Analytic models for the performance of the forward link of 3G CDMA systems using different maximum ratio combining (MRC) RAKE finger weight assignments are presented. The spreading modulations under investigation are the balanced QPSK and the complex-spreading QPSK. The models are computationally efficient, accurate, and applicable to Root Raised Cosine (RRC) pulse shaping with any roll-off factor, variable processing gain, chip rate, and data rate for orthogonal codes, random codes, quasi-orthogonal codes, Gaussian noise, and realistic channel models. The expressions derived are then used to obtain the so-called orthogonality factor, which is commonly used in system-level simulations. Next, closed-form mathematical expressions for the variance due to infinite chips interfering in systems using arbitrary Nyquist pulses are derived. These expressions are applicable to both the forward link and the reverse link. For the latter, the existing knowledge on the accurate and efficient estimation of the performance of CDMA systems is extended by presenting closed mathematical expressions for bandlimited systems using arbitrary Nyquist pulses for both BPSK and Offset-QPSK (OQPSK) modulation. The impact of adjacent channel interference in bandlimited systems is subsequently considered. Finally, mathematical expressions for the accurate and efficient estimation of a CDMA system using RRC pulse-shaping and a RAKE receiver in the presence of multipath interference are presented.

Dynamic optimal fragmentation with rate adaptation (DORA) is an algorithm to achieve maximum goodput in wireless mobile networks. With the analytical model that incorporates number of users, contentions, packet lengths, and bit error rates in the network, DORA computes a fragmentation threshold and transmits optimal sized packets with maximum rates. To estimate the SNR in the model, an adaptive on-demand UDP estimator is designed to reduce overheads. Test-beds to execute experiments for channel estimation, WLANs, Ad Hoc networks, and Vehicle-to-Vehicle networks are developed to evaluate the performance of DORA. DORA is an energy-efficient generic CSMA/CA MAC protocol for wireless mobile computing applications, and enhances system goodput in WLANs, Ad Hoc networks, and Vehicle-to-Vehicle networks without modification of the protocols.

In this work, we consider the channel assignment problem in single radio multi-channel mobile ad-hoc networks. Specifically, we investigate the granularity of channel assignment decisions that gives the best trade-off in terms of performance and complexity. We present a new granularity for channel assignment that we refer to as component level channel assignment. The strategy is relatively simple, and is characterized by several impressive practical advantages. We also show that the theoretical performance of the component based channel assignment strategy does not lag significantly behind the optimal possible performance, and perhaps more importantly we show that when coupled with its several practical advantages, it significantly outperforms other strategies under most network conditions.

In this dissertation, not only the antenna and antenna array design techniques for fourth-generation mobile communication system are proposed, but also the specifications related to antenna bio-compatibility are studied. At first, two dual-wideband design techniques suitable to be applied for laptop computer applications for LTE/WWAN and LTE MIMO operations are proposed. The techniques can also be applied to internal tablet computer antennas. The isolation issues of MIMO antenna array of different mobile communication devices, such as laptop computer, tablet computer, and mobile phone, are then discussed. Finally, an analysis of body SAR for tablet computer applications are given and discussed.

By employing a low-cost loop antenna of simple structure, a novel antenna design to efficiently make use of the system ground plane of a PDA (personal digital assistant) is proposed. Owing to a small distance of 3 mm between the antenna and the ground plane, the propose antenna has a very low profile. By selecting a proper loop¡¦s length-to-width ratio, two resonant modes close to each other can be excited, which lead to an impedance bandwidth of 17%. In addition, because of the same direction of the surface currents on the radiating metal plate, the antenna peak gain reaches about 4.5 dBi, which is attractive for application in PDAs.

In this thesis the study mainly focuses on the trends in development of present-day mobile phones and provides a promising alternative for integrating various elements inside mobile phones. With the presence of a small ground plane protruded from the main circuit board of a mobile phone, the proposed antenna design is substantially different from the configuration of feeding the conventional internal patch or planar inverted-F antenna (PIFA), and the proposed antenna can be placed in close proximity to the RF shielding case in the mobile phone, with very small effects on the antenna performances. Thus, more flexibility in the integration between an internal antenna and other associated elements inside a mobile phone can be obtained. In addition, by making use of the space inside the shorting cylinder of the internal PIFA, which can be treated as a shielding wall, the lens module of an embedded digital camera or other possible practical modules can easily fit in the cylinder to satisfy the trends in development of the miniaturized and multi-function mobile phones.

In this dissertation, EMC antennas for mobile communication device applications are proposed. This kind of EMC antennas can overcome the problem that happens to the conventional antenna; in practical application, when electronic components are placed very close to the conventional antenna, large degradation of the antenna performance will occur. In the proposed EMC antennas, by adding a vertical antenna ground plane functioning as a shielding metal wall, EM coupling between the EMC antenna and nearby components can be reduced. Thus, it leads to no degradation or only negligible variations of the antenna performance. Also, the concept of EMC antennas can be applied to the monopole antenna. One of the examples suitable for the future thin (< 10 mm) mobile communication device is demonstrated. Further, the user¡¦s hand effects on EMC antenna performance are analyzed. Even when the mobile phone is hand-held at the bottom, large radiation efficiency drops are observed, especially for the GSM band.

The purpose of this research is to study the acceptance of road-users on the real-time integrated digital traffic information system, with the use of Technology Acceptance Model (TAM) and Media Richness Theory (MRT) as foundations. Further understanding on the properties and demands of populations in the use of real-time integrated digital traffic information system are done through the application of ANOVA (Analysis of Variance) and Regression Analysis. Moreover, with the integration of real time police road condition broadcasting and mobile communication technology, an ideal real-time integrated digital traffic information system is built¡Xthe Mobile Messenger, and a mobile communication technology is developed as main point of service infrastructure. Transforming static broadcasting service into mobile information service, road-users are provided with a high-speed, safe and quality driving environment.

The mobile communication market in Taiwan is blooming developing, and the number of mobilephone users is growing up. Nowadays, over 90% of having-a-mobilephone users in Taiwan, even this number are tending toward saturation at present. Therefore, the telecommunication providers expect mobile value-added service can increase the revenue by taking advantage of 3G high-speed transfer rate. But lacking of the ¡§Killer App¡¨, this service doesn¡¦t attract people to use. The ARPU (average revenue per user) doesn¡¦t improve much as we anticipated. The purposes of this study are to realize present situation of mobile value-added service¡¦s development and to develop acceptable content that can be implemented. The study collected literatures and documents to analyze progress of mobile communication system¡¦s development and present situation of mobile value-added service¡¦s development, furthermore, make the development strategy of mobile value-added service according to the new product development procedure, then test user acceptance by TAM. The study proposes ¡§User-generated Content¡¨ as the new mobile value-added service. This service has 6 characters: ¡§highly personalized¡¨, ¡§timely¡¨, ¡§ease of use¡¨, ¡§rich information¡¨, ¡§highly integrated¡¨, ¡§cross platform¡¨. The result of TAM questionnaire proves that ¡§perceived usefulness¡¨ is positive influenced by ¡§timely¡¨, ¡§mobility¡¨, ¡§personalization¡¨, ¡§perceived ease of use¡¨, and ¡§attitude toward using¡¨ is positive influenced by ¡§perceived usefulness¡¨, ¡§perceived ease of use¡¨, ¡§relatives and friends¡¦ influence¡¨, ¡§price¡¨.

Thesis (MS)--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Jian Tang. Includes bibliographical references (leaves 53-54).