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Ryken, Marv. "C-Band TM Smart Antenna." International Foundation for Telemetering, 2012. http://hdl.handle.net/10150/581445.
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ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, CaliforniaThis paper addresses the system requirements of the C-Band TM antenna that will take the place of the S-Band TM antenna used in applications on munitions and targets that require a quasi-omni directional antenna pattern. For these applications, the C-Band TM effective radiated power (ERP) must be approximately 3 dB higher than the S-Band TM ERP to achieve the same system performance due mainly to weather and environmental differences. From a systems stand-point, this will be a problem for the following reasons: power amplification at higher frequencies is usually less efficient, there is a limit on prime power due to battery capabilities, and a more complex corporate feed at C-Band as compared to S-Band will produce more loss. This means that a more fruitful approach would be to use smart antenna ideas to achieve the required higher ERP as compared to current approaches of using higher power transistors and more battery power. Several smart antenna ideas are introduced in this paper, switchable driven element antenna is described including active amplification at each element.
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Hwang, Seung-Hyeon. "Adaptive antenna techniques for smart antennas and radar systems." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2005. http://wwwlib.umi.com/cr/syr/main.
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Reis, Helder Vasconcelos Graça. "Smart antenna for RFID applications." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14541.
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Mestrado em Engenharia Electrónica e TelecomunicaçõesThe adoption and proliferation of information systems in many business and personal activities leads to the need of tagging and tracking items and services. Radio frequency identi cation (RFID) systems were developed as an e ort to answer the increasing needs of particulars and enterprises alike for wireless identi cation of objects and data exchange services, enabling a large number of businesses to reduce costs and increase revenue. As to further develop the e ciency provided by businesses worldwide, smart antenna systems were introduced as core component in their production and service providing lines, opening the path for innovative and robust wireless RFID based communication schemes, providing advanced signal capturing, processing characteristics and enhanced tracking and process automation. Smart antennas can be installed within RFID readers, enabling them to more e ciently process returned echoes by the tags and therefore improving the identi cation mechanism. RFID reader architectures with an embedded smart antenna network reliably improve the throughput, the reading speed and position detection of tagged items. A smart antenna based circuit is proposed here for RFID assisted localization and for beam steering applications using a uniform linear array of microstrip directional antennas. Several beamforming and direction of arrival estimation methods were employed in order to analyze their performance and resolution based on the computational load, modulation, and the overall environment in which the smart anetnna system may be deployed.
A adoção e proliferação de sistemas de informação em várias indústrias e atividades pessoais são responsáveis pela crescente necessidade de identifcar e rastrear itens e serviços. Sistemas de identificação por rádiofrequência (RFID) foram desenvolvidos de modo a responder às crescentes necessidades tanto de particulares como de empresas quanto à utilização de sistemas de identificaçao e de transmissão de dados sem _os, permitindo a redução de despesas e o aumento de receitas a várias empresas. De modo a melhorar a eficiência de empresas a uma escala global, sistemas de antenas inteligentes foram introduzidos nas suas linhas de manufatura e de prestação de serviços como um componente central, abrirando o caminho para esquemas de comunicação sem _os inovadores e robustos, baseados em RFID, facultando processos de captura e processamento de sinal avançados capazes de fornecer melhorias em aplicações de rastreamento e automação de processos. Antenas inteligentes podem ser instaladas em leitores RFID, permitindo um melhor processamento de sinais transmitidos pelas etiquetas, dando origem a um método de identificação mais eficiente. A arquitectura de leitores RFID com uma rede de antenas inteligentes embutida garante melhorias na taxa de transferência e na rapidez de leitura de informação assim como na deteção de itens etiquetados. Um circuito baseado em sistemas de antenas inteligentes é proposto neste trabalho para localização assistida dispositivos RFID e para direccionamento de feixe através da utilizaçao de um agregado linear e uniforme de antenas microstrip diretivas. Várias técnicas de direcionamento de feixe e de estimativa de angulo de chegada foram utilizados, de modo a analisar o desempenho e a resolução de cada algoritmo de acordo com a carga computacional, modulação utilizada e o ambiente em que o sistema de antenas inteligentes poderá ser implementado.
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Zarei, Hossein. "RF variable phase shifters for multiple smart antenna transceivers /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/5964.
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Tidd, William Graves. "Sequential beamspace smart antenna system." Thesis, Montana State University, 2011. http://etd.lib.montana.edu/etd/2011/tidd/TiddW0511.pdf.
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This thesis proposes a design of a novel and innovative sequential beamspace (SBS) smart antenna system. The system is capable of accurate direction of arrival (DOA) estimation in beamspace and efficient beamforming. Moreover, the robust functionality of such a system includes high resolution radio frequency (RF) emitter DOA estimation and beamforming in a noisy environment in the presence of strong interference. Simulations for DOA estimation using beamspace MUSIC and beamspace Capon methods are presented in conjunction with Capon beamforming. These methods are compared and contrasted with proven element space DOA estimation techniques to demonstrate the validity and advantages of pursuing a SBS smart antenna for real-world applications. The beamspace DOA estimation accuracy, resolution, beamforming pattern, and output signal quality have been thoroughly studied and quantified. The algorithms have been tailored to utilize an 8 element uniform circular array (UCA) and an 8 channel analog beamformer (BF) operating at 5.8 GHz to gather lab-based experimental results. The simulations and experimental results show that the proposed system can achieve good performance once it is properly synchronized using a time delay correction filter. In addition, a significant decrease in hardware is realized when operating in beamspace versus element space.
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Palantei, Elyas. "Switched Parasitic Smart Antenna: Design and Implementation for Wireless Communication Systems." Thesis, Griffith University, 2012. http://hdl.handle.net/10072/366219.
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Smart antenna technology in applications such as the next-G wireless communication networks may improve the quality of service (QoS). One category of smart antennas is the switched beam smart antenna (SBA). These antennas can be grouped into plug and play antennas and adaptive internal antennas. Four types of switched beam smart antennas were investigated including a six monopole array on circular ground plane with conducting sleeve, five monopoles on a circular ground plane without a conducting sleeve, a reconfigurable monopole on a cylindrical hollow ground structure, and a reconfigurable adaptive internal antenna. The first two antennas were constructed with a switched parasitic array of elements combined with an RF circuit with microcontroller. Two of the four antenna prototypes were capable for steering the beam pattern automatically based on signal strength (RSSI) or bit error rate (BER) scanning. The two remaining antennas were designed for electronic beamforming and electronic frequency tuning. Both numerical and empirical investigations were undertaken to measure performance and investigate manufacture difficulties. The numerical investigations were undertaken using both the method of moment (MoM)-NEC and the finite element method (FEM)-HFSS modeling. The fabrication and testing in an anechoic chamber were used to explore the actual performance of the designed antennas. The fabrication of the last two types of antennas was not implemented. Further work is required to find the optimal design for all antennas investigated. This study suggests significant promise for these antennas in wireless networks.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering
Science, Environment, Engineering and Technology
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Tung, Edwin Tai-Wing. "A multiport antenna for an indoor PCS smart antenna system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ38646.pdf.
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Pal, Jitendra. "RF MEMS Switches for Smart Antenna." Thesis, Griffith University, 2016. http://hdl.handle.net/10072/368172.
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The adoption of smart antenna techniques in future wireless systems is expected to have a significant impact on the efficient use of the spectrum and the minimisation of the cost of establishing new wireless networks. RF MEMS devices are the potential candidates to revolutionise RF and microwave system implementation for next generation wireless applications. Despite having excellent performances, there are some drawbacks associated with RF MEMS switches. The main challenges with RF MEMS switches are their high actuation voltage, limited reliability and low power handling capability. This thesis presents novel RF MEMS switches which can overcome these issues. To achieve zero power consumption, we have fabricated latching RF MEMS switches. In addition, we have combined thermal actuation and electrostatic actuation mechanisms to achieve lower actuation voltage. We have also developed a novel contactless RF MEMS switch to increase the reliability of the switch. The switch is free from unavoidable stiction and micro-welding problems in other contact types, which in return guarantees high reliability and long lifetime. The proposed device is based on variable capacitance between signal lines and movable grounded electrodes controlled by electrostatic actuator. The movable grounded electrode has the capability to move bi- directionally, therefore the switch can change among ON, OFF and deep-OFF states. Thus, additional isolation can be achieved in the deep-OFF state. The switch shows excellent RF performances. To increase the power handling capability of switch, we have developed a multi-contact Single Pole Single Throw (SPST). The switch achieves uniform current distribution through each contact, thereby increasing power handling capability. The switch is actuated with separate electrodes to control the current density and direction.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering
Science, Environment, Engineering and Technology
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Elfarawi, Shaaban M. "Indoor CDMA capacity using smart antenna base station." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0019/MQ54885.pdf.
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Karnaushenko, Dmitriy D. "Compact Helical Antenna for Smart Implant Applications." Doctoral thesis, Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-230942.
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Medical devices have made a big step forward in the past decades. One of the most noticeable medical events of the twenties century was the development of long-lasting, wireless electronic implants such as identification tags, pacemakers and neuronal stimulators. These devices were only made possible after the development of small scale radio frequency electronics. Small radio electronic circuits provided a way to operate in both transmission and reception mode allowing an implant to communicate with an external world from inside a living organism. Bidirectional communication is a vital feature that has been increasingly implemented in similar systems to continuously record biological parameters, to remotely configure the implant, or to wirelessly stimulate internal organs. Further miniaturisation of implantable devices to make the operation of the device more comfortable for the patient requires rethinking of the whole radio system concept making it both power efficient and of high performance. Nowadays, high data throughput, large bandwidth, and long term operation requires new radio systems to operate at UHF (ultra-high frequency) bands as this is the most suitable for implantable applications. For instance, the MICS (Medical Implant Communication System) band was introduced for the communication with implantable devices. However, this band could only enable communication at low data rates. This was acceptable for the transmission of telemetry data such as heart beat rate, respiratory and temperature with sub Mbps rates. Novel developments such as neuronal and prosthetic implants require significantly higher data rates more than 10 Mbps that can be achieved with large bandwidth communicating systems operating at higher frequencies in a GHz range. Higher operating frequency would also resolve a strong issue of MICS devices, namely the scale of implants defined by dimensions of antennas used at this band. Operation at 2.4 GHz ISM band was recognized to be the most adequate as it has a moderate absorption in the human body providing a compromise between an antenna/implant scale and a total power efficiency of the communicating system.
This thesis addresses a key challenge of implantable radio communicating systems namely an efficient and small scale antenna design which allows a high yield fabrication in a microelectronic fashion. It was demonstrated that a helical antenna design allows the designer to precisely tune the operating frequency, input impedance, and bandwidth by changing the geometry of a self-assembled 3D structure defined by an initial 2D planar layout. Novel stimuli responsive materials were synthesized, and the rolled-up technology was explored for fabrication of 5.5-mm-long helical antenna arrays operating in ISM bands at 5.8 and 2.4 GHz. Characterization and various applications of the fabricated antennas are successfully demonstrated in the thesis.
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Yu, Xiaoming. "Multibeam smart antenna systems for wireless communications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0034/NQ66298.pdf.
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Venugopal, Arvind. "Analysis and Design of Microstrip antenna for a Smart-antenna test-bed." NCSU, 2001. http://www.lib.ncsu.edu/theses/available/etd-20010806-202546.
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Small planar antennas are becoming increasingly popular in personal wireless communication systems since these antennas offer advantages such as small size,light weight, robust construction, ease of integration into mobile handsets, reasonable radiation efficiency and gain. A new small microstrip antenna operating at 880MHz is designed using the Finite difference time domain technique incorporating the perfectly matched-layer formulation. Shorting pins are used to achieve the reduction in size.The size of this patch antenna is approximately four times less than that of the regular half wavelength patch antenna. An antenna array made of the new patch antennas is used ina multiple antenna system to reliably separate different users on the same channel using linearbeam steering techniques with the ultimate goal of increasing the channel capacity.Prototypes of the proposed dual shorted-pin-patch antenna are fabricated and measurements of their return loss compare well with the computational results.
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Lee, Gil Young. "Conformal Body-Worn Smart Antenna System for Wideband UHF Operation." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1323756546.
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Uhl, Brecken. "Direct Spatial Antenna Modulation for Phased-Array Applications." International Foundation for Telemetering, 2009. http://hdl.handle.net/10150/606129.
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ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, NevadaNew technologies are sought to meet the requirements of evolving telemetry capabilities such as new operating bands, increased test article and ground segment collaboration, and on-the-fly quality of service (QOS) management. Smart antennas may contribute to this evolution by directing signal energy where and when it is needed. Direct spatial antenna modulation (DSAM) represents a new approach to cost-effective smart antennas potentially offering benefits such as post-amplifier modulation, polarization reconfigurability, phase-shifterless phased arrays, oscillator-less frequency conversion, and pre-receiver processing gain. The basic DSAM approach has recently been proven through analysis, simulation, and prototyping, with significant implications for future capabilities.
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Zhou, Wei. "Autonomous smart antenna systems for future mobile devices." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/9959.
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Along with the current trend of wireless technology innovation, wideband, compact size, low-profile, lightweight and multiple functional antenna and array designs are becoming more attractive in many applications. Conventional wireless systems utilise omni-directional or sectored antenna systems. The disadvantage of such antenna systems is that the electromagnetic energy, required by a particular user located in a certain direction, is radiated unnecessarily in every direction within the entire cell, hence causing interference to other users in the system. In order to limit this source of interference and direct the energy to the desired user, smart antenna systems have been investigated and developed. This thesis presents the design, simulation, fabrication and full implementation of a novel smart antenna system for future mobile applications. The design and characterisation of a novel antenna structure and four-element liner array geometry for smart antenna systems are proposed in the first stage of this study. Firstly, a miniaturised microstrip-fed planar monopole antenna with Archimedean spiral slots to cover WiFi/Bluetooth and LTE mobile applications has been demonstrated. The fundamental structure of the proposed antenna element is a circular patch, which operates in high frequency range, for the purpose of miniaturising the circuit dimension. In order to achieve a multi-band performance, Archimedean spiral slots, acting as resonance paths, have been etched on the circular patch antenna. Different shapes of Archimedean spiral slots have been investigated and compared. The miniaturised and optimised antenna achieves a bandwidth of 2.2GHz to 2.9GHz covering WiFi/Bluetooth (2.45GHz) and LTE (2.6GHz) mobile standards. Then a four-element linear antenna array geometry utilising the planar monopole elements with Archimedean spiral slots has been described. All the relevant parameters have been studied and evaluated. Different phase shifts are excited for the array elements, and the main beam scanning range has been simulated and analysed. The second stage of the study presents several feeding network structures, which control the amplitude and phase excitations of the smart antenna elements. Research begins with the basic Wilkinson power divider configuration. Then this thesis presents a compact feeding network for circular antenna array, reconfigurable feeding networks for tuning the operating frequency and polarisations, a feeding network on high resistivity silicon (HRS), and an ultrawide-band (UWB) feeding network covering from 0.5GHz to 10GHz. The UWB feeding network is used to establish the smart antenna array system. Different topologies of phase shifters are discussed in the third stage, including ferrite phase shifters and planar phase shifters using switched delay line and loaded transmission line technologies. Diodes, FETs, MMIC and MEMS are integrated into different configurations. Based on the comparison, a low loss and high accurate Hittite MMIC analogue phase shifter has been selected and fully evaluated for this implementation. For the purpose of impedance matching and field matching, compact and ultra wideband CPW-to-Microstrip transitions are utilised between the phase shifters, feeding network and antenna elements. Finally, the fully integrated smart antenna array achieves a 10dB reflection coefficient from 2.25GHz to 2.8GHz, which covers WiFi/Bluetooth (2.45GHz) and LTE (2.6GHz) mobile applications. By appropriately controlling the voltage on the phase shifters, the main beam of the antenna array is steered ±50° and ±52°, for 2.45GHz and 2.6GHz, respectively. Furthermore, the smart antenna array demonstrates a gain of 8.5dBi with 40° 3dB bandwidth in broadside direction, and has more than 10dB side lobe level suppression across the scan. The final stage of the study investigates hardware and software automatic control systems for the smart antenna array. Two microcontrollers PIC18F4550 and LPC1768 are utilised to build the control PCBs. Using the graphical user interfaces provided in this thesis, it is able to configure the beam steering of the smart antenna array, which allows the user to analyse and optimise the signal strength of the received WiFi signals around the mobile device. The design strategies proposed in this thesis contribute to the realisation of adaptable and autonomous smart phone systems.
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Haghdad, Mehdi, and Kamilo Feher. "PSEUDO ERROR DETECTION IN SMART ANTENNA/DIVERSITY SYSTEMS." International Foundation for Telemetering, 2003. http://hdl.handle.net/10150/605363.
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International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, NevadaAn implementation of a Pseudo Error Detection (PSED) system is presented and its performance in conjunction with smart antenna and smart diversity systems tested and evaluated. Non redundancy, instant response and relative simplicity make the Pseudo Error Detectors excellent real time error monitoring systems in smart antenna and smart diversity systems. Because of the Non-redundant Error Detection mechanism in Pseudo Error Detectors, we can monitor the error quality without any coding or overhead. The output of the pseudo error detector in AWGN, selective fading Doppler shift and other interference environments is directly correlated to the BER and BLER. This direct correlation makes it a great tool for online error monitoring of a system and can have numerous applications In a PSED the Eye diagram from the demodulator is sampled once per symbol. By monitoring and comparison of the eye at sampled intervals at different thresholds, we would know if an error has occurred. By integrating this result over a period of time we can get the averaged error level. The results provided in this paper were obtained and verified by both MatLab simulations using dynamic simulation techniques and hardware measurements over dynamic channels.
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Akhtman, Jos. "Smart antenna-aided multicarrier transceivers for mobile communications." Thesis, University of Southampton, 2007. https://eprints.soton.ac.uk/264048/.
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Wang, Ting. "Wireless Network Physical Layer Security with Smart Antenna." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/23243.
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Smart antenna technique has emerged as one of the leading technologies for enhancing the quality of service in wireless networks. Because of its ability to concentrate transmit power in desired directions, it has been widely adopted by academia and industry to achieve better coverage, improved capacity and spectrum efficiency of wireless communication systems. In spite of its popularity in applications of performance enhancement, the smart antenna\'s capability of improving wireless network security is relatively less explored. This dissertation focuses on exploiting the smart antenna technology to develop physical layer solutions to anti-eavesdropping and location security problems.We first investigate the problem of enhancing wireless communication privacy. A novel scheme named "artificial fading" is proposed, which leverages the beam switching capability of smart antennas to prevent eavesdropping attacks. We introduce the optimization strategy to design a pair of switched beam patterns that both have high directional gain to the intended receiver. Meanwhile, in all the other directions, the overlap between these two patterns is minimized. The transmitter switches between the two patterns at a high frequency. In this way, the signal to unintended directions experiences severe fading and the eavesdropper cannot decode it. We use simulation experiments to show that the artificial fading outperforms single pattern beamforming in reducing the unnecessary coverage area of the wireless transmitter.
We then study the impact of beamforming technique on wireless localization systems from the perspectives of both location privacy protection and location spoofing attack.
For the location privacy preservation scheme, we assume that the adversary uses received signal strength (RSS) based localization systems to localize network users in Wireless LAN (WLAN). The purpose of the scheme is to make the adversary unable to uniquely localize the user when possible, and otherwise, maximize error of the adversary\'s localization results. To this end, we design a two-step scheme to optimize the beamforming pattern of the wireless user\'s smart antenna. First, the user moves around to estimate the locations of surrounding access points (APs). Then based on the locations of the APs, pattern synthesis is optimized to minimize the number of APs in the coverage area and degenerate the localization precision. Simulation results show that our scheme can significantly lower the chance of being localized by adversaries and also degrade the location estimation precision to as low as the coverage range of the AP that the wireless user is connected to.
As personal privacy preservation and security assurance at the system level are always conflictive to some extent, the capability of smart antenna to intentionally bias the RSS measurements of the localization system also potentially enables location spoofing attacks. From this aspect, we present theoretical analysis on the feasibility of beamforming-based perfect location spoofing (PLS) attacks, where the attacker spoofs to a target fake location by carefully choosing the beamforming pattern to fool the location system. The PLS problem is formulated as a nonlinear feasibility problem, and due to its intractable nature, we solve it using semidefinite relaxation (SDR) in conjunction with a heuristic local search algorithm. Simulation results show the effectiveness of our analytical approach and indicate the correlation between the geometry of anchor deployment and the feasibility of PLS attacks. Based on the simulation results, guidelines for guard against PLS attacks are provided.
Ph. D.
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Lei, Yu. "Resource Management with Smart Antenna in CDMA Systems." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/30876.
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Third generation (3G) mobile communication systems will provide services
supporting high-speed data network and multimedia applications in addition to voice
applications. The Smart antenna technique is one of the leading technologies that helps to
meet the requirement by such services to radio network capacity. Resource management
schemes such as power control, handoff and channel reservation/assignment are also
essential for providing the seamless services with high quality. Smart antenna techniques
will help to enhance the capability of resource management through more efficient and
flexible use of resources. In this thesis, adaptive array and switched beam antenna
techniques are compared in terms of algorithm, performance, complexity and hardware
requirements. Based on these comparisons, sub-optimal code gate algorithm are most
likely the suitable algorithms for next generation code division multiple access (CDMA)
systems due to its good performances, robustness, and low complexity. A multi-cell
CDMA simulator is developed for investigating the gain from smart antenna techniques
in both bit error rate (BER) performance improvement and enhancement to resource
management schemes. Our study shows that smart antenna techniques can significantly
improve the performance of the system and help to build more powerful and flexible
resource management schemes. With eight array elements, the system capacity can be
increased by a factor of four. Power control command rates can be reduced through the
tradeoff with the interference reduction by smart antennas. Smart antennas will also
reduce handover failure rates and further increase the system capacity by reducing the
resources reserved for soft handover.Master of Science
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Chim, Kwok Chi. "Investigating the impact of smart antenna on SAR /." View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202002%20CHIM.
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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002.Includes bibliographical references (leaves 53-54). Also available in electronic version. Access restricted to campus users.
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Janapsatya, Januar. "Switched-beam smart antenna system for indoor wireless LAN /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18419.pdf.
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Chakravorti, Mark F. J. "CMOS analog signal processing for a smart antenna system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0018/MQ49671.pdf.
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Roh, Mark C. (Mark Charles) 1975. "A base station smart antenna system for CDMA cellular." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47613.
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Ng, Kok Keng. "Smart antenna application in DS-CDMA mobile communication system." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FNg.pdf.
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Wu, Ren. "Multiple-antenna wireless communications: detection and estimation with smart antennas, and space-time code design considerations." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32616.
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The main theme of this thesis is wireless communications using multiple antennas. The thesis consists of four topics on smart antenna technology, its applications to direct sequence code division multiple access (DS/CDMA) communications, and multiple-input multiple-output wireless communications. The first problem under consideration is the joint estimation of direction-of-arrival (DoA), propagation delay, and complex channel gain for antenna-array DS/CDMA communications over frequency selective multipath channels. We propose a subspace based MUSIC-type estimation algorithm which utilizes the spatial smoothing preprocessing technique. The proposed algorithm essentially breaks the multipath induced coherency within the received signals and recovers the full signal subspace spanned by the dominant signal paths of all users. This allows for the use of MUSIC-type DoA and delay estimators for individual paths of a particular user. We then describe a new criterion for detecting the number of signals impinging on a uniform linear array (ULA), which exploits eigenvector information of the sample array covariance matrix and makes explicit use of the peak information of the MUSIC spectrum. In the third part we present an iterative weight matrix approximation (IWMA) algorithm. IWMA computes an approximation to the optimum weight matrix used by weighted spatial smoothing (WSS) to completely decorrelate input sources and generate a diagonal source covariance matrix. A useful observation regarding IWMA is that the generated matrix is suitable as a basis for subspace-type DoA estimation. In the last part we discuss two deterministic measures for designing linear processing space-timeLes communications sans fil utilisant des antennes multiples constituent le thème principal de cette thèse qui traite de quatre sujets concernant la technologie des antennes intelligentes, son application aux communications à séquence directe CDMA, et des communications à entrées multiples et sorties multiples (MIMO). Le premier sujet est celui de l'estimation simultanée des directions d'arrivée, du retard de propagation et du gain complexe du canal pour des communications CDMA sur des canaux multi-trajets à fréquences sélectives. Nous proposons un algorithme d'estimation de type MUSIC à base de sous-espaces, utilisant un prétraitement par lissage spatial. L'algorithme proposé brise essentiellement la cohérence induite par les trajets multiples pour recouvrer entièrement le sous-espace du signal créé par les signaux dominants de tous les utilisateurs. Ceci permet l'utilisation d'estimateurs MUSIC des directions d'arrivée et du retard pour les signaux d'un utilisateur donné. Nous décrivons un nouveau critère pour détecter le nombre de signaux captés sur un réseau d'antennes uniforme et linéaire qui exploite le vecteur propre de la matrice de covariance des échantillons et qui utilise l'information des pics de spectre de MUSIC. Troisièmement, nous présentons un algorithme itératif d'approximation de la matrice des poids (IWMA) qui calcule une approximation de la matrice des poids optimale utilisée pour le lissage spatial (WSS), afin de complètement décorréler les sources d'entrées. Avec IWMA la matrice qui est générée peut être utilisée comme base de l'estimation de type sous-espace des directions d'arrivée. Nous discutons finalem
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Öström, Erik. "BUILDING AND EXPERIMENTALLYEVALUATING A SMART ANTENNA FOR LOWPOWER WIRELESS COMMUNICATION." Thesis, Mälardalen University, School of Innovation, Design and Engineering, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-9661.
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In wireless communication there is commonly much unnecessarycommunication made in directions not pointing towards the recipient. Normallyomni directional antennas are being used which sends the same amount ofenergy in all directions equally. This waste of energy reduces the lifetime ofbattery powered units and causes more traffic collisions than necessary. Oneway of minimizing this wasted energy and traffic collisions, is to use anothertype of antenna called “smart antenna”. These antennas can use selectableradiation patterns depending on the situation and thus drastically minimize theunnecessary energy waste. Smart antennas also provide the ability to sense thedirection of incoming signals which is favorable for physical layout mappingsuch as orientation.This thesis presents the prototyping of a new type of smart antenna called theSPIDA smart antenna. This antenna is a cheap to produce smart antennadesigned for the 2.4 GHz frequency band. The SPIDA smart antenna can usesixty-four different signal patterns with the control of six separate directionalmodes, amongst these patterns are six single direction patterns, an omnidirectionalsignal pattern and fifty-six combi-direction patterns. The thesispresents complete building instructions, evaluation data and functional driversfor the SPIDA smart antenna.
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Majeed, Haris, Rahim Umar, and Arslan Ali Basit. "Smart Antenna - MIMO, OFDM and Single Carrier FDMA for LTE." Thesis, Linnéuniversitetet, Institutionen för datavetenskap, fysik och matematik, DFM, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-12328.
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With the evolution in the telecommunication generations, more and more research is going on in the field of wireless communications. The purpose of these researches has always been to provide good network coverage across the region with higher data rates, accuracy and better performance. Control on coverage and performance has always been in focus and is achieved using better and better antennas. Research has brought us with a sophisticated approach on the control of the properties of the antennas – introduction to Smart Antennas. Smart antennas can be used to support any radio based telecommunication system in any band, with the same level of performance. Several techniques are used to get good performance out of the antennas’ system. One impressive way is the usage of multiple antennas techniques. The approach is to transmit and receive 2 or more unique data on a single radio channel. To increase the diversity gain with the use of multiple input multiple output (MIMO), OFDM is a good technology used at the physical layer. It provides robustness to frequency selective fading, high spectral efficiency and low computational complexity. So MIMO-OFDM generates a good basis for 3GPP (3rd Generation Partnership Project) and 4G telecommunication technologies as well as other wireless communications systems. With MIMO-OFDM as basis, different standards like WiMAX (Wireless Interoperability for Microwave Access) and LTE (Long Term Evolution) have been implemented now. The use of OFDM has some limitations when it is considered for uplink like high peak to average power ratio (PAPR), for which a new technique of using Single Carrier is considered for uplink. Single Carrier FDMA has same advantages as of OFDM with low PAPR. In this thesis, we investigate the smart antennas with its application as LTE with the study of MIMO-OFDM and Single Carrier FDMA Systems. Performance of MIMO OFDM and SC-FDMA is evaluated by using simulations on MATLAB.
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Shad, Faisal. "SDMA/TDMA dynamic slot assignment using a smart antenna basestation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0030/NQ66294.pdf.
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Ellinger, Frank. "Monolithic integrated circuits for smart antenna receivers at C-Band /." Konstanz : Hartung-Gorre, 2001. http://www.loc.gov/catdir/toc/fy055/2001422287.html.
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Kavak, Adnan. "Vector propagation channel studies for smart antenna wireless communication systems /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004302.
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Varada, Shanmukha Shri Sri. "Neural Networks and Smart Antennae : A Case Study." Thesis, University of Skövde, School of Humanities and Informatics, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-981.
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This dissertation evaluates the artificial neural technique for evolving a smart antenna system. The AI techniques pose a challenging research in the field of communication. As such the antennas help to communicate with the digital processor to choose the desired signals and reject the others. It makes its own decision even to find the level of interferences and noises to be discarded by amplitude elimination process through the use of perceptron optimization algorithms like LMS (Least Mean Squares). This method helps to enhance the performance of signal processing efficiently. The design of hardware and software are quite complex. This is due to the fact, that the behaviour of the system is not fully understood being a real-time dependent system. This research work is carried only on software with certain simulated activity on beam-formation algorithm and as well, the system responses before and after using the adaptive algorithm. In this report, we try to concentrate to work on the method of adaptivity to make antenna adaptable to a virtual form of real-time environment. For, this reason a two-element antenna is used for simulation testing, as it is the most commonly used antenna for all purposes in communication. It is also tested on various scanning levels of rotation to determine the learning rate (a parameter that has no effect on the radiation output after using LMS) mean-square error rates and convergence analysis. For the purpose of above mentioned tests, three hypotheses are framed in relation to side-lobe reduction level above 5 decibels, the narrowing of the beam after adaptivity and finally the response of the main beam output for varying values of learning rate, respectivelty. The given research work, may comprehend good practical use of this LMS algorithm and also to indicate antenna patterns and the responses to adaptivity conditions through clarity in graphical format.
The method is influenced to reduce computational complexity and bring simplicity to the functionality of the antenna with more efficient and effective adaptivness. An effort to test theoretical concepts in practice is also been made in this thesis work. The results show that the antenna system can be made to evolve itself through the process of adaptation with simple behaviour by relying on artificial intelligence technique which ensures little supervision and human intereference. Eventually, it is understood that the reader should have possessed prior concepts, related to antennas, digital signal processing and its practical usage in artificially intelligent systems and as well the exceptions in it, since the work is explained in the direct level assuming so.
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Sundaresan, Karthikeyan. "Network Protocols for Ad-Hoc Networks with Smart Antennas." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14122.
Full textAbstract:
Multi-hop wireless networks or ad-hoc networks
face several limiting characteristics that make it difficult to support a multitude of applications. It is in this context that we find smart antennas to find significant applications in these networks, owing to their ability to alleviate most
of these limitations. The focus of my research is thus to investigate the use of smart antennas in ad-hoc networks and hence efficiently design network protocols that best leverage their capabilities in communication. There are two parts to the proposed objective of designing efficient network protocols that pertain to the nature of the smart antenna network considered, namely, homogeneous and heterogeneous smart antenna networks.
Unlike heterogeneous smart antenna networks, where different devices in the network employ different antenna technologies, homogeneous smart antenna networks consist of devices employing the same antenna technology. Further, in homogeneous smart antenna networks, different antenna technologies operating in different strategies tend to perform the best in different network architectures, conditions and application requirements. This
motivates the need for developing a {em unified} framework for designing efficient communication (medium access control and routing) protocols for homogeneous smart antenna networks in general. With the objective of designing such a unified framework, we start by designing efficient MAC and routing protocols for the most sophisticated of the smart antenna technologies, namely multiple-input multiple-output (MIMO) links. The capabilities of MIMO links form a super-set of those possible with other antenna technologies. Hence, the insights gained from the design of
communication protocols for MIMO links are then used to develop unified MAC and routing frameworks for smart antennas in general.
For heterogeneous smart antenna networks, we develop theoretical performance bounds by studying the impact of increasing degree of heterogeneity on network throughput performance. Given that the
antenna technologies are already unified in the network, unified solutions are not required. However, we do develop efficient MAC and routing protocols to best leverage the available heterogeneous capabilities present in the network. We also design efficient cooperation strategies that will further help the communication protocols in exploiting the available heterogeneous capabilities in the network to the best possible extent.
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Varum, Tiago Miguel Valente. "Nonuniform 2D microstrip antenna arrays for wireless applications." Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17373.
Full textAbstract:
Doutoramento em Engenharia ElectrotécnicaWireless communications have undergone over the last decades a tremendous progress as a consequence of the exponential growth in demand for mobile devices, and nowadays are more and more involved in people's lives. This presence is re ected through the use of a large number of applications of which they become increasingly dependent on. The antenna, in its most di erent forms, are crucial elements in the establishment this type of communication. Each application involves a number of speci c characteristics, whereby, the improvement of wireless communications is related to the appropriateness of the used antenna. Many applications require antennas with radiation pattern with its particular shapes (in terms of beamwidth, side lobes levels, direction, etc ..), static or dynamic (adaptive antennas), involving in most cases the use antenna arrays to meet to such constraints. In this thesis, a number of techniques to synthesize antennas consisting of planar arrays with nonuniform excitation of their elements, are addressed. A group of the direction of arrival and beamforming estimation algorithms are also presented and analyzed, in order to enable their application in adaptive antenna array with dynamic beamforming. A vast and diversi ed set of arrays with di erent radiation requirements, and for di erent applications were developed. These arrays have great applicability in current research topics in antennas, such as vehicle communications, Wi-Fi in sports venues and smart antennas.
As comunicações sem os têm sofrido, ao longo das ultimas décadas, um enorme progresso em consequência do aumento exponencial da procura de dispositivos móveis, estando hoje em dia cada vez mais presentes na vida das pessoas. Esta presença re ete-se através do uso de um elevado número de aplicações das quais se tornam cada vez mais dependentes. As antenas, nas suas mais diversi cadas formas, são elementos cruciais no estabelecimento deste tipo de comunicações. Cada aplicação envolve um conjunto de características especí cas, pelo que a melhoria das comunica ções sem os está relacionada com a adequação da antena usada. Muitas aplicações necessitam de antenas com diagramas de radiação com formatos próprios (em termos de larguras de feixe, níveis de lobos secund ários, direção, etc..), sejam eles estáticos ou dinâmicos (antenas adaptativas), implicando na maioria dos casos o uso de agregados de antenas para fazer face a tais condições. Nesta tese são abordadas várias técnicas de desenho de antenas constituídas por agregados planares, com alimentação não uniforme dos seus elementos. Um conjunto de algoritmos de estimação dos ângulos de chegada e de formação de feixe são também apresentados e analisados com vista à sua aplicação em agregados de antenas adaptativas, com formação de feixe dinâmico. Um vasto e diversi cado conjunto de agregados com diferentes requisitos de radiação, destinados a diferentes aplicações foram desenvolvidos. Estes agregados têm grande aplicabilidade nos atuais tópicos de investiga ção em antenas, tais como as comunicações veiculares, Wi-Fi em espaços desportivos e smart antenas.
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Noordin, Nurul Hazlina. "Adaptive array antenna design for wireless communication systems." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8950.
Full textAbstract:
Adaptive array antennas use has been limited to non-commercial applications due to their high cost and hardware complexity. The implementation cost of adaptive array antennas can be kept to a minimum by using cost effective antennas, reducing the number of elements in the array and implementing efficient beamforming techniques. This thesis presents techniques for the design of adaptive array antennas which will enable their cost effective implementation in wireless communication systems. The techniques are investigated from three perspectives, namely, reconfigurable antenna design, wide scan array design and single-port beamforming technique. A novel single-feed polarisation reconfigurable antenna design is proposed in the first stage of this study. Different polarisation states, namely, linear polarisation (LP), left-hand circular polarisation (LHCP) and right-hand circular polarisation (RHCP), are achieved by perturbing the shape of the main radiating structure of the antenna. The proposed antenna exhibits good axial ratio (< 3 dB at 2.4 GHz) and has high radiation efficiency in both polarisation modes (91.5 % - LHCP and 86.9 % - RHCP). With a compact single feeding structure, the antenna is suitable for implementation in wireless communication devices. The second stage of the study presents the design procedure of wide scan adaptive array antennas with reduced number of elements. Adaptive array antennas with limited number of elements have limited scanning range, reduced angular scanning resolution and high sidelobe levels. To date, design synthesis of adaptive array antennas has been targeted on arrays with a large number of elements. This thesis presents a comprehensive analysis of adaptive array antennas with less than 10 elements. Different array configurations are analysed and various array design parameters such as number of elements, separation between elements and orientation of the elements are analysed in terms of their 3 dB scan range. The proposed array, the 3-faceted array, achieves a scanning range up to ±70°, which is higher than ±56° obtained from the Uniform Linear Array. The faceted arrays are then evaluated in the context of adaptive beamforming properties. It was shown that the 3-faceted array is suitable for adaptive array applications in wireless communication systems as it achieves the highest directivity compared to other faceted structures. The 3-faceted array is then synthesised for low sidelobe level. Phase correction together with amplitude tapering technique is applied to the 3-faceted array. The use of conventional and tuneable windowing techniques on the 3- faceted array is also analysed. The final stage of the study investigates beamforming techniques for the adaptive array antenna. In the first part, beamforming algorithms using different performance criteria, which include maximum signal-to noise-ratio (SINR), minimum (mean-square Error) MSE and power minimisation, are evaluated. In the second part, single-port beamforming techniques are explored. In previous single-port beamforming methods, the spatial information of the signals is not fully recovered and this limits the use of conventional adaptive beamforming algorithms. In this thesis, a novel signal estimation technique using pseudo-inverse function for single-port beamforming is proposed. The proposed polarisation reconfigurable antenna, the 3-faceted array antenna and the single-port beamforming technique achieve the required performance, which suggests the potential of adaptive array antennas to be deployed commercially, especially in wireless communication industry.
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Bobor-Oyibo, Freeborn. "Dynamic capacity enhancement using a smart antenna in mobile telecommunications networks." Thesis, Northumbria University, 2012. http://nrl.northumbria.ac.uk/5840/.
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This work describes an investigation into the performance of antennas for mobile base station applications and techniques for improving the coverage and capacity within a base station cell. The work starts by tracing the development of mobile systems, both in technical and commercial terms, from the earliest analogue systems to present day broadband systems and includes anticipated future developments. This is followed by an outline of how smart antenna systems can be utilised to improve cell coverage and capacity. A novel smart antenna system incorporating an array of slant ± 450 dual- polarised stacked patch elements four columns wide excited by a novel multi-beam forming and beam shaping network has been designed, simulated and implemented. It is found that for an ideal smart antenna array, four narrow overlapping beams, one wide “broadcast channel” beam and right and left shaped beams can be provided. Results are presented for the simulation of the smart antenna system using CST EM simulation software which inherently includes mutual coupling and the effects of a truncated ground plane on the element patterns. The results show some significant changes to the desired set of coverage patterns and various mutual coupling compensation techniques have been reviewed. An improved design technique has been developed for compensating the performance degrading effects of mutual coupling and finite ground plane dimensions in microstrip antenna arrays. The improved technique utilises combination of two previously known techniques: complex excitation weights compensation by inversion of the array mutual coupling scattering matrix and the incorporation of a WAIM (wide angle impedance matching) sheet. The technique has been applied to a novel multi-beam smart antenna array to demonstrate the efficacy of the technique by electromagnetic simulation. In addition, a demonstrator array has been constructed and tested which has yielded a positive conformation of the simulation results. For the developed demonstrator array which provides seven different beams, beams “footprints” have been predicted both for free space propagation and for urban propagation to evaluate the dynamic capacity performance of the smart antenna in a 3G mobile network. The results indicate that sector capacity can be dynamically tailored to user demand profiles by selection of the appropriate beam patterns provided by the novel smart antenna system.
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Schacht, Mirko [Verfasser]. "System Performance Gains from Smart Antenna Concepts in CDMA / Mirko Schacht." Aachen : Shaker, 2005. http://d-nb.info/1181620074/34.
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Torlak, Murat. "Estimation and capacity of channels in smart antenna wireless communication systems /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Ng, Stewart Siew Loon. "Smart antenna in DS-CDMA mobile communication system using circular array /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Mar%5FNg.pdf.
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Wang, Ru-San, and 王如森. "Mobile Smart Antenna." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/48320087242482300009.
Full textAbstract:
碩士元智大學
通訊工程學系
95
The purpose of this essay is to develop a low-cost intelligent antenna which can be installed on mobile vehicle and receive digital TV programs. Using an singl-chip 8052 as a host controller to make a step-motor to rotate 360-degree, a one-directional antenna is located on a turntable which is driven to rotate by the step-motor.First,the antenna scans an energy of every angle and transforms the energy which is analog data into digital data, and then sends the data to the host controller to arbitrate.After the host controller determines the widest azimuth. the antenna turns to the widest direction and finishs the scan-action.Finally,empolying the oriented character of an electronic compass, the antenna can adjust to the way of the target automatically to trace. The way of the experiment is,first,to use signal generator (E4421B) emitting a 570MHz and +10dBm signal to simulate a signal source of a TV station and record received signal data from a 100 cm distance to the source. Then,turn the antenna to any direction to see whether the antenna can adjust to the widest direction automatically.Finally,the received signal is through Power divider. Parts of the enengy of the signal are used to compare and the rest of the enengy are connected to top on box to receive TV programs.
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Kao, Meng-Hua, and 高孟華. "Smart Antenna for WCDMA Systems." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/28614832104943970371.
Full textAbstract:
碩士國立臺灣大學
電信工程學研究所
89
For the 3rd Generation Partnership Project (3GPP)’s WCDMA uplink communications, scrambling is introduced in the dedicated physical channels (DCH). A specially designed matched filter, whose coefficients are a combination of the Orthogonal Variable Spreading Factor (OVSF) code and the scrambling code for the desired user, is employed to carry out the despreading and unscrambling simultaneously. Channel estimation taking advantages of the coherent integration and incoherent integration operations to enhance signal power and suppress interference at the same time, therefore improves the estimates. Besides, smart antennas hold great promise for increasing the capacity depending on radiating and receiving energy only in the intended directions. The spatial diversity is well taken by smart antennas with Digital BeamForming (DBF). The Fast Fourier Transform (FFT)-based beam-space beamforming gets the Direction-Of-Arrival (DOA) by collecting signals in a time slice; otherwise, the Minimum-Mean-Square- Error (MMSE)-based adaptive beamforming decides the weights by minimizing the mean square errors between the signals and the scrambling code. Compare these two approaches of beamforming in Signal-to-Interference and Noise Ratio (SINR) analysis to evaluate the system performance, as smart antenna is employed on WCDMA. Simulation results show that adaptive antenna provides feasible implementation.
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Lin, He-Shang, and 林合聲. "2.4GHz smart antenna transmission applications." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/68417998110671688799.
Full textAbstract:
碩士中原大學
電子工程研究所
103
With the rapid development of wireless communication demand, rapid increase in multimedia communication, the next generation of wireless communications technology necessary to meet the high-speed, high-capacity, high-quality and high elasticity of demand for the use of the urgent need to use the spectrum by means of high-efficiency technology supports, therefore, the wireless communication system should give special consideration to "wireless access (Radio Access) capability" promotion, hoping to achieve the best efficiency of spectrum use; in many technologies, the smart antenna (Smart Antenna) technology that for enhancing the efficiency of spectrum resources, system capacity and communications products effective way, however, the high cost of smart antenna design products available in the market, the switching speed is slow, therefore, we used the geometric matrix antenna design, vertical polarization and horizontal polarization design 1200 kinds of antenna pattern combinations, although only 8dBi antenna gain energy, and there are up to 24dBi anti-jamming capability, but such a design, through antenna pattern switching, automatic channel selection, under flow control mechanism, the performance of the product, At least a 30% increase, a large 360-degree coverage Hassle service. From the experimental results, we have a large swimming pool hall, a large office environment to authenticate with the next quarters, through the transfer software to monitor the transmission rate is relatively lower, not on the transmission rate, anti-interference ability are superior to other designs, can be used to design a user leaving adopted.
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Chiang, Ming-Hsu, and 江明緒. "Smart High-Gain Yagi Antenna." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/65098794405572659416.
Full textAbstract:
碩士中華大學
電機工程學系碩士班
102
In this thesis, we utilize HFSS to design two types of Smart High-gain Yagi antennas with three 120-degree sectors. Each sector consists of dipole antenna, director and reflector elements on an FR4 substrate. The first Smart high-gain Yagi antenna works for 2.4~2.5GHz with return loss of 13.3dB at 2.45GHz and 200MHz bandwidth. The antenna peak gain was is about 7.5dBi. The second antenna,a miniaturized high-gain Yagi antenna, is the upgraded version of the first antenna which is with 16dB return loss and peak gain of 7.5dBi at 2.45GHz. The content of this thesis includes smart Yagi antenna design, miniaturized antenna design, simulation and measurement results. Final work shows good consistency both with simulation and practical measurement results.
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Banaser, Hesham Hassan. "High Performance WLAN Using Smart Antenna." Thesis, 2007. http://hdl.handle.net/10012/3303.
Full textAbstract:
The need for higher data rates in WLANs boosts drastically because tremendous consumer interest in emerging multimedia applications, such as HDTV, has been increased. Currently, the IEEE 802.11a/b/g WLANs provide a limited data rate for the current user application requirements. In order to overcome substantial limitations of the existing WLANs, the next generation of WLANs, IEEE 802.11n, is in the course of development and expected to support higher throughput, larger coverage area and better QoS. The high performance IEEE 802.11n WLAN can improve data rate significantly by using smart antenna systems in the physical layer to take advantage of multi-path fading of wireless channels.
In this thesis, an analytical model is developed to study the MAC performance and
the underlying smart antenna technologies used in multi-path fading channels. Multiple
antennas employed in the AP arise two popular approaches to provide a significant performance improvement, diversity and multiplexing. Considering the diversity gain of multiple antennas at the AP in which the AP with multiple antennas serves one user at a time, the capacity and throughput can be obtained. In addition, the AP is possible to serve multiple users in the downlink, by exploiting the multiplexing gain of the wireless channel. We investigate the maximum network throughput when the traffic intensity of the AP approaches to one. Unlike most of previous research which focus on either the physical or the MAC layer performance, our analytical model jointly considers the MAC protocol and the smart antenna technology.
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蔣鎮鴻. "Antenna Design of Smart Wearable Device." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5sh5jr.
Full textAbstract:
碩士國立聯合大學
電子工程學系碩士班
106
In this experiment, three antennas were designed for wearable device by using electromagnetic simulation software HFSS. Exporting graphics from AutoCAD, after exposure、development、etching、removing photo resistor. Finally, we use the network analyzer to measure characteristics of these propose antenna. In this experiment, one triple-band inverted-F antenna was designed at the GPS(1.575GHz), LTE Band1(2.11－2.17GHz), Wi-Fi (2.4 GHz) application for smart watch；one dipole antenna wsa developed at the Bluetooth (2.45 GHz), Wi-Fi (5.25－5.35 GHz) be used for multifunction Bluetooth headset；and the others co-planer waveguide (CPW) antenna was proposed at the Bluetooth (2.45 GHz) be used for multifunction Bluetooth ring.Finally, three different antennas manufacture on the FR4 substrate and the characteristics of these antennas were also investigated.
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ZHUO, TING-YAN, and 卓廷彥. "Antenna design for smart watch devices." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/657hbp.
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碩士南臺科技大學
電子工程系
106
This thesis proposes two designs of antennas for smart watch devices. First one is a WLAN MIMO antennas for smart watch applications; second one is a design with antenna on smart watch for LTE/DCS/PCS/UMTS application. First one is the design of WLAN MIMO antennas for smart watch applications. The overall dimensions of the MIMO antenna design are 41 × 41 × 4.8 mm3, with a ground plane size of 35 × 35 mm2. In this case, a dual-band MIMO antennas for smart watch operating at WLAN 2.4/5.2/5.8 GHz bands is proposed. The antenna design uses loop structure to achieve the design goal. In order to achieve desirable dual-band WLAN operation, an inductor chip is connected in series between the loop arm and the system ground. Second one is the design with antenna on smart watch for LTE/DCS/PCS/UMTS application. The overall dimensions of the MIMO antenna design are 40 × 40 × 12.8 mm3, with a ground plane size of 40 × 40 mm2. The design can contain the application bands of LTE/DCS/PCS/UMTS. The antenna use the PIFA structure. The longest path extends from the planar architecture to the frame, and then the copper strip is added to the upper edge of the frame to match the application frequency bands.
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Liao, Raymond, and 廖國瑞. "Design and Implementation of IEEE 802.11 Smart Antenna System Using Yagi Antennas." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/17492540621416343171.
Full textAbstract:
碩士國立中央大學
通訊工程學系在職專班
102
This thesis is the implementation of a modified dipole antenna designed on circular disk at frequency 2.4GHz band. By using the principle of Yagi antenna, the directional beam is generated. Four antennas were developed to cover four quadrants at horizontal polarization, and another four antennas were developed to cover four quadrants at vertical polarization. They could be combined into an antenna with a total of eight quadrants radiation pattern including vertical and horizontal polarization similar to circularly polarized antenna. It covers all directions to meet the application of Smart Antenna System. This is a simple, easy-making, low-cost method to use printed circuit board for this implementation. The circular Yagi antenna assembled with three PCBs and the size is about 88.44 × 88.44 × 41.6 mm3. Detail content of the antenna design and experiment result is discussed in this paper.
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De, Kuo Ren, and 郭仁德. "Design of 2.4GHz Smart Antenna System Testbed." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/89717646372452611148.
Full textAbstract:
碩士中原大學
電子工程學系
88
In wireless communication, smart antenna system can be used to suppress multipath fading by antenna diversity and increase system capacity by supporting multiple cochannel users in reception and transmission. The purpose of this thesis is to design a testbed, which has the function of smart antenna system. This testbed is helpful for the research, evaluation and provability of smart antenna system algorithm and vector propagation channel modeling. First, we''re going to introduce the specifications of this system, also the circuit design and fabrication for the three main modules (RF module, Baseband module and Common module), which comprise this testbed. The RF module consists of transmitter and receiver unit . Most of the components in the above unit have been tested and meet the specifications. The Baseband module consists of DAQ unit and I/O interface. Circuits of DAQ unit have been designed and realized. Also the control programs between I/O interface and the control unit of common module have been finished and an elementary test has been done. The Common module consists of synthesizer, control unit and mother broad. The synthesizer has been realized and tested, and the circuits of mother broad have been designed well.
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Wu, Ming-shan, and 吳明珊. "Smart Antenna Array for Mobile Internet Application." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/p94h4p.
Full textAbstract:
碩士國立中央大學
電機工程學系
102
The target of this study is to develop a smart antenna array for mobile communication application, so as to improve the transmission efficiency and interference suppression. The center frequency of 2.4 GHz is chosen, which is one of the ISM band (Industrial Scientific Medical Band) and is commonly used for WLAN (IEEE 802.11b / IEEE 802.11g), Bluetooth, and ZigBee applications. Most of the conventional antenna designs for mobile application are omnidirectional ones because the signal may come from any direction. However, this does not lead to optimal data transmission performance and the antenna will also receive interferences from all directions. Since the wanted signal comes from a particular direction only, we propose an antenna array for mobile devices, in which the relative phases of the antenna elements are varied in a way that the main beam of the radiation pattern can be set to the desired direction with suppression of undesired interferences from other directions. This work employs a 2×2 patch antenna planar array on a PCB (printed circuit board) size of 200 mm ×137.5 mm, which is about the size of a 7.9 inch tablet. The relative phase of the antenna feed is controlled by digital phase shifters. The main beam of proposed antenna array can be set to four directions, which are the east, west, south, and north sides. The measured bandwidth for 10 dB return loss is about 4.6%, with a peak gain of 1 dBi and a HPBW (half-power beam width) of about 50 degree. It can be applied to the back of tablet of size larger than 7.9 inch for improving the transmission efficiency and interference suppression.
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Lin, Shi-Ger, and 林士哲. "Design and Simulation of Smart Antenna Algorithms." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/19990902038691843450.
Full textAbstract:
碩士國防管理學院
國防資訊研究所
89
In the last few years, because the telecommunication market develop quickly, make mobile customer population rapidly increase. However, the limited bandwidth resource of the radio communication system results in current communication system can't bear and cause congestion. To meet increasing consumers demands and solve the congestion problem of the current system, smart antenna is a quite good solution. In smart antenna system, adaptive equalization and adaptive beamforming technology play very critical roles. Therefore, the algorithm that smart antenna use will affect performance of antenna system. As to the now standard algorithm, for example: LMS, RLS, CMA, the DD algorithm…etc, they can only provide limited ability, and as to some new algorithms, they are computational complexity. Consequently, we propose using a hierarchical scheme to improve the ability of the above algorithm and to reduce computational complexity. According as our actual simulation and evaluation prove the algorithm that use hierarchical scheme better than standard algorithm.
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Wang, Wu-Chi, and 王吳祺. "Study on MultiUser Detection with Smart Antenna." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/66244763774813671434.
Full textAbstract:
碩士國立中山大學
通訊工程研究所
91
Smart antenna, which weights are obtained by Wiener solution, would suppress some undesired interference signals in spatial domain. The other interference signals that cannot be suppressed by smart antenna or caused by near-far effect will be post-processed by multiuser detectors. In the proposed algorithm, the cross-correlation matrix of desired signal and received signal from smart antenna algorithm would be applied to multiuser detector to reduce the complexity. From computer simulation results, the proposed algorithm has lower complexity and better BER performance than separate smart antenna or multiuser detection algorithms. Detail derivations of complexity and BER performance are also provided in this thesis.