disregards nonconsistent estimates of the transmitted symbols. Additionally, we present a tracking analysis in which we obtain analytical expressions for the excess mean-square error in stationary and nonstationary environments. From these expressions, we verify that using a fractionally-spaced equalizer in a noiseless stationary environment, the proposed algorithms can achieve perfect equalization, independently of the QAM order. The algorithms are extended to jointly adapt the feedforward and feedback filters of the decision feedback equalizer, taking into account a mechanism to avoid degenerative solutions. Simulation results suggest that the proposed schemes may be advantageously used to recover QAM signals and make the switching to the decision direct mode unnecessary.
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Jin, Jing. "RS-coded M-QAM transmission techniques for Wireless Communications." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:8881/R/?func=dbin-jump-full&object_id=92363.
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Hederström, Josef. "Construction of FPGA-based Test Bench for QAM Modulators." Thesis, Linköpings universitet, Elektroniska komponenter, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-62243.
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In todays fast evolving mobile communications the requirements of higher datarates are continuously increasing, pushing operators to upgrade the backhaul to support these speeds. A cost eective way of doing this is by using microwave links between base stations, but as the requirements of data rates increase, the capacity of the microwave links must be increased. This thesis was part of a funded research project with the objective of developing the next generation high speed microwave links for the E-band. In the research project there was a need for a testing system that was able to generate a series of test signals with selectable QAM modulations and adjustable properties to be able to measure and evaluate hardware within the research project. The developed system was designed in a digital domain using an FPGA platform from Altera, and had the ability of selecting several types of modulations and changing the properties of the output signals as requested. By using simulation in several steps and measurements of the complete system the functionality was verified and the system was delivered to the research project successfully. The developed system can be used to test several dierent modulators in other projects as well and is easily extended to provide further properties.
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Abdulmajeed, Sabeena. "Analysis of QAM schemes in a CCI-limited environment." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq28839.pdf.
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Brent, Jason B. "Coherent detection of QAM signals in land mobile radio." Thesis, Loughborough University, 1988. https://dspace.lboro.ac.uk/2134/10455.
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This thesis forms part of a joint universities project in which it is required to design and build a digital modem for the transmission of speech or data over a 900MHz land mobile radio channel. The main objectives being to try to maximize the bandwidth efficiency and attain near-optimum system performance. The theoretical modem design is presented here. The other parts of the system, that is the error control coding, speech coding, RF design qnd the actual hardware implementation are described elsewhere. All the systems described here have been designed to satisfy the overall system requirements. In particular, it must be possible to build this modem with existing technology without undue equipment complexity. All aspects of the digital'modem design are addressed, namely the choices of modulation scheme, pulse shaping filtering, packet structure and timing and synchronization methods suitable for the transmission of a digital signal over the fading radio channel. The important problems of channel estimation and data detection are examined in more detail. The first system described is one in which only one digital signal is transmitted in a narrowband channel. In the second system a novel technique of transmitting two signals in the same frequency band from two different mobiles to a single base station is described, which makes use of the fact that these two transmission paths are fading independently. The third system describes a method for transmitting back to these mobiles from the base station, again in the same frequency band. Although these systems have been designed specifically for use over 900MHz cellular land mobile radio channels, the ,techniques described are directly applicable to digital signal transmission over any flat fading channel.
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Wütschner, Georg [Verfasser]. "Robuste Trägerphasensynchronisation für stark gestörte QAM-Signale / Georg Wütschner." Aachen : Shaker, 2005. http://d-nb.info/1186576944/34.
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Zhang, Xu. "Modeling & Performance Analysis of QAM-based COFDM System." University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1310148963.
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Peh, Lin Kiat. "Performance comparison of two implementations of TCM for QAM." Thesis, Monterey, California. Naval Postgraduate School, 2007. http://hdl.handle.net/10945/55202.
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Approved for public release; distribution is unlimited.Trellis-Coded Modulation (TCM) is employed with quadrature amplitude modulation (QAM) to provide error correction coding with no expense in bandwidth. There are two common implementations of TCM, namely pragmatic TCM and Ungerboeck TCM. Both schemes employ Viterbi algorithms for decoding but have different code construction. This thesis investigates and compares the performance of pragmatic TCM and Ungerboeck TCM by implementing the Viterbi decoding algorithm for both schemes with 16-QAM and 64-QAM. Both pragmatic and Ungerboeck TCM with six memory elements are considered. Simulations were carried out for both pragmatic and Ungerboeck TCM to evaluate their respective performance. The simulations were done using Matlab software, and an additive white Gaussian noise channel was assumed. The objective was to ascertain that pragmatic TCM, with its reduced-complexity decoding, is more suitable to adaptive modulation than Ungerboeck TCM.
Civilian
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Araújo, Daniel Costa. "Sistema de comunicações com sinais m-QAM não – ortogonais." reponame:Repositório Institucional da UFC, 2012. http://www.repositorio.ufc.br/handle/riufc/4026.
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ARAÚJO, D. C. Sistema de comunicações com sinais m-QAM não – ortogonais. 2012. 70 f. Dissertação (Mestrado em Teleinformática) - Centro de Tecnologia, Universidade Federal do Ceará, Fortaleza, 2012.Submitted by Marlene Sousa (mmarlene@ufc.br) on 2012-10-31T13:55:48Z No. of bitstreams: 1 2012_dis_dcaraújo.pdf: 2634428 bytes, checksum: 6690780c8f07158809fc79b569af865c (MD5)
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This work presents studies on communication systems, whose signals used for transmission of information are non-orthogonal, overlapping in frequency and carrier spacing less than the rate of symbols. The research is aimed to obtain structures of transmitter, optimal and sub-optimal receivers using modeling and mathematical analysis of systems including the channel. Furthermore, propose strategies for symbol detection and performance evaluation. Seven strategies of reception to N signals m-QAM non-orthogonal through the AWGN channel. Among the strategies of detection two are optimal and the others five are suboptimal. The two optimal receivers structures presented in this paper are: the classical receiver maximum likelihood (ML) receiver and maximum likelihood based on the Gram-Schmidt decomposition. The suboptimal receivers in this work are of two types: receivers with linear and nonlinear equalization. The first type of receiver is developed based on the criteria of minimum mean square error (MMSE) and the zero forcing (ZF). It is presented the development of analytical design of each linear receiver architectures, as well as determined the error of the estimators. The receivers with nonlinear equalization are based on successive interference cancellation (SIC). In this paper, we propose a modification to the original algorithm of SIC, resulting in a new architecture of equalization. The performance of the proposed receivers is evaluated under different number of carriers and the degree of spectral overlap using computer simulation. Finally, we present the conclusions of this work and future prospects of the research.
Este trabalho apresenta estudos sobre sistemas de comunicação cujos sinais utilizados para a transmissão das informações são não-ortogonais, superpostos em frequência, e com espaçamento entre portadoras menor do que a taxa de símbolo. As pesquisas estão direcionadas na obtenção de estruturas de transmissor e receptor ótimos e sub-ótimos, na modelagem e análise matemática dos sistemas incluindo o canal, em propostas de estratégias para detecção de símbolo, e na avaliação de desempenho. São propostas sete estratégias de recepção de N sinais m-QAM não-ortogonais através do canal AWGN. Dentre as estratégias de detecção duas são ótimas e as outras cinco são subótimas. As duas estruturas de receptores ótimos apresentados neste trabalho são: o receptor de máxima verossimilhança (ML) clássico e o receptor de máxima verossimilhança com base na decomposição de Gram-Schmidt. Os receptores sub-ótimos desenvolvidos neste trabalho são de dois tipos: receptores com equalização linear e receptores com equalização não-linear. O primeiro tipo de receptor é desenvolvido com base nos critérios de erro quadrático médio mínimo (MMSE) e o de forçagem a zero (ZF). É apresentado o desenvolvimento analítico do projeto de cada uma das arquiteturas de receptores lineares, assim como é determinado o erro dos estimadores. Os receptores com equalização não-linear são baseados no cancelamento de interferência sucessiva (SIC). Neste trabalho, é proposta uma modificação no algoritmo do SIC original, resultando em uma nova arquitetura de equalização. O desempenho dos receptores propostos é avaliado em diferentes condições de número de portadoras e de grau de superposição espectral através de simulação computacional. Por fim, são apresentados as conlusões e as perspectivas futuras de pesquisa.
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Gomes, Geraldo Gil Raimundo. "Modulação codificada por blocos para constelações M-QAM não quadradas." [s.n.], 1997. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259802.
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Orientador: Renato Baldini FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: A redução da complexidade de decodificação é, provavelmente, uma das principais linhas de pesquisa a respeito de como tornar mais atrativa a utilização de esquemas de modulação codificada por blocos (BCM). Um método para redução da complexidade de decodificação de esquemas M-QAM codificados por blocos foi apresentado por Williams [5]. Este método está fundamentado no fato de que qualquer constelação QAM quadrada pode ser considerada a composição de dois esquemas ASK ortogonais e que cada esquema ASK pode ser codificado por bloco individualmente. Entretanto, o método apresentado por Williams[5] é válido somente para M= ?2 POT. N? onde N é um número par não incluindo, portanto, constelações M-QAM não quadradas. O principal objetivo desta tese é apresentar uma extensão do método proposto por Williams[5] para os esquemas M-QAM não quadrados. Esta tese é dividida basicamente em três partes. Os conceitos fundamentais sobre BCM e suas aplicações a constelações M-QAM, através dos algoritmos de codificação e decodificação propostos por Cusack [2] e Sayegh [3], estão contidos na primeira parte. A segunda parte desenvolve o método de Williams [1] para constelações M-QAM quadradas através da proposta de redução de dimensionalidade. Um conjunto de códigos adequados aos esquemas M-QAM quadrados e seus respectivos ganhos de codificação assintóticos são mostrados, bem como as soluções de Williams [5] para os problemas de sincronização dos blocos e invariância aos deslocamentos de fase... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: The decoding complexity reduction is probably one of the main research topics concerning how to make the use of block coded modulation more attrative. Williams [5] has shown a method to reduce the decoding complexity of a block coded M-QAM scheme. That method has the advantage of the fact that any QAM constellation can be considered as a two orthogonal ASK scheme, and that each ASK scheme can be individually block encoded. However, the Williams' method is valid only for M = ?2 POT. N? where N is an even number not including, therefore, non-square M-QAM. The main purpose of this thesis is to present an extension of the encoding method proposed by Williams [5] for non-square M-QAM. This thesis is basically divided into three parts. The fundamental concepts of block coded modulation and their applications for M-QAM schemes, based on the encoding and decoding algorithms proposed by Cusack [2] and Sayegh [3], are presented in the first part. The second part develops the Williams'method for square M-QAM by using the proposlal of dimensionality reduction. A set of suitable codes for square M-QAM and their respective asymptotic coding gains are shown, as well as the Williams' solutions for block synchronization and phase shift invariance problems. The third part describes two solutions for non-square M-QAM block coded modulation. A set of suitable codes for non-square M-QAM and their respective asymptotic coding gains are shown. Finally, a 32-QAM block coded modulation performance curve obtained by computer simulation is presented.
Mestrado
Mestre em Engenharia Elétrica
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Manso, Rogerio C. "Performance analysis of M-QAM with Viterbi soft-decision decoding." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Mar%5FManso.pdf.
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Terzi, Evren. "Blind synchronization and detection of Nyquist pulse shaped QAM signals." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0002997.
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Miyamoto, Shinichi, Masaaki Katayama, and Norihiko Morinaga. "Performance Analysis of QAM System Under Class A Impulsive Noise Environment." IEEE, 1995. http://hdl.handle.net/2237/7095.
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Gormley, Dylan Jacob. "A Low-Memory Spectral-Correlation Analyzer for Digital QAM-SRRC Waveforms." Cleveland State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=csu1622636550863441.
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Bouras, Dimitri. "Optimal decoding of PSK and QAM signals in frequency nonselective fading channels." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/29927.
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In this thesis, the maximum likelihood sequential decoder for the reception of coded digitally modulated signals with single or multiamplitude constellations transmitted over a multiplicative, frequency nonselective fading (Rayleigh or Rician) channel and corrupted by additive white Gaussian noise (AWGN), is derived. It is shown that its structure consists of a combination of envelope, multiple differential¹ and coherent detectors. The outputs of each of these detectors are jointly processed by means of an algorithm which is presented in a recursive form. The derivation of this new receiver is general enough to accommodate uncoded as well as trellis coded Phase Shift Keying (PSK) and Quadrature Amplitude Modulated (QAM) schemes. Differentially encoded signals, such as the π/4-shift DQPSK scheme which has been selected as the new transmission standard for the emerging all-digital North American and Japanese cellular system, can be also incorporated. Furthermore, there is no assumption made on the power spectral density (or equivalently on the autocorrelation function) of the fading process, although it is considered to be known to the receiver. In order to reduce the overall receiver implementation complexity, several reduced complexity, near optimal versions of the algorithm are presented. These reduced complexity receivers are based on the use of only few multiple differential detectors. Performance evaluation results for reduced complexity trellis coded π/4-shift DQPSK and π/4-shift 8-DQAM systems have demonstrated that the proposed receivers dramatically reduce the error floor occurring due to fading. For example, for the π/4-shift DQPSK scheme operated in a fast (B[formula omitted]T=0.l25) Rayleigh flat-fading channel at a Signal-to-Noise ratio (SNR) of about 25 dB, the new reduced complexity receiver structures result in a bit error rate (BER) reduction of more than three orders of magnitude as compared to a conventional Viterbi receiver. For a slower fading channel, these gains are even higher. What is even more interesting, though, is that this performance was achieved by employing only up to third order multiple differential detectors, thus maintaining reasonable levels of implementation complexity. By further increasing the order of the employed multiple differential detectors, the obtained BER performance improvements were found to be minimal.
To verify experimentally the effectiveness of the proposed receivers and to gain additional insight into some of the real-life implementation problems involved, we designed and realized in hardware a prototype π/4-shift DQPSK modem. Although its transmitter was designed with off the shelf digital TTL chips, linear analog devices and RF modules, its receiver was implemented by means of a TMS320C30 Digital Signal Processor. Employing this "flexible" receiver, the proposed algorithms could be evaluated very efficiently. The various experimental BER results obtained were in excellent agreement with the equivalent results obtained by means of computer simulation.
Motivated by these very encouraging experimental performance results, it is believed that LSI/VLSI implementation of such a π/4-shift DQPSK modem would be a very worthwhile task.
¹ As it will be explained later on, a k[formula omitted] order multiple differential detector is a differential detector employing a k[formula omitted] symbol delay element.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
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Mohammadi, Abbas. "A direct microwave M-QAM adaptive transmitter for fixed wireless ATM networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0012/NQ37899.pdf.
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Haghighat, Afshin. "Low-jitter symbol timing recovery for M-ary QAM and PAM signals." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0002/MQ39476.pdf.
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Gagnon, Ghyslain. "Génération et synchronisation des horloges pour un système micro-ondes 1024 QAM /." Montréal : École de technologie supérieure, 2003. http://wwwlib.umi.com/cr/etsmtl/fullcit?pMQ86826.
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Thèse (M. Ing.)--École de technologie supérieure, Montréal, 2003."Mémoire présenté à l'École de technologie supérieure comme exigence partielle à l'obtention de la maîtrise en génie électrique". Bibliogr.: f. [189]-190. Également disponible en version électronique.
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Gagnon, Ghyslain. "Génération et synchronisation des horloges pour un système micro-ondes 1024 QAM." Mémoire, École de technologie supérieure, 2003. http://espace.etsmtl.ca/762/1/GAGNON_Ghyslain.pdf.
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Un récepteur QAM doit échantillonner le signal modulé reçu une fois par symbole. L'échantillonnage doit se faire au moment idéal, au centre de "l'oeil". Lorsque du bruit de phase corrompt les horloges à l'émetteur et au récepteur, l'oeil apparaît plus fermé, dégradant les performances théoriques du système de communication. Les systèmes QAM à haut niveau sont très sensibles au bruit de phase sur les horloges.
Ce mémoire propose un système de génération et synchronisation des horloges adapté aux communications QAM à haut niveau, minimisant le bruit de phase. Le système est basé sur deux boucles à verrouillage de phase numériques. La boucle à l'émetteur contient un diviseur de fréquence fractionnaire par conversion sigma-delta afin d'obtenir une bonne résolution de la fréquence en sortie sans sacrifier la largeur de bande de la boucle. La boucle au récepteur comporte un préfiltre numérique de mise en forme du signal minimisant le bruit de phase généré par la boucle.
Le circuit de génération d'horloge a été entièrement réalisé sur une plateforme de développement avec FPGA. Le spectre théorique du bruit de phase de ce circuit est d'abord calculé en prenant en considération chaque source de bruit. Les calculs théoriques sont comparés aux spectres relevés en pratique, confirmant la validité des équations développées dans ce travail.
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Fernandes, Diogo. "Low-cost implementation techniques for generic square and cross M-QAM constellations." Universidade Federal de Juiz de Fora, 2015. https://repositorio.ufjf.br/jspui/handle/ufjf/1555.
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CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico
Este trabalho tem como objetivo apresentar técnicas com complexidade computacional reduzida para implementação em hardware do modulador de amplitude em quadratura M-ária (M-ary quadrature amplitude modulation - M-QAM) de elevada ordem, que pode ser viável para sistemas banda larga. As técnicas propostas abrangem as constelações M-QAM quadradas e cruzadas (número par e ímpar de bits), a regra de decisão abrupta (hard decison rule), derivação de constelações M-QAM de baixa ordem das de elevada ordem. A análise de desempenho em termos de taxa de bits errados (bit error rate - BER) é realizada quando os símbolos M-QAM são corrompidos por ruído Gaussiano branco aditivo (additive white Gaussian noise - AWGN) e ruído Gaussiano impulsivo aditivo (additive impulsive Gaussian noise - AIGN). Os resultados de desempenho da taxa de bits errados mostram que a perda de desempenho das técnicas propostas é, em média, inferior a 1 dB, o que é um resultado surpreendente. Além disso, a implementação das técnicas propostas em arranjo de portas programáveis em campo (field programmable gate array - FPGA) é descrita e analisada. Os resultados obtidos com as implementações em dispositivo FPGA mostram que as técnicas propostas podem reduzir consideravelmente a utilização de recursos de hardware se comparadas com as técnicas presentes na literatura. Uma melhoria notável em termos de redução da utilização de recursos de hardware é conseguida através da utilização da técnica de modulação M-QAM genérica em comparação com a técnica de regra de decisão heurística (heuristic decision rule - HDR) aprimorada e uma técnica previamente concebida, a tà c cnica HDR. Com base nas análises apresentadas, a técnica HDR aprimorada é menos complexa do que a técnica HDR. Finalmente, os resultados numéricos mostram que a técnica de modulação M-QAM genérica pode ser oito vezes mais rápida do que as outras duas técnicas apresentadas, quando um grande número de símbolos M-QAM (p. ex., > 1000) são transmitidos consecutivamente.
This work aims at introducing techniques with reduced computational complexity for hardware implementation of high order M-ary quadrature amplitude modulation (MQAM) which may be feasible for broadband communication systems. The proposed techniques cover both square and cross M-QAM constellations (even and odd number of bits), hard decision rule, derivation of low-order M-QAM constellations from high order ones. Performance analyses, in terms of bit error rate (BER) is carried out when the M-QAM symbols are corrupted by either additive white Gaussian noise (AWGN) or additive impulsive Gaussian noise (AIGN). The bit error rate performance results show that the performance loss of the proposed techniques is, on average, less than 1 dB, which is a remarkable result. Additionally, the implementation of the proposed techniques in field programmable gate array (FPGA) device is described and outlined. The results based on FPGA show that the proposed techniques can considerably reduce hardware resource utilization. A remarkable improvement in terms of hardware resource utilization reduction is achieved by using the generic M-QAM technique in comparison with the enhanced heuristic decision rule (HDR) technique and a previously designed technique, the HDR technique. Based on the analyses performed, the enhanced HDR technique is less complex than the HDR technique. Finally, the numerical results show that the generic M-QAM technique can be eight times faster than the other two techniques when a large number of M-QAM symbols (e.g., > 1000) are consecutively transmitted.
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Tariq, Muhammad Fahim. "An investigation into pilot aided channel adaptive modems for narrowband wireless data communications." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326692.
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Assegu, Wannaw, and Ibrahim Fofanah. "Performance of Coded 16-QAM OFDM Modulation with Equalizer Over an Aeronautical Channel." International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595639.
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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, NevadaThe main objectives of iNET (Integrated Network Enhanced Telemetry) are increased data rate and improved spectral efficiency [1]. In this paper we propose that transmission scheme for the physical layer is coded 16-QAM OFDM (Quadrature Amplitude Modulation-Orthogonal Frequency Division Multiplexing) which enables high data rate and spectrum efficiency. However in high mobility scenarios, where the channel is time-varying the receiver design is more challenging. Therefore in this paper pilot-assisted channel estimation is used at the receiver, with convolutional coding and error correction to enhance the performance; while the effect of inter symbol interference (ISI) is mitigated by cyclic prefix. The focus of this paper is to evaluate the performance of OFDM with 16-QAM over an aeronautical channel. The 16-QAM with OFDM enables 4 bits/symbol and provides a higher data rate than QPSK hence it is chosen in this paper. The implementation of OFDM is done using Inverse Fast Fourier Transform (IFFT) and the Fast Fourier Transform (FFT). In this paper we simulate how the performance of Coded 16-QAM OFDM is enhanced using equalization to compensate for inter symbol interference, convolutional coding is used for error correction, puncturing for improving data rate and the insertion of cyclic prefix (CP) to avoid inter carrier interference.
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Pham, Edward Carleton University Dissertation Engineering Electrical. "SER prediction for transmission of PSAM 16-QAM in frequency selective fading channels." Ottawa, 1992.
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黃敏瑞. "16 QAM Modulator." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/22479213068708945467.
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碩士國立中央大學
電機工程研究所
89
Because people need more and more service in wireless communication，so we have to raise our frequency to fit these requirement。For example，DTV(digital television ) is a kind of system that uses 28GHz in wireless communication，and it has many channels in 50MHz~900MHZ，each channel has 6MHZ data rate。The modulator for DTV is 16 QAM，and aspect of this thesis is 16 QAM modulator。 We use a chip is analog device AD9853，for this purpose，It's Function include : Preamble ， Reed-Solomom Encoder，Randomizer，16 QAM Modulation and FIR Digital Filter。We setup it according to its and program it by I2C communication algorithm which uses PIC(peripheral interface controller) and parallel port to implement 。
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Wang, Hsi-Hua, and 王熙華. "Noncoherent Block-Coded QAM." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/wppzze.
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碩士國立中央大學
通訊工程研究所
94
A novel block coded modulation scheme for noncoherent detection, called noncoherent block-coded MPSK (NBC-MPSK) was proposed recently. Besides, uncoded quadrature amplitude modulation (QAM) with energy constraint methods have been proposed in 2002 and 2005, which have better error performance than uncoded MPSK with the same high data rate. In this thesis, we extend NBC-MPSK to noncoherent block-coded QAM (NBC-QAM). We find out the appropriate ratio of inner and outer radius by the analysis and simulations. Compared with NBC-MPSK, NBC-QAM has larger minimum noncoherent distance and therefore better error performance. We also show that QAM with the energy constraint method proposed in 2005 can be viewed as a special case of NBC-QAM. But in our NBC-QAM scheme, minimum noncoherent distance of QAM can be further enlarged by using more redundant bits.
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Petit, Paul. "Turbo-equalization for QAM constellations." 2002. http://arrow.unisa.edu.au:8081/1959.8/46699.
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While the focus of this work is on turbo equalization, there is also an examination of equalization techniques including MMSE linear and DFE equalizers and Precoding. The losses and capacity associated with the ISI channel are also examined. Iterative decoding of concatenated codes is briefly reviewed and the MAP algorithm is explained.
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"Multiple trellis coded 16 QAM." Chinese University of Hong Kong, 1994. http://library.cuhk.edu.hk/record=b5888189.
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by Kingsley, King-chi, Kwan.Thesis (M.Phil.)--Chinese University of Hong Kong, 1994.
Includes bibliographical references (leaves 85-88).
Tables of Contents
Lists of Figures & Tables
Acknowledgments
Abstract
Chapter Chapter 1 --- Introduction
Chapter 1.1 --- Digital Communication System --- p.P. 1
Chapter 1.2 --- Channel Coding --- p.P. 1
Chapter 1.3 --- Convolution Encoder --- p.P. 4
Chapter 1.4 --- Additive White Gaussian Noise (AWGN) Channel --- p.P. 7
Chapter 1.5 --- Trellis Diagram --- p.P. 8
Chapter 1.6 --- Error Event and Free Distance --- p.P. 8
Chapter 1.7 --- Euclidean Distance --- p.P. 10
Chapter 1.8 --- Organization of the Thesis --- p.P. 11
Chapter Chapter 2 --- QAM and MTCM
Chapter 2.1 --- Introduction --- p.P. 13
Chapter 2.2 --- M-ary Quadrature Amplitude Modulation (QAM)
Chapter 2.2.1 --- M-ary Digital Modulation --- p.P. 13
Chapter 2.2.2 --- Quadrature Amplitude Modulation (QAM) --- p.P. 14
Chapter 2.2.3 --- Probability of Bit Error of M-ary QAM --- p.P. 16
Chapter 2.3 --- Trellis Coded Modulation (TCM) --- p.P. 17
Chapter 2.4 --- Multiple Trellis Coded Modulation (MTCM) --- p.P. 19
Chapter Chapter 3 --- Set Partitioning of Signal Sets
Chapter 3.1 --- Introduction --- p.P. 21
Chapter 3.2 --- Traditional Set Partitioning Methods
Chapter 3.2.1 --- Ungerboeck's Set Partitioning Method --- p.P. 21
Chapter 3.22 --- Set Partitioning by M.K. Simon and D. Divsalvar --- p.P. 23
Chapter 3.3 --- The new Set Partitioning Method
Chapter 3.3.1 --- Nomenclature of the Signal Points in the Signal Constellations --- p.P. 24
Chapter 3.3.2 --- Generation of the Signal Sets --- p.P. 26
Chapter 3.3.3 --- Partitioning of the Signal Sets
Chapter 3.3.3.1 --- Input Constraints of the Partitioning Method --- p.P. 30
Chapter 3.3.3.2 --- The Set Partitioning Method --- p.P. 30
Chapter 3.3.4 --- Distance Properties of the Partitioned Signal Sets --- p.P. 36
Chapter 3.3.5 --- The Selection Scheme --- p.P. 39
Chapter 3.3.6 --- Assignment of Signal Subsets into Trellis --- p.P. 42
Chapter Chapter 4 --- Performance Evaluation
Chapter 4.1 --- Introduction --- p.P. 46
Chapter 4.2 --- Upper Bound of Error Probability
Chapter 4.2.1 --- Probability of Symbol Error --- p.P. 46
Chapter 4.2.1.1 --- Upper Bound on Probability of Symbol Error --- p.P. 48
Chapter 4.2.1.2 --- Computation of the Transfer Function --- p.P. 49
Chapter 4.2.2 --- Probability of Bit Error --- p.P. 51
Chapter 4.3 --- Computation of the Free Distance --- p.P. 53
Chapter Chapter 5 --- Results Presentation and Discussions
Chapter 5.1 --- Introduction --- p.P. 58
Chapter 5.2 --- Results Presentations
Chapter 5.2.1 --- Normalized Square Free Euclidean Distance --- p.P. 58
Chapter 5.2.2 --- Error Probability --- p.P. 71
Chapter 5.3 --- Discussions --- p.P. 77
Chapter Chapter 6 --- Conclusions --- p.P. 83
Bibliography --- p.P. 85
Chapter Appendix A - --- Flowchart of the Program --- p.P. 89
Chapter Appendix B - --- Tabulated Results of d2free --- p.P. 104
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Tzeng, Jonq-Yau, and 曾重堯. "Computer Simulation on 64-QAM CATV Modem and the Implementation of a 64-QAM Transmitter." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/48531414326568526322.
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Zeng, Zhong-Yao, and 曾重堯. "COMOUTER SIMULATION ON 64-QAM CATV MODEM AND THE IMPLEMENTATION OF A 64-QAM TRANSMITTER." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/37482986130591137513.
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Zhang, Dongpeng. "Digital Signal Processing of POL-QAM and SP-QAM in Long-Haul Optical Transmission Systems." Thesis, 2014. http://spectrum.library.concordia.ca/978290/1/Zhang_MASc_S2014.pdf.
Full textAbstract:
Coherent detection employing high modulation formats has become one of the most
attractive technologies for long-haul transmission systems due to the high power and
spectral efficiencies. Appropriate digital signal processing (DSP) is used to equalize and
compensate for distortion caused by laser and fiber characteristics and impairments, such
as polarization mode dispersion (PMD), polarization rotation, laser phase noise and
nonlinear effects. Research on the various DSP algorithms in the coherent optical
communication systems is the most promising investigation.
In this research, two new modulation formats; polarization QAM modulation (POL-QAM)
and set-partitioning QAM (SP-QAM) are investigated due to their high spectral
efficiency and novelty. For PMD and polarization rotation equalization, a new modified
constant modulus algorithm (CMA) is proposed for POL-QAM. We investigate the bit
error rate (BER) performance of the two modulation formats over fiber channel
considering PMD and polarization rotation effects. Furthermore, we investigate the BER
performance of the two modulation formats over long-haul fiber optic transmission
systems. Carrier phase estimation (CPE) algorithms are also investigated, which are used
to mitigate phase noise caused by the transmitter.
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Qiu, Zhao Lan, and 邱昭嵐. "The implementation of 64 QAM transmitter." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/84623408774146789487.
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Lee, Yu-Min, and 李育民. "Blind Equalization for High Order QAM." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/58841307523330372725.
Full textAbstract:
碩士國立交通大學
電信研究所
81
In terrestial digital radio systems,the use of adaptive equalizers to combat with multipath distortion is desired. Conventional equalization techniques require that a training sequence known to the receiver is sent periodically such that the equalizer can determine the inverse channel transfer function via a deconvolution procedure. This kind of processing can be costly and may not be achievable in many applications such as multi-point networks. The desirability of avoiding the difficulty of the training sequence driven process prompts the development of a class of blind equalizers which achieve parameter estimation based on the channel output and prior knowledge about the input sequence. In this thesis,we propose a blind equalizer whose operation is based on the minimization of a noncovex cost function derived from the geometric and statistical properties of the QPSK constellation. Extension of the proposed method to QAM signals is straightforward with a minor modification of the cost function. Simulation results demonstrate that the proposed method achieves the performance of Godard's method for modreate channel conditions, and outperforms the latter for high order QAM signals. A merit of the proposed method not shared by Godard's is that it is immune to the random phase error incurred with the channel distortion. As a preliminary trial, We also incorporate spatial domain processing via an adaptive array to further improve the performance of the equalizer. The convergence property of the proposed algorithm is analyzed mathematically and confirmed by computer simulations.
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Chang, Chung-Yi, and 張仲逸. "16- and 64-QAM Golay Complementary Sequences." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/12641478786788247542.
Full textAbstract:
碩士元智大學
通訊工程學系
96
Golay complementary sequences have the property that the sum of aperiodic auto-correlation functions for pairing sequences is an impulse function. There exist constructions of H-PSK, 16-QAM, and 64-QAM Golay sequences of length n??2m. In 1999 Davis and Jedwab gave a direct construction for H-PSK Golay sequences known as “GDJ Golay sequences.” 16- and 64-QAM Golay sequences can be constructed as the weighted sum of two or three QPSK GDJ Golay sequences differing by an offset or an offset pair. The combinations of offsets is the core in the description of QAM Golay sequence constructions. In 2007, Li modified previous constructions of 16- and 64-QAM Golay sequences, and proposed two cases of new offset pairs in a conjecture. These offset pairs can be used to construct additional new 64-QAM Golay sequences. In this thesis, we first present the proof for the new construction of 64-QAM Golay sequences. There are no intersections between the 64-QAM Golay sequences produced by the new construction and the original construction. When the sequence length is very long, the new construction yields more 64-QAM Golay sequences compare to the original construction. Secondly, we study the pairing sequences for 16- and 64-QAM Golay sequences of length n ?d 4. The number of pairing sequences for each 16-QAM Golay sequence is 8 or 16, and is determined by the offset. The number of pairing sequences for each 64-QAM Golay sequence is 8, 16, or 24, and is determined by the offset pair. We demonstrate how the number of pairing sequences can be determine by the offset or offset pair, and give the constructions and enumerations of 16- and 64-QAM Golay pairs where the pairing sequences are consisted of QPSK Golay sequences in the same Golay coset.
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Meintrup, David [Verfasser]. "Soft-Decodierung für QAM-modulierte Signale / David Meintrup." 2003. http://d-nb.info/966280776/34.
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