Southern U.S. teachers at suburban high schools can use Edmodo; however, teachers prefer traditional teacher-centered teaching methods. This quantitative correlative study explored teachers' technology acceptance in relation to teaching styles and experiences. Framing acceptance by Davis's technology acceptance model (TAM), research questions addressed the direct and moderating relationships between teaching style and the TAM variables related to using Edmodo and the direct and moderating relationships between teaching experiences and TAM variables. From 240 teachers at the high school, 45 completed an online survey (response rate of 18.75%). Descriptive statistics, ANOVA, and regression analyzed data. TAM could be verified for the entire sample; however, no significant direct relationship between teaching style and the TAM variables was found. Teaching style moderated the relationships within the TAM; these were stronger for teachers with a teacher-centered teaching style. No significant direct relationship existed between teaching experiences and TAM variables; a moderating effect on the relationships existed within the TAM. Among experienced teachers, ease of use was the strongest acceptance predictor, whereas perceived use was the strongest predictor among less experienced teachers. Results indicated teachers might develop a more student-centered teaching style, thus concentrating on technology's ease of use, rather than its potential utility. A policy recommendation could ensure teachers efficiently used technology to support student-centered learning. The application of the recommended policies might lead to teachers' more effective use of instructional technology, which might affect student learning and motivation.

There is a growing demand for the high quality TV programs such as High Definition TV (HDTV). The CATV network is often a suitable solution to address this demand using a CATV modem delivering high data rate digital signals in a cost effective manner, thereby, utilizing a complex digital modulation scheme is inevitable. Exploiting complex modulation schemes, entails a more sophisticated modulator and distribution system with much tighter tolerances. However, there are always distortions introduced to the modulated signal in the modulator degrading signal quality.<p> In this research, the effect of distortions introduced by the RF band pass filter in the modulator will be considered which cause degradations on the quality of the output Quadrature Amplitude Modulated (QAM) signal. Since the RF filter's amplitude/group delay distortions are not symmetrical in the frequency domain, once translated into the base band they have a complex effect on the QAM signal. Using Matlab, the degradation effects of these distortions on the QAM signal such as Bit Error Rate (BER) is investigated.<p> In order to compensate for the effects of the RF filter distortions, two different methods are proposed. In the first method, a complex base band compensation filter is placed after the pulse shaping filter (SRRC). The coefficients of this complex filter are determined using an optimization algorithm developed during this research. The second approach, uses a pre-equalizer in the form of a Feed Forward FIR structure placed before the pulse shaping filter (SRRC). The coefficients of this pre-equalizer are determined using the equalization algorithm employed in a test receiver, with its tap weights generating the inverse response of the RF filter. The compensation of RF filter distortions in base band, in turn, improves the QAM signal parameters such as Modulation Error Ratio (MER). Finally, the MER of the modulated QAM signal before and after the base band compensation is compared between the two methods, showing a significant enhancement in the RF modulator performance.

There is a growing demand for the high quality TV programs such as High Definition TV (HDTV). The CATV network is often a suitable solution to address this demand using a CATV modem delivering high data rate digital signals in a cost effective manner, thereby, utilizing a complex digital modulation scheme is inevitable. Exploiting complex modulation schemes, entails a more sophisticated modulator and distribution system with much tighter tolerances. However, there are always distortions introduced to the modulated signal in the modulator degrading signal quality.<p> In this research, the effect of distortions introduced by the RF band pass filter in the modulator will be considered which cause degradations on the quality of the output Quadrature Amplitude Modulated (QAM) signal. Since the RF filter's amplitude/group delay distortions are not symmetrical in the frequency domain, once translated into the base band they have a complex effect on the QAM signal. Using Matlab, the degradation effects of these distortions on the QAM signal such as Bit Error Rate (BER) is investigated.<p> In order to compensate for the effects of the RF filter distortions, two different methods are proposed. In the first method, a complex base band compensation filter is placed after the pulse shaping filter (SRRC). The coefficients of this complex filter are determined using an optimization algorithm developed during this research. The second approach, uses a pre-equalizer in the form of a Feed Forward FIR structure placed before the pulse shaping filter (SRRC). The coefficients of this pre-equalizer are determined using the equalization algorithm employed in a test receiver, with its tap weights generating the inverse response of the RF filter. The compensation of RF filter distortions in base band, in turn, improves the QAM signal parameters such as Modulation Error Ratio (MER). Finally, the MER of the modulated QAM signal before and after the base band compensation is compared between the two methods, showing a significant enhancement in the RF modulator performance.

With the development of VLSI and wireless communication technology, portable devices such as personal digital assistants (PDAs), pocket PCs, and mobile phones have gained a lot of popularity. Many such devices incorporate a speech recognition engine, enabling users to interact with the devices using voice-driven commands and text-to-speech synthesis. The power consumption of DSP microprocessors has been consistently decreasing by half about every 18 months, following Gene's law. The capacity of signal processing, however, is still significantly constrained by the limited power budget of these portable devices. In addition, analog-to-digital (A/D) converters can also limit the signal processing of portable devices. Many systems require very high-resolution and high-performance A/D converters, which often consume a large fraction of the limited power budget of portable devices. The proposed research develops a low-power audio signal enhancement system that combines programmable analog signal processing and traditional digital signal processing. By utilizing analog signal processing based on floating-gate transistor technology, the power consumption of the overall system as well as the complexity of the A/D converters can be reduced significantly. The system can be used as a front end of portable devices in which enhancement of audio signal quality plays a critical role in automatic speech recognition systems on portable devices. The proposed system performs background audio noise suppression in a continuous-time domain using analog computing elements and acoustic echo cancellation in a discrete-time domain using an FPGA.

¡@¡@Pseudo-noise (PN) code synchronizer is an essential element of direct-sequence code division multiple access (DS-CDMA) system because data transmission is possible only after the receiver accurately synchronizes the locally generated PN code with the incoming PN code. The code synchronization is processed in two steps, acquisition and tracking, to estimate the delay offset between the two codes. Recently, the adaptive LMS filtering scheme has been proposed for performing both code acquisition and tracking with the identical structure, where the LMS algorithm is used to adjust the FIR filter taps to search for the value of delay-offset adaptively. A decision device is employed in the adaptive LMS filtering scheme as a decision variable to indicate code synchronization, hence it plays an important role for the performance of mean acquisition time (MAT). In this thesis, only code acquisition is considered. ¡@¡@In this thesis, a new decision device, referred to as the weight vector square norm (WVSN) test method, is devised associated with the adaptive LMS filtering scheme for code acquisition in DS-CDMA system. The system probabilities of the proposed scheme are derived for evaluating MAT. Numerical analyses and simulation results verify that the performance of the proposed scheme, in terms of detection probability and MAT, is superior to the conventional scheme with mean-squared error (MSE) test method, especially when the signal-to-interference-plus-noise ratio (SINR) is relatively low. ¡@¡@Furthermore, an efficient and joint-adaptation code acquisition scheme, i.e., a smart antenna coupled with the proposed adaptive LMS filtering scheme with the WVSN test method, is devised for applying to a base station, where all antenna elements are employed during PN code acquisition. This new scheme is a process of PN code acquisition and the weight coefficients of smart antenna jointly and adaptively. Numerical analyses and simulation results demonstrate that the performance of the proposed scheme with five antenna elements, in terms of the output SINR, the detection probability and the MAT, can be improved by around 7 dB, compared to the one with single antenna case.

Effort to estimate unknown time-varying channels as a part of high-speed mobile communication systems is of interest especially for next-generation wireless systems. The high computational complexity of the optimal Wiener estimator usually makes its use impractical in fast time-varying channels. As a powerful candidate, the adaptive least mean squares (LMS) algorithm offers a computationally efficient solution with its simple first-order weight-vector update equation. However, the performance of the LMS algorithm deteriorates in time-varying channels as a result of the eigenvalue disparity, i.e., spread, of the input correlation matrix in such chan nels. In this work, we incorporate the L MS algorithm into the well-known bidirectional processing idea to produce an extension called the bidirectional LMS. This algorithm is shown to be robust to the adverse effects of time-varying channels such as large eigenvalue spread. The associated tracking performance is observed to be very close to that of the optimal Wiener filter in many cases and the bidirectional LMS algorithm is therefore referred to as near-optimal. The computational complexity is observed to increase by the bidirectional employment of the LMS algorithm, but nevertheless is significantly lower than that of the optimal Wiener filter. The tracking behavior of the bidirectional LMS algorithm is also analyzed and eventually a steady-state step-size dependent mean square error (MSE) expression is derived for single antenna flat-fading channels with various correlation properties. The aforementioned analysis is then generalized to include single-antenna frequency-selective channels where the so-called ind ependence assumption is no more applicable due to the channel memory at hand, and then to multi-antenna flat-fading channels. The optimal selection of the step-size values is also presented using the results of the MSE analysis. The numerical evaluations show a very good match between the theoretical and the experimental results under various scenarios. The tracking analysis of the bidirectional LMS algorithm is believed to be novel in the sense that although there are several works in the literature on the bidirectional estimation, none of them provides a theoretical analysis on the underlying estimators. An iterative channel estimation scheme is also presented as a more realistic application for each of the estimation algorithms and the channel models under consideration. As a result, the bidirectional LMS algorithm is observed to be very successful for this real-life application with its increased but still practical level of complexity, the near-optimal tracking performa nce and robustness to the imperfect initialization.

In the Internet era, more and more courses are taught through a course management system (CMS) or learning management system (LMS). In an asynchronous virtual learning environment, an instructor has the need to beware the progress of discussions in forums, and may intervene if ecessary in order to facilitate students¡¦ learning. This research proposes a discussion forum activity flow tracking system, called FAFT (Forum Activity Flow Tracer), to utomatically monitor the discussion activity flow of threaded forum postings in CMS/LMS. As CMS/LMS is getting popular in facilitating learning activities, the proposedFAFT can be used to facilitate instructors to identify students¡¦ interaction types in discussion forums. FAFT adopts modern data/text mining techniques to discover the patterns of forum discussion activity flows, which can be used for instructors to facilitate the online learning activities. FAFT consists of two subsystems: activity classification (AC) and activity flow discovery (AFD). A posting can be perceived as a type of announcement, questioning, clarification, interpretation, conflict, or assertion. AC adopts a cascade model to classify various activitytypes of posts in a discussion thread. The empirical evaluation of the classified types from a repository of postings in earth science on-line courses in a senior high school shows that AC can effectively facilitate the coding rocess, and the cascade model can deal with the imbalanced distribution nature of discussion postings. AFD adopts a hidden Markov model (HMM) to discover the activity flows. A discussion activity flow can be presented as a hidden Markov model (HMM) diagram that an instructor can adopt to predict which iscussion activity flow type of a discussion thread may be followed. The empirical results of the HMM from an online forum in earth science subject in a senior high school show that FAFT can effectively predict the type of a discussion activity flow. Thus, the proposed FAFT can be embedded in a course management system to automatically predict the activity flow type of a discussion thread, and in turn reduce the teachers¡¦ loads on managing online discussion forums.

Τα τελευταία χρόνια η αυξανόμενη σημασία της πληροφορίας και της συνεχιζόμενης μάθησης έχει καταστήσει τη χρήση των τεχνολογιών πληροφορικής και επικοινωνιών (Τ.Π.Ε.) στην εκπαίδευση καθώς και την εξ αποστάσεως εκπαίδευση μέσω e-learning συστημάτων, ως επιτακτική ανάγκη. Το κυριότερο πλεονέκτημα των e-learning συστημάτων είναι ότι παρέχουν τη δυνατότητα στον κόσμο να παρακολουθήσει ένα μάθημα, ακόμα κι ένα ολόκληρο πρόγραμμα σπουδών εξ αποστάσεως, μέσω της σύγχρονης και παγκοσμίως πλέον διαδεδομένης μεθόδου των online courses. Τα περισσότερα μεγάλης εμβέλειας και αναγνωρισιμότητας, πανεπιστήμια του εξωτερικού προσφέρουν online μαθήματα μέσω τεχνολογιών του διαδικτύου, χρησιμοποιώντας διαφάνειες, βιντεο-διαλέξεις και online εκπαιδευτικές δραστηριότητες. Ένας τομέας όμως στον οποίο υστερεί η εκπαίδευση εξ αποστάσεως, ακόμα και στα πιο πρόσφατα ανεπτυγμένα e-learning συστήματα, είναι ο τομέας της προσωποποίησης του σπουδαστή και εξατομίκευσης του συστήματος στις ανάγκες του. Η παρούσα διπλωματική εργασία παρουσιάζει τις δυνατότητες που παρέχονται από τα ήδη υπάρχοντα συστήματα e-learning, την τωρινή κατάσταση με τα παρεχόμενα online μαθήματα από πανεπιστήμια του εξωτερικού και το ερευνητικό κενό που υπάρχει σχετικά με την «προσωποποίηση» (personalization) του σπουδαστή και την προσαρμογή (adaptation) του συστήματος στις ανάγκες του. Μελετάται η μοντελοποίηση του χρήστη (user modeling), τα μαθησιακά προφίλ, ο εμπλουτισμός του προφίλ του σπουδαστή ώστε να παρέχει περισσότερες και αξιόλογες πληροφορίες, καθώς και οι δυνατότητες εξατομίκευσης του συστήματος στον εκάστοτε σπουδαστή, ώστε να επιτευχθεί η επιτάχυνση και αποτελεσματικότητα της ηλεκτρονικής μάθησης. Στα πλαίσια της παρούσας διπλωματικής εργασίας σχεδιάστηκε και υλοποιήθηκε ένα σύστημα ηλεκτρονικής μάθησης, το οποίο στηρίζεται στο λογισμικό Moodle και έχουν αναπτυχθεί σε αυτό, νέες υπηρεσίες εξατομίκευσης και προσαρμοστικότητας του συστήματος στις ανάγκες και προτιμήσεις του εκπαιδευομένου. Το Moodle LMS (Modular Object Oriented Dynamic Learning Environment) είναι ελεύθερο λογισμικό διαχείρισης εκπαιδευτικού περιεχομένου και χρησιμοποιείται από πολλά πανεπιστήμια παγκοσμίως. Είναι ευέλικτο, εύκολο στην εκμάθηση και αρκετά ασφαλές για την ασύγχρονη εκπαίδευση από απόσταση. Ενσωματώνει πληθώρα λειτουργιών και δυνατοτήτων που επιτρέπουν στο διδάσκοντα να διαμορφώσει ένα καλά οργανωμένο και ευχάριστο μάθημα με ευρεία κλίμακα δραστηριοτήτων. Στο εξατομικευμένο και προσαρμοστικό σύστημα ηλεκτρονικής μάθησης που αναπτύχθηκε, διαμορφώθηκε ένα μάθημα με πλούσιο εκπαιδευτικό υλικό, το οποίο απαρτίζουν πολλά και διαφορετικού τύπου μαθησιακά αντικείμενα (πηγές πληροφόρησης, δραστηριότητες, κ.α.). Εμπλουτίστηκε το προφίλ χρήστη με περισσότερες προσωπικές πληροφορίες γι αυτόν και στη συνέχεια αναπτύχθηκαν μαθησιακά μονοπάτια που στηρίζονται είτε στα πεδία προφίλ χρήστη, είτε στο μαθησιακό στυλ του εκπαιδευομένου, είτε σε άλλους παράγοντες που παρουσιάζονται αναλυτικά στην εργασία. Για την εξατομίκευση του συστήματος αναπτύχθηκε μία ενότητα «Pre-course test» η οποία περιλαμβάνει δύο νέες υπηρεσίες για την άντληση πληροφοριών του χρήστη, μορφωτικό υπόβαθρο, μαθησιακό στυλ, προηγούμενη γνώση στο αντικείμενο του μαθήματος κ.α. Τα αποτελέσματα που προκύπτουν από εκεί, αξιοποιούνται κατάλληλα για τη διαμόρφωση ομάδων των εκπαιδευομένων και για τις υπηρεσίες προσαρμοστικότητας του συστήματος. Επίσης, στο διαδικτυακό αυτό σύστημα ηλεκτρονικής μάθησης έχουν αναπτυχθεί μαθησιακά αντικείμενα που ενισχύουν στη συνεργατική μάθηση, βελτιώνουν την ποιότητα του μαθήματος και έτσι αυξάνεται το κίνητρο του σπουδαστή. / Nowdays, e-learning environments have become increasingly popular in educational establishments. The rapid growth of e-learning has changed traditional learning behavior and presented a new situation to both educators (lecturers) and learners (students). The majority of current e-learning systems are based on Learning Management Systems (LMS), which allow students attending courses free from space and time limitations. They can attend the class anytime they are available and regardless of the place. LMS are web-based educational systems that offer students an active role in their own education through a variety of learning activities and different kinds of learning content, that the educator has produced. Although this fact, most Learning Management Systems lack of personalization and adaptivity features. The modern trend in education is the production and organization of Massive Open Online Courses (MOOCs) from large and internationally recognized Universities. So, they focus on gathering too many people in these courses (MOOCs) and not on personalization and adaptivity. Personalization in web-based systems means “attention to the user and his needs”. Web-based systems, such as e-commerce sites, focus on personalization by observing the user, his common actions and navigation paths, in order to understand his preferences and what he is looking for. So they differentiate each individual according to his interests, preferences, and generally his “profile”. Then, they adapt the content appropriately to his needs, and the user watches first the content that may interest him. Traditional and commonly used e-learning platforms offer to their users same educational content, same learning activities and possibilities, and generally exactly the same content, with no further personalization support. Some existing open source e-Learning systems may support, under certain circumstances adaptation and personalization features, but need extension and elaboration to acquire sufficiently these characteristics. Especially in the case of distance learning, that teacher and students have no face-to-face communication, learner’s personalization is essential in order the teacher to be aware of each learner’s characteristics. In e-learning systems, personalization could be achieved with an integrated user profile (student profile), which would include except from the classic information (name, surname, email) more specific and useful information. If the teacher had more information about each student, he could be able to guide him more effectively and evaluate him more correctly. In addition to that, if teacher was aware of each learner’s profile, meaning his learning style, interests, preferences and his previous knowledge of the course topics, he would be able to adapt the learning content to his needs. That would increase student’s satisfaction, motivation and consequently his participation in the course. In this master thesis, a personalized and adaptive e-learning system has been developed. The development of this integrated personalized e-learning system, is based on a very popular open source LMS, which in this case is used for further extension and development of new features. The most suitable LMS for implementing those new features is Moodle (Modular Object-oriented Dynamic Learning Environment), due to its modularity and extensibility as well as its vast community of users. There have been added new features in order to enrich student’s profile and adjust learning material to the learner, depending on his profile and learning progress. The teacher has the ability to organize suitable learning objects and learning paths for each student, depending on particular user profile fields, learning styles and student’s performance. This personalized and adaptive e-learning system increases student’s motivation and participation.

Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-05-09T12:29:34Z No. of bitstreams: 1 DissAESCSF.pdf: 8504536 bytes, checksum: 5aa7619eb4ee6026af071cd2ad3bd1e2 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-05-11T18:14:22Z (GMT) No. of bitstreams: 1 DissAESCSF.pdf: 8504536 bytes, checksum: 5aa7619eb4ee6026af071cd2ad3bd1e2 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-05-11T18:14:30Z (GMT) No. of bitstreams: 1 DissAESCSF.pdf: 8504536 bytes, checksum: 5aa7619eb4ee6026af071cd2ad3bd1e2 (MD5) / Made available in DSpace on 2017-05-11T18:19:28Z (GMT). No. of bitstreams: 1 DissAESCSF.pdf: 8504536 bytes, checksum: 5aa7619eb4ee6026af071cd2ad3bd1e2 (MD5) Previous issue date: 2016-08-29 / Não recebi financiamento / The main purpose of this study is to analyze, by using Discursive Sequences, the paradox established during the construction of the teacher’s image in the twenty-first century. The corpus of this research consists of two Learning Management Systems (LMS) - Schoology and Edmodo - and official documents such as Leis de Diretrizes e Bases. French Discourse Analysis will be used as theory and method, in which authors as Pêcheux (1995, 2008) and Orlandi (2004, 2009, 2014) define concepts such as paraphrasing and metaphor for construction and maintenance of discourse. These concepts, related to Dominique Julia’s theory (2000), evoke the discursive memory and its effects on the development of the teacher’s image due to technological changes. / Este estudo analisa, utilizando Sequências Discursivas (SD), o paradoxo que se apresenta na construção da imagem do docente no século XXI. O corpus dessa pesquisa é formado por dois Sistemas de Gerenciamento de Aprendizagem (SGA) – Schoology e Edmodo – e documentos oficiais, como as Leis de Diretrizes e Bases. A base teórico-metodológica é a Análise de Discurso Francesa, na qual autores como Pêcheux (1995, 2008) e Orlandi (2004, 2009, 2014) definem conceitos como paráfrase e metáfora para construção e manutenção do discurso. Esses conceitos, ao serem associados à fala do historiador Dominique Julia (2000), no âmbito histórico evocam a memória discursiva e seus efeitos produzidos na elaboração do imaginário docente diante das mudanças tecnológicas.

Submitted by Automação e Estatística (sst@bczm.ufrn.br) on 2018-04-11T20:06:38Z No. of bitstreams: 1 BrunoJacomeCavalcanti_TESE.pdf: 5397909 bytes, checksum: 5a245eec570a69adf8ca5d791aaddf70 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-04-16T20:46:19Z (GMT) No. of bitstreams: 1 BrunoJacomeCavalcanti_TESE.pdf: 5397909 bytes, checksum: 5a245eec570a69adf8ca5d791aaddf70 (MD5) / Made available in DSpace on 2018-04-16T20:46:19Z (GMT). No. of bitstreams: 1 BrunoJacomeCavalcanti_TESE.pdf: 5397909 bytes, checksum: 5a245eec570a69adf8ca5d791aaddf70 (MD5) Previous issue date: 2017-10-20 / A perfeita funcionalidade dos sistemas de comunicações de 3ª. e 4ª. gerações requerem, entre outras coisas, do conhecimento dos valores numéricos da predição das perdas de propagação dos sinais propagantes nos ambientes urbano, suburbano e rural. Portanto, o estudo das condições de propagação em um ambiente qualquer sempre será uma preocupação dos engenheiros projetistas. A análise e desenvolvimento de modelos robustos de predição de perdas de propagação em redes de comunicações Long Term Evolution (LTE) e Long Term Evolution Advanced (LTE-A) usando técnicas de Inteligência Artificial são realizadas neste trabalho. Os procedimentos metodológicos empregados foram aplicados no melhoramento da predição dos modelos de perda de propagação empíricos SUI, ECC-33, Ericsson 9999, TR 36.942 e o modelo do Espaço Livre, aplicados em redes LTE e LTE-A nas frequências de 800 MHz, 1800 MHz e 2600 MHz, para ambientes suburbanos em cidades de porte médio do nordeste do Brasil. Assim, nesta tese propõem-se dois modelos de Redes Neurais Artificiais (RNA): (i) o modelo de rede neural com entradas baseadas em erro (RNBE), utilizando como principal alimentador da rede o erro entre dados medidos e simulados, e, (ii) o modelo de rede neural com entradas baseadas no terreno (RNBT). O desempenho desses modelos foram comparados com os modelos de propagação considerados no trabalho e também as versões otimizadas utilizando Algoritmos Genéticos (AG) e o Método dos Mínimos Quadrados (LMS). Também foram realizadas comparações com valores medidos, obtidos a partir de uma campanha de medição realizada na cidade de Natal, Estado do Rio Grande do Norte. Os resultados finais obtidos através de simulações e medições apresentaram boas concordâncias métricas, com destaque para a performance do modelo RNBE. A principal contribuição dessa tese é que, ao utilizar essas técnicas que fazem uso de maneira mais eficiente dos modelos de propagação empíricos, pode-se estimar sinais propagantes realistas, evitando erros no planejamento e implementações de redes sem fio LTE e LTE-A em áreas suburbanas. / The perfect functionality of the 3rd and 4th generation of wireless systems requires, among other parameters, knowledge of the numerical values of the prediction of loss of propagation of propagation signals in urban, suburban and rural environments. Therefore, the study of propagation conditions in any environment will always be a concern of design engineers. The analysis and development of robust propagation loss prediction models in Long Term Evolution (LTE) and Long Term Evolution Advanced (LTE-A) communications networks using Artificial Intelligence techniques is performed in this work. The methodologies used were applied to improve the prediction of loss of empirical propagation SUI, ECC-33, Ericsson 9999, TR 36.942 models and the Free Space model applied in LTE and LTE-A networks in the frequencies of 800 MHz, 1800 MHz and 2600 MHz, for suburban environments in mid-sized cities in northeastern Brazil. Thus, in these thesis two models of Artificial Neural Networks (RNA) are proposed: (i) the neural network model with inputs based on error (RNBE) using as main feeder of the network the error between measured and simulated data, and (ii) the neural network model with land-based inputs (RNBT). The performance of these models was compared with the models of propagation considered in the work and also the versions optimized using Genetic Algorithms (AG) and the Least Square Method (LMS). Comparisons were also made with measured values, obtained from a measurement campaign carried out in the city of Natal, state of Rio Grande do Norte. The final results obtained through simulations and measurements presented good metric concordances, with emphasis on the performance of the RNBE model. Thus, the main contribution of this thesis is that, by using these techniques that make more efficient use of empirical propagation models, we can estimate realistic propagation signals, avoiding errors in the planning and implementations of LTE and LTE- A wireless networks in suburban areas.