Power-amplifier efficiency is a significant issue for the overall efficiency of most wireless system. Therefore, currently there are different kind of Switched mode power amplifiers are developed which are showing very high efficiency also at higher frequencies but all of these amplifiers are subjected to drive with the constant envelope signals. Whereas, for the increasing demand of high data rate transmissions in wireless communication there are some new modulation schemes are introduced and which are generating no more a constant envelope signal but a high peak to average power signal. Therefore, recently a new technique is proposed called the burst mode operation for operating the switched mode power amplifiers efficiently while driven by a high peak to average power signal.   The purpose of this master thesis work was to review the theory of this burst mode operation and some basic investigations of this theory on switched mode power amplifiers were performed in simulation environments. The amplifiers of class D, inverse D, DE and J are studied. The thesis work was mainly carried out by ADS and partly in MATLAB SIMULINK environment. Since this burst mode operation is a completely new technique therefore a new Harmonic balance simulation setups in ADS and Microwave Office are developed to generate the RF burst signals.   A Class J amplifier based on LDMOS technique is measured by a 16 carrier multi-tone signal having peak to average power ratio of 7 dB and achieved the drain efficiency of 50% with -30 dBc linearity at 946 MHz.

The increasing use of data services and the importance of IP basedservices in third generation mobile communication system (3G), requires the transmission from the cell phone to the base station, i.e. uplink, to manage high speed data rates. In the air interface for 3G in Europe, WCDMA, a concept for enhancing the transmission from the cell phone to the base station, called Enhanced Uplink, is being standardized. The overall goal is to provide high speed data access for the uplink. One of the requirements is that the enhanced uplink channels must be able to coexist with already existing WCDMA releases. For example, the enhanced uplink must not impact seriously on real time services, such as speech, carried on current WCDMA channels. The purpose of this work is to study how the quality, coverage and capacity of real time services carried on previous WCDMA releases is affected when introducing the Enhanced Uplink in a WCDMA network. The main focus of the study is thus to demonstrate the trade-off between voice and best effort performances. Theoretical assessments and simulations show that the Enhanced Uplink has many advantages over previous WCDMA releases. For example the Enhanced Uplink yields a larger system throughput for all voice loads. The noise rise, i.e. the ratio of total received power to the background noise power is being considered as the resource. It is shown that user traffic carried on the Enhanced Uplink is able to operate under a higher noise rise level as well as to get a higher throughput per noise rise. The resource is hence more efficiently utilized.

In our technological society, the growth of applications is not always followed by the growth of network capacity. There is an increasing demand of bandwidth which cannot always be answered properly. It is especially true in wireless networks such as 3G. Mobile devices can store and use more and more applications which are all using the bandwidth without any control. The Internet experience for the end user can thus be quickly degraded. In this respect, my objective in this thesis is to fill the gap on this matter by implementing a traffic shaping software working on Android devices. In order to get the necessary knowledge to create such an application, series of tests are conducted on similar software based on Windows 7. The outcome of this research is my own solution to shape the traffic on Android mobile devices. The software allows the end user to choose which of his applications should get a higher priority to improve his overall experience with them.

This thesis studies the Message Queue Telemetry Transport protocol (MQTT) as an application layer protocol in geographical location sharing applications using third generation cellular communication (3G). The MQTT protocol is compared in terms of energy efficiency and amount of data generated with the Hypertext Transfer Protocol (HTTP), which is currently used in typical location sharing applications. In order to compare the communication energy efficiency of both protocols a location sharing application prototype was developed for the Android platform. The application allows the use of HTTP and MQTT and was used to perform a number of experiments. The evaluation experiments show that MQTT is a good candidate as a protocol for location sharing. At comparable bandwidth and energy expenses MQTT offers better quality of user experience, since the subscribers are notified at once when the location of clients of interest has changed. The MQTT protocol is more energy-efficient than the HTTP protocol when the number of other uses with whom the client shares location is low and the location updates are frequent. The experiments also indicate that MQTT protocol is more energy-efficient than HTTP protocol in idle state, when there are no location information updates due to inactivity of all the clients, for example, if they are stationary. This is because MQTT client does not spend energy to poll the server for information updates.

The interest for various multimedia services accessed via the Internet has been growing immensely along with the bandwidth available. A similar development has emerged in the 3G mobile network. The focus of this master thesis is on the speech/audio part of a 3G multimedia application. The purpose has been to implement a traffic generating tool that can measure QoS (Quality of Service) in 3G networks. The application is compliant to the 3G standards, i.e. it uses AMR (Adaptive Multi Rate), SIP (Session Initiation Protocol) and RTP (Real Time Transport Protocol). AMR is a speech compression algorithm with the special feature that it can compress speech into several different bitrates. SIP signalling is used so that different applications can agree on how to communicate. RTP carries the speech frames over the network, in order to provide features that are necessary for media/multimedia applications. Issues like perception of audio and QoS related parameters is also discussed, from the perspective of users and developers.

The Internet has mainly been interconnecting stationary computers by wired links, but an increasing number of mobile clients require wireless communication. One way to connect these clients is to use the Universal Mobile Telecommunication System, UMTS. UMTS is a third generation mobile system. A network can be seen as nodes interconnected by links. The functionality of the nodes can be described as a layered hierarchy. A reference model for this hierarchy was developed by OSI. In this model the second lowest layer is called data link layer. The data link layer is responsible for making the raw transmission appear error free to upper layers. The focus for this thesis is the data link layer in the UMTS. Compared to the data link layer in a wired scenario it contains more control and error correction mechanisms. These mechanisms use a lot of timers and triggers, which makes it very difficult to analyze them mathematically. Therefore simulation is the preferred method. For the simulations the network simulator version 2 was used. This is an open source discrete event simulator. It has a modularized wireless stack already implemented. This can not be used to simulate UMTS though. Some modules in this stack were replaced by a new implementation to make simulations on UMTS possible. Tests were performed on the new implementation and the results were what could be expected. The results were also consistent with previous research in the area.

In this thesis, a novel Scalable Multiple Description Coding (SMDC) framework is proposed. To address the bandwidth fluctuation, packet loss and heterogeneity problems in the wireless networks and further enhance the error resilience tools in Moving Pictures Experts Group 4 (MPEG-4), the joint design of layered coding (LC) and multiple description coding (MDC) is explored. It leverages a proposed distributed multimedia delivery mobile network (D-MDMN) to provide path diversity to combat streaming video outage due to handoff in Universal Mobile Telecommunications System (UMTS). The corresponding intra-RAN (Radio Access Network) handoff and inter-RAN handoff procedures in D-MDMN are studied in details, which employ the principle of video stream re-establishing to replace the principle of data forwarding in UMTS. Furthermore, a new IP (Internet Protocol) Differentiated Services (DiffServ) video marking algorithm is proposed to support the unequal error protection (UEP) of LC components of SMDC. Performance evaluation is carried through simulation using OPNET Modeler 9. 0. Simulation results show that the proposed handoff procedures in D-MDMN have better performance in terms of handoff latency, end-to-end delay and handoff scalability than that in UMTS. Performance evaluation of our proposed IP DiffServ video marking algorithm is also undertaken, which shows that it is more suitable for video streaming in IP mobile networks compared with the previously proposed DiffServ video marking algorithm (DVMA).

This thesis proposes a variety of antenna designs suitable for modern of mobile products, such as mobile phones, PDAs and so forth, on both the 2G and 3G communication systems according to the mobile communication development. Based on the integration of monopole or planar inverted-F antenna with the system ground planes, multi-frequency, broadband, and high radiation efficiency can be achieved, which is very promising to be adapted into communication products. Furthermore, an antenna capable of WLAN and UWB is proposed for future wireless communication applications.

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.

The applications of mobile phone provide limitless convenience to people¡¦s life. 3G mobile phone provides a great contribution to communications due to wide range bandwidth. 3G mobile phone is able to economize on communicating time and space. Therefore, it plays an important role in the currently mobile market. In addition the governments have devoted much resource on 3G mobile learning as the hardware and software. The study aims to examine the female consumers of 3G mobile phone and consider the market of mobile phone industry, mobile phone technology and further development of mobile phone. Related literatures are sourced from the develop background of the current mobile market, demand of the mobile phone market and consumer characteristics in order to filter out the priority setting of those six categories as follows: network connection, hardware design, safe internet, business model and the mobile service of convenient and appreciations. Beside this, it also presents that the priority setting might change as a matter of time. Research method is Analytic Hierarchy Process (AHP). In the project, questionnaire results provide the bulk of the data, with the interviews intended to provide a more contextual element to the work. The questionnaire was developed and sent out to female consumers of 3G mobile phone; and the interviews were carried out with some professors of 3G mobile leaning. The results of this study suggested that the main female consumers of 3G mobile phone are young ladies who have higher education and these consumers need to receive a lot of information to help them handle works. In addition it can help them to develop the commutations. In other words, 3G mobile phone can bring more convenient in life and work. Meanwhile, the key point to promote the 3G mobile phone is the service of applications; especially the service refers to the characteristics of 3G mobile phone. For female consumers, service design should focus on female characteristics of life and special demands. For example, the service of fixing and tracking design is better for married women who have children; the service of providing life information is suit for young business ladies. After developing the service of applications, users will be used to 3G mobile phone. Then, it could be successful to expand the 3G mobile phone market of the female consumers.