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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

中國大陸山寨手機產業發展 / Development of shanzhaiji handset industry in Mainland China

黃明德, Huang, Frankie Ming-Te Unknown Date (has links)
The emergence of shanzhaiji handset industry or bandit handset industry (山寨機手機產業) is an interesting phenomenon that is the only socioeconomic behavior occurring in mainland china. According to the National Development and Reform Commission of PRC, a company is permitted to produce the cellular phones with 200 million RMB and R&D capabilities. However, with only 100 thousands RMB capital, a shanzhaji handset producer can deliver the cellular phones in mainland china by getting a core technology of one package of chipset total solution (turnkey) from MediaTek / MTK (聯發科) in Taiwan. This new business model has been impacting the phone industry significantly in the mainland china. My research will focus on the development of entire shanzhaiji industry development from its origin to the status quo as well as future development. Three aspects of supply chain, market channel and government policy in terms of shanzhaiji industry are addressed in this research.
2

Identification of cellular handsets through radio frequency signature extraction on an FPGA platform / Johannes Petrus Hattingh

Hattingh, Johannes Petrus January 2015 (has links)
Specific emitter identification refers to the process of performing identification of radio frequency transmitters by exploiting unique variations in emitted signals, caused by hardware variations. In previous research, specific emitter identification was successfully performed on GSM handsets. However, no research has been done on the implementation of specific emitter identification of GSM handsets on an FPGA platform. This study focuses on feature extraction and identification algorithms, as well as the implementation of the identification algorithm on an FPGA. During this study, phase modulation error was used, as previous research indicated that phase modulation error is an effective feature set for identification purposes. As the implementation of a classification algorithm on an FPGA was required, a trade-off between complexity and feasibility needed to be made during the selection process. The artificial neural network was selected as the optimal classifier for implementation on an FPGA. The algorithm was first implemented in software and used as the basis for the design on an FPGA. A piece-wise linear approximation of a sigmoid function was used to approximate the activation function, where a look-up table was used to store the parameters. The off-line training of the artificial neural network was performed in software using the back-propagation gradient descent algorithm. Good results for the identification of GSM handsets on an FPGA were obtained, with a true acceptance ratio of 97.0%. This result is similar to the performance obtained in previous research performed in software. In this study, it was found that specific emitter identification of GSM handsets can be performed on an FPGA. Real-world applications for this technology include general cellular handset identification and access control. / MSc (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2015
3

Identification of cellular handsets through radio frequency signature extraction on an FPGA platform / Johannes Petrus Hattingh

Hattingh, Johannes Petrus January 2015 (has links)
Specific emitter identification refers to the process of performing identification of radio frequency transmitters by exploiting unique variations in emitted signals, caused by hardware variations. In previous research, specific emitter identification was successfully performed on GSM handsets. However, no research has been done on the implementation of specific emitter identification of GSM handsets on an FPGA platform. This study focuses on feature extraction and identification algorithms, as well as the implementation of the identification algorithm on an FPGA. During this study, phase modulation error was used, as previous research indicated that phase modulation error is an effective feature set for identification purposes. As the implementation of a classification algorithm on an FPGA was required, a trade-off between complexity and feasibility needed to be made during the selection process. The artificial neural network was selected as the optimal classifier for implementation on an FPGA. The algorithm was first implemented in software and used as the basis for the design on an FPGA. A piece-wise linear approximation of a sigmoid function was used to approximate the activation function, where a look-up table was used to store the parameters. The off-line training of the artificial neural network was performed in software using the back-propagation gradient descent algorithm. Good results for the identification of GSM handsets on an FPGA were obtained, with a true acceptance ratio of 97.0%. This result is similar to the performance obtained in previous research performed in software. In this study, it was found that specific emitter identification of GSM handsets can be performed on an FPGA. Real-world applications for this technology include general cellular handset identification and access control. / MSc (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2015
4

What is wrong with Motorola?

Chen, Qian, Chen, Lanjunzi January 2008 (has links)
<p>Date: 2008‐05‐26</p><p>Program: International Marketing Course: Master Thesis</p><p>Authors: Qian Chen & Lanjunzi Chen</p><p>Title: What is wrong with Motorola?</p><p>Problem: What are the shortcomings of its mobile phones of Motorola from</p><p>consumers’ perspectives in Chinese market?</p><p>Purpose: This study aims to find out different factors of Motorola’s mobile phone</p><p>which may hamper consumers’ interest and possibility of purchasing when Motorola</p><p>experience the declining sales of mobile phone in Chinese market.</p><p>Method: The researchers apply marketing mix to investigate the shortcoming of</p><p>Motorola’s handset to achieve the research purpose. The researchers choose</p><p>questionnaires and interviews to collect information from consumers in order to</p><p>gather information for this research.</p><p>Target Group: This paper might be useful for Motorola Company to find their</p><p>problems and some companies also produce cellphone avoid coming out similar</p><p>problems.</p><p>Conclusions: Based on our research Motorola’s handsets certainly have many</p><p>shortcomings in marketing mix that is product, price, place and promotion from</p><p>consumers’ point view</p><p>Recommendations: There are a lot of aspects for Motorola to improve from product,</p><p>price, place and promotion in the long run in order to recover its reputation in</p><p>consumers’ mind.</p><p>Key Words: Motorola handset, consumers’ point of view, shortcomings, China,</p><p>product, price, place, promotion</p>
5

What is wrong with Motorola?

Chen, Qian, Chen, Lanjunzi January 2008 (has links)
Date: 2008‐05‐26 Program: International Marketing Course: Master Thesis Authors: Qian Chen &amp; Lanjunzi Chen Title: What is wrong with Motorola? Problem: What are the shortcomings of its mobile phones of Motorola from consumers’ perspectives in Chinese market? Purpose: This study aims to find out different factors of Motorola’s mobile phone which may hamper consumers’ interest and possibility of purchasing when Motorola experience the declining sales of mobile phone in Chinese market. Method: The researchers apply marketing mix to investigate the shortcoming of Motorola’s handset to achieve the research purpose. The researchers choose questionnaires and interviews to collect information from consumers in order to gather information for this research. Target Group: This paper might be useful for Motorola Company to find their problems and some companies also produce cellphone avoid coming out similar problems. Conclusions: Based on our research Motorola’s handsets certainly have many shortcomings in marketing mix that is product, price, place and promotion from consumers’ point view Recommendations: There are a lot of aspects for Motorola to improve from product, price, place and promotion in the long run in order to recover its reputation in consumers’ mind. Key Words: Motorola handset, consumers’ point of view, shortcomings, China, product, price, place, promotion
6

Configuration and Implementation Issues for a Firewall System Running on a Mobile Handset

Martinsen, Pal-Erik January 2005 (has links)
Any device connected to the Internet needs to be protected. Using a firewall as a first line of defence is a very common way to provide protection. A firewall can be set up to protect an entire network or just a single host. As it is becoming more and more popular to connect mobile phones and other hand held devices to the Internet, the big question is;"how to protect those devices from the perils of the Internet?" This work investigates issues with the implementation of a firewall system for protecting mobile devices. Firewall administration is an error prone and difficult task. Setting up a correctly configured firewall in a network setting is a difficult task for a network administrator. To enable an ordinary mobile phone user to set up a firewall configuration to protect his mobile phone it is important to have a system that is easy to understand and warns the user of possible mistakes. Generic algorithms for firewall rule-set sorting and anomaly discovery are presented. This ensures that the rule-set is error free and safe to use. This is a vital part of any firewall system. The prototype developed can be used to find errors in existing firewall rule-sets. The rule-set can be in either a native firewall configuration format (currently only IPF is supported) or in a generic XML format. This generic XML format was developed as a part of this research project. Further a new graphical visualization concept that allows the end user to configure an advanced firewall configuration from a device with a small screen and limited input possibilities is presented.
7

A Capacitively loaded Antenna for use in Mobile Handsets

Elfergani, Issa T., Abd-Alhameed, Raed, See, Chan H., Child, Mark B., Excell, Peter S. 08 November 2010 (has links)
Yes / A tuneable slotted patch antenna design is presented and verified for use in the DCS, PCS and UMTS bands. The tuning circuit consists of two varactor diodes with some passive components, and is integrated fully with the r radiator patch, with the varactors occupying different locations over the slot. The tuning does not require any further modification to the patch or feed geometry. Good agreement is observed between the predicted and observed impedance bandwidth, return loss, gain and radiation pattern, throughout the range 1.70 GHz-2.05 GHz.
8

A planar dual-polarized phased array with broad bandwidth and quasi end-fire radiation for 5G mobile handsets

Ojaroudi Parchin, Naser, Zhang, J., Abd-Alhameed, Raed, Pedersen, G.F., Zhang, S. 11 April 2021 (has links)
Yes / A planar dual-polarized phased array is proposed for 5G cellular communications. The array has the properties of dual-polarization, wideband and quasi end-fire radiation, which is printed on one side of a single-layer substrate. The design contains two 8-element sub-arrays including horizontally polarized end-fire dipole antennas and vertically polarized end-fire periodic slot antennas, employed on the PCB ground plane of the 5G mobile platform. Both sub-arrays provide wide bandwidth to cover 28 and 38 GHz (promising 5G candidate bands). The -10 dB impedance bandwidth of the proposed CPW-fed dipole and slot antennas are 26.5-39.5 GHz and 27.1-45.5 GHz, respectively. Moreover, for -6 dB impedance bandwidth, these values could be more than 20 GHz (24.4-46.4 GHz for the dipole antenna) and 70 GHz (22.3-95 GHz for the slot antenna). The fundamental characteristics of the proposed dual-polarized 5G antenna array in terms of the impedance bandwidth, realized gain, polarization, radiation pattern, and beam steering are investigated and good results are obtained. The clearance of the proposed dual-polarized 5G antenna array is less than 4.5 mm which is sufficient for cellular applications. / This work is partially supported by the InnovationsFonden project of Reconfigurable Arrays for Next Generation Efficiency (RANGE), AAU Young Talent Program, and European Union’s Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-ITN-2016SECRET-722424.
9

Ultra-Compact mm-Wave Monolithic IC Doherty Power Amplifier for Mobile Handsets

Sajedin, M., Elfergani, Issa T., Rodriguez, Jonathan, Abd-Alhameed, Raed, Fernandez-Barciela, M., Violas, M. 07 September 2021 (has links)
Yes / This work develops a novel dynamic load modulation Power Amplifier (PA) circuity that can provide an optimum compromise between linearity and efficiency while covering multiple cellular frequency bands. Exploiting monolithic microwave integrated circuits (MMIC) technology, a fully integrated 1W Doherty PA architecture is proposed based on 0.1 µm AlGaAs/InGaAs Depletion- Mode (D-Mode) technology provided by the WIN Semiconductors foundry. The proposed wideband DPA incorporates the harmonic tuning Class-J mode of operation, which aims to engineer the voltage waveform via second harmonic capacitive load termination. Moreover, the applied post-matching technique not only reduces the impedance transformation ratio of the conventional DPA, but also restores its proper load modulation. The simulation results indicate that the monolithic drive load modulation PA at 4 V operation voltage delivers 44% PAE at the maximum output power of 30 dBm at the 1 dB compression point, and 34% power-added efficiency (PAE) at 6 dB power back-off (PBO). A power gain flatness of around 14 ± 0.5 dB was achieved over the frequency band of 23 GHz to 27 GHz. The compact MMIC load modulation technique developed for the 5G mobile handset occupies the die area of 3.2. / This research was funded by the European Regional Development Fund (FEDER), through COMPETE 2020, POR ALGARVE 2020, Fundação para a Ciência e a Tecnologia (FCT) under i-Five Project (POCI-01-0145-FEDER-030500). This work is also part of the POSITION-II project funded by the ECSEL joint Undertaking under grant number Ecsel-345 7831132-Postitio-II-2017-IA. This work is supported by FCT/MCTES through national funds and when applicable co-funded EU funds under the project UIDB/50008/2020-UIDP/50008/2020. The authors would like to thank the WIN Semiconductors foundry for providing the MMIC GaAs pHEMT PDKs and technical support. This work is supported by the Project TEC2017-88242-C3-2-R- Spanish Ministerio de Ciencia, Innovación e Universidades and EU-FEDER funding.
10

Novel Designs for Broadband Slot Mobile Phone Antenna

Lin, Po-wei 22 June 2011 (has links)
In this thesis, two novel broadband slot mobile phone antenna designs respectively for penta-band WWAN operation and eight-band LTE/WWAN operation are presented. The antennas are suitable to be mounted near the bottom edge of the system ground plane of the mobile phone. Good radiation characteristics for the antennas are obtained, and the two antennas respectively occupy a small printed area of 50 ¡Ñ 4 mm2 and 53 ¡Ñ 4 mm2. The first design uses a C-shaped strip connected to the bottom edge of the system ground plane to make the structure of the system ground plane close to a symmetric shorted dipole antenna. This makes it promising to excite a chassis mode to enhance the operating bandwidth of the antenna. The second one uses a microstrip feedline having a chip-inductor-loaded branch. The novel microstrip feedline can lead to more uniform distribution of the electric fields excited in the slot such that enhanced bandwidth of the antenna¡¦s lower band is obtained. Further, since the chip inductor performs like a low-pass filter, the original bandwidth of the antenna¡¦s upper band is not affected. Additionaly, the impedance matching of the lower frequencies of the upper band can be improved, which enhances the upper-band bandwidth of the antenna. Effects of the user¡¦s head and hand on the proposed antenna are also studied, and the simulated SAR and HAC issues are also analyzed in this thesis.

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