Download or read book Transmission Strategies Employing Multiple Antennas for TheDownlink of Multi Carrier CDMA Systems written by Thomas Sälzer and published by . This book was released on 2004 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multi-Carrier CDMA (MC-CDMA) combining multi-carrier modulation and spreading in the frequency domain is a promising candidate for new air interfaces of future mobile radio systems. This thesis explores the potential of multiple antenna technologies for the downlink of an MC-CDMA system. Space-frequency transmit filtering is proposed for the case where instantaneous knowledge of the channel fading is available at the basestation. This approach can optimally exploit the spatial diversity of the channel and efficiently mitigate the multiple access interference. When only covariance knowledge is available, we propose transmit beamforming with direction-based spreading code assignment. This technique benefits from the antenna gain and from an implicit reduction of the interference. Both transmission strategies lead to an increased user capacity and simultaneously allow a transfer of implementation complexity from the mobile terminal to the basestation.

Download or read book Multi Carrier Spread Spectrum written by Khaled Fazel and published by Springer Science & Business Media. This book was released on 2006-08-12 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aims to edit the ensemble of the contributions and research results in this field that have been presented during the 5th International Workshop on Multi-Carrier Spread-Spectrum (MC-SS 2005), held in Oberpfaffenhofen, Germany.

Download or read book Multi Carrier Spread Spectrum written by Khaled Fazel and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 515 pages. Available in PDF, EPUB and Kindle. Book excerpt: The benefits and success of multi-carrier (MC) modulation on one side and the flexibility offered by the spread spectrum (SS) technique on the other side have motivated many researchers to investigate the combination of both techniques since 1993. This combination known as multi-carrier spread spectrum (MC-SS) benefits from the advantages of both systems and offers high flexibility, high spectral efficiency, simple detection strategies, narrow-band interference rejection capability, etc. The basic principle of this combination is straightforward: The spreading is performed as direct sequence spread spectrum (DS-SS) but instead of transmitting the chips over a single carrier, several sub-carriers are employed. The MC modulation and demodulation can easily be realized in the digital domain by performing IFFT and FFT operations. The separation of the users' signals can be performed in the code domain. MC-SS systems can perform the spreading in frequency direction, which allows for simple signal detection strategies. Since 1993, MC-SS has been deeply studied and new alternative solutions have been proposed. Meanwhile, deep system analysis and comparison with DS-CDMA have been performed that show the superiority of MC-CDMA.

Download or read book Multi antenna Systems and Interconnection Strategies for CDMA Wireless Access Networks written by Halim Yanikö meroglu and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this thesis is to utilize antennas in novel ways so as to achieve performance benefits at the system level through spatial interference management. To this end, we study CDMA multi-antenna wireless access networks (where the transmission and reception are through multiple antennas distributed in the service area), and compare their performance with that of the conventional networks where only one central antenna (CA) exists. We first demonstrate that by using CDMA distributed antenna (DA), the power control dynamic range can be reduced significantly; this yields a notable reduction in the outage. The DA system simulates a hypothetical optimal CA system; therefore, even though the capacity of a DA system may be considerably higher than that of a CA type, the capacity is still low per antenna element (AE). In order to overcome this shortcoming, we present the sectorized distributed antenna (SDA) system, where each AE is connected to a separate feeder. We further suggest a novel nonlinear power control algorithm which balances the SIR in SDA systems. We demonstrate analytically and through simulations that in a CDMA SDA system the reverse link capacity increases approximately linearly with increasing numbers of AE's. This increase is still valid, despite the overlapping antenna patterns and non-uniform traffic, due to the joint decoding (enhanced macrodiversity) capability of the SDA system, and also to the effective power control algorithm used. Therefore, the reverse link capacity of an SDA system with ' L' AE's is higher than that of an 'L'-cell duster serving the same region. In order to achieve maximum performance from the SDA architecture, the interference picked up by an AE for a user should be uncorrelated with those picked up by other AE's. To this end, the conditions, under which the correlated interference occurs, are evaluated, and the effects of the system parameters on the correlation are analyzed. Finally, AE interconnection strategies are studied in order to determine cost-efficient as well as robust and flexible interconnection architectures, by using results from the theory of minimal networks, especially those on Steiner trees.

Download or read book Multi Carrier and Spread Spectrum Systems written by Khaled Fazel and published by John Wiley & Sons. This book was released on 2008-09-15 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The technological progress in multi-carrier (MC) modulation led orthogonal frequency division multiplexing (OFDM) to become an important part of beyond 3G cellular mobile communication standards, including LTE and WiMAX. In addition, the flexibility offered by the spread spectrum (SS) and time division multiplexing (TDM) techniques motivated many researchers to investigate several MC combined multiple access schemes, such as MC-CDMA, OFDMA and MC-TDMA. These schemes benefit from the advantages of each sub-system and offer high flexibility, high spectral efficiency, simple detection strategies and narrow-band interference rejection capability. Multi-Carrier and Spread Spectrum Systems is one of the first books to describe and analyze the basic concepts of multi-carrier OFDM transmission and its combination with spread spectrum (MC-CDMA). The different architectures and detection strategies as well as baseband-related transceiver components are explained. This includes topics like FEC channel coding and decoding, modulation and demodulation (IFFT/FFT), digital I/Q-generation, time and frequency synchronisation, channel estimation, frequency domain equalization and RF aspects such as phase noise and non-linearity issues. Concrete examples of its applications for cellular mobile communication systems (B3G/4G) are given. Further derivatives of MC-SS (such as OFDMA, SS-MC-MA and DFT-spread OFDM) and their corresponding applications in the LTE, WiMAX, WLAN and DVB-RCT standards are detailed. Capacity and flexibility enhancements of multi-carrier OFDM systems by different MIMO diversity techniques such as space time/frequency coding (STC, SFC) and software defined radio concepts are also described. Written in a highly accessible manner this book provides a unique reference on the topics of multi-carrier and spread spectrum communications, assisting 4G engineers with their implementation. Fully updated new edition of successful text, including two new chapters on LTE and WiMAX Describes in detail new applications of OFDM in mobile communication standards Examines all multi-carrier spread spectrum schemes, with in-depth analysis, from theory to practice Introduces the essentials of important wireless standards based on multi-carrier/spread spectrum techniques.

Download or read book Multi Carrier Spread Spectrum Related Topics written by Khaled Fazel and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Khaled Fazel Stefan Kaiser Digital Microwave Systems German Aerospace Center (DLR) Bosch Telecom GmbH Institute for Communications Technology D-71522 Backnang, Germany D-82234 Wessling, Germany In this last decade of this millennium the technique of multi-carrier transmission for wireless broadband multimedia applications has been receiving wide interests. Its first great success was in 1990 as it was selected in the European Digital Audio Broadcasting (DAB) standard. Its further prominent successes were in 1995 and 1998 as it was selected as modulation scheme in the European Digital Video Broadcasting (DVB-T) and in three broadband wireless indoor standards, namely ETSI-Hiperlan-II, American IEEE-802. 11 and Japanese MMAC, respectively. The benefits and success of multi-carrier (MC) modulation in one side and the flexibility offered by spread spectrum (SS) technique in other hand motivated many researchers to investigate the combination of both techniques, known as multi-carrier spread-spectrum (MC-SS). This combination benefits from the main advantages of both systems and offers high flexibility, high spectral efficiency, simple detection strategies, narrow band interference rejection capability, etc. . The basic principle of this combination is straightforward: The spreading is performed as direct SS (DS-SS) but instead of transmitting the chips over a single sequence carrier, several sub-carriers could be employed. As depicted in Figure 1, after spreading with assigned user specific code of processing gain G the frequency mapping and multi-carrier modulation is applied. In the receiver side after multi-carrier demodulation and frequency de-mapping, the corresponding detection algorithm will be performed.

Download or read book Performance of Multi carrier CDMA Systems with Multiple Antennas written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Vi, 90 leaves : ill. ; 30 cm.

Download or read book Mobile Broadband Multimedia Networks written by Luis M. Correia and published by Elsevier. This book was released on 2010-07-26 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mobile Broadband Multimedia Networks: Techniques, Models and Tools for 4G provides the main results of the prestigious and well known European COST 273 research project on the development of next generation mobile and wireless communication systems. Based on the applied research of over 350 participants in academia and industry, this book focuses on the radio aspects of mobile and wireless broadband multimedia communications, by exploring and developing new methods, models, techniques, strategies and tools towards the implementation of 4th generation mobile and wireless communication systems. This complete reference includes topics ranging from transmission and signal processing techniques to antennas and diversity, ultra wide band, MIMO and reference scenarios for radio network simulation and evaluation. This book will be an ideal source of the latest developments in mobile multimedia broadband technologies for researchers, R&D engineers, graduates and engineers in industry implementing simulation models and conducting measurements. Based on the well known and respected research of the COST 273 project ‘Towards Mobile Broadband Multimedia Networks', whose previous models have been adopted by standardisation bodies such as ITU, ETSI and 3GPP Gives methods, techniques, models and tools for developing 4th generation mobile and wireless communication systems Includes the latest development of key technologies and methods such as MIMO systems, ultra wide-band and OFDM

Download or read book Interference Management in the Downlink of Multiple antenna CDMA Systems written by Md Habibul Islam and published by . This book was released on 2005 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multiuser Linear Precoding for the Downlink of MIMO OFDM Systems written by Hassen Karaa and published by . This book was released on 2007 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multi-tone transmission using orthogonal frequency division multiplexing and multiple antennas has the potential of drastically improving the capacity and the performance of next generation multiuser communications. However, such systems are inherently complex and require a cumbersome computational load. This thesis investigates the efficient extension of linear processing techniques to multi-carrier transmission from a base station to multiple users using multiple antennas at the transmitter and/or the receiver. Previous work in this area focused on the single carrier case. We propose a technique based on interpolation across frequencies to reduce the computational load involved in deriving the linear filters for each frequency. We also consider the problem of user selection to carriers and develop a sum mean squared error based, computationally efficient algorithm to select the best set of users onto each frequency in order to optimize the system's performance.

Download or read book Optimized Transceiver Design for Multiantenna Wireless Communications written by Yan Zhou and published by . This book was released on 2006 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multicarrier DS CDMA Communication Systems Using Smart Antennas written by Bin Hu and published by . This book was released on 2006 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Antenna Arrays for the Downlink of FDD Wideband CDMA Communication Systems written by Antonios Constantinou Koutalos and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transmission Strategies for Multiple Antenna Wireless Ad hoc and Relay Networks written by Rahul Vaze and published by . This book was released on 2009 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless devices have become an integral part of our everyday lives. Cell-phones, PDA's, Wi-Fi enabled laptops, smart homes and appliances, and automated highway systems are some of the examples of wireless devices and networks in common use. More and more applications and functionalities are constantly being added to these devices, and to support these new applications high data rate communication is required between the wireless devices. Achieving high data rates with wireless communication is impeded by severe fluctuations in the received signal strength (called fading) due to mobility, the exponential attenuation of signal power with distance (called path loss), and interference due to simultaneous transmissions by different users at the same time or over same frequency band. Two of the promising techniques to mitigate the effects of fading, path loss, and interference are: using multiple antennas at the transmitter and receiver, and employing extra nodes (called relays) in between the transmitter and its receiver to relay the transmitter's message to its receiver. This dissertation identifies the optimal transmit and receive strategy with multiple antennas that maximizes the transmission capacity of an ad-hoc wireless network. The transmission capacity is defined as the maximum number of transmitter-receiver pairs that can simultaneously communicate under a per transmission quality of service constraint. This dissertation also presents novel relay transmission strategies for multiple antenna equipped relay based communication that achieve near optimal performance, with Shannon capacity and diversity-multiplexing tradeoff (DMT) as the performance metrics. The Shannon capacity is defined as the maximum rate of reliable communication, while the DMT characterizes the maximum diversity gain for a given value of multiplexing gain in a multiple antenna system. DMT is used as the benchmark, since transmission strategies that meet the DMT are guaranteed to leverage both the advantages of multiple antenna systems.

Download or read book Single and Multi Carrier DS CDMA written by Lajos L. Hanzo and published by Wiley-IEEE Press. This book was released on 2003-09-26 with total page 1104 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is dedicated to a range of CDMA and MC-CDMA transmission aspects of systems designed for communicating over fading wireless channels. Currently, a technical in-depth book on this subject, which has a similar detailed exposure of the recent advances in CDMA, M-ary CDMA and MC-CDMA, is unavailable. A further attraction of the joint treatment of these topics is that it allows the reader to view their design trade-offs in a comparative context. Divided into five main parts: Part I: provides a detailed introduction to the subject of CDMA systems designed for employment in various application Part II: deals with the currently hot topic of genetic algorithm assisted multiuser detection Part III: gives a detailed account of new, reduced-complexity M-ary CDMA schemes Part IV: considers a range of novel MC-CDMA schemes which have the potential of supporting numerous design objectives Part V: provides an overview of the 3G wireless system proposals and characterises the expected network capacity gains attained with the aid of adaptive CDMA systems By providing an all-encompassing self-contained treatment this groundbreaking volume will have appeal to researchers, postgraduate students, academics practising research and development engineers working for wireless communications and computer networking companies, as well as senior undergraduate students and technical managers in the field.

Download or read book Multiantenna Wireless Communications Systems written by Sergio Barbarossa and published by Artech House Publishers. This book was released on 2005 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antenna diversity has become of critical importance in today's mobile communications systems and this groundbreaking book offers you new approaches to designing transmission strategies for multi-antenna systems. With these novel and practical design strategies you can develop transmission systems that efficiently use available power and bandwidth. The book shows you how to design multi-antenna transceivers in single antenna systems that can reduce transmission power, while ensuring a specified quality level. In addition, you can design wireless networks that have a prescribed degree and probability of connectivity and fault tolerance.

Download or read book Low Complexity Multiple Antenna Transmission Solutions for Next Generation Wireless Communication Systems written by Muhammad Hanif and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Two of the most prominent techniques to meet the next generation wireless communication system's demands are cognitive radio and massive MIMO systems. Cognitive radio systems improve radio spectrum utilization either by spectrum sharing or by opportunistically utilizing the spectrum of the licensed users. Employing multiple antennas at the transmitter and/or the receiver of the radio can further improve the overall performance of the wireless systems. Massive MIMO systems, on the other hand, improve the spectral and energy efficiencies of currently deployed systems by reaping all the benefits of the multi-antenna systems at a very large scale. The price paid for employing a large number of antennas either at the transmitter or receiver is the high hardware cost. Judicious transmit or receive antenna selection can reduce this cost, while retaining most of the benefits offered by multiple antennas.In my doctoral research, we have presented both upper and lower bounds on the capacity of a general selection diversity system. These novel bounds are simple to compute and can be used in a variety of different fading environments. We have also proposed and analyzed the performance of different antenna selection schemes for both an underlay cognitive radio and a massive MIMO system. Specifically, we have considered both receive and transmit antenna selection in an underlay cognitive radio based on the maximization of secondary link signal-to-interference plus noise ratio. Exact and asymptotic performance analyses of the secondary system with such selections are carried out, and numerical examples are presented to verify the correctness of the analytical results. Several sub-optimal antenna subset selection schemes for both a single-cell and a multi-cell multi-user massive MIMO system are also proposed. Numerical results on the sum rate of the system in different scenarios are presented to verify the superior performance of the proposed schemes over the existing sub-optimal antenna subset selection schemes. Lastly, we have also presented three novel hybrid analog/digital precoding schemes to reduce the hardware and software complexities of a sub-connected massive MIMO system.