Download or read book Performance Analysis of a Multi code Multi carrier CDMA Communication System written by and published by . This book was released on 2004 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new wireless communication system denoted as Multi-Code Multi-Carrier CDMA (MC/MC-CDMA), which is the combination of Multi-Code CDMA and Multi-Carrier CDMA, is analyzed in this thesis. This system can satisfy multi-rate services using multicode schemes and multi-carrier services used for high rate transmission. In addition, the new MC/MC-CDMA system is robust against frequency selective fading, is good for narrowband interference rejection, and has higher spectral efficiency. The system is evaluated in Nakagami slow fading channel model, which can be used to model urban and suburban environments. At the receiver, the system employs three diversity schemes; namely, selection diversity, equal gain combining and maximal ratio combining. The improvements of the diversity schemes are analyzed and compared. Also the system performance is presented and compared with that of other systems such as conventional CDMA system, multi-code CDMA system, and multi-carrier CDMA system. In addition, the performance of the system in the presence of a narrow jammer signal is considered and analyzed. Results indicate that the performance of the MC/MC-CDMA system is superior to that of the conventional CDMA, multi-code CDMA and multi-carrier CDMA systems. It is also shown that the MC/MC-CDMA system is suitable for high data rate and multi-rate services.

Download or read book Design and Performance Analysis of Coded Multi Carrier CDMA Systems written by and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 MULTICODE CDMA FOR HIGH SPEED written by Jun Chen and published by Open Dissertation Press. This book was released on 2017-01-27 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Multicode CDMA for High-speed Mobile Communications" by Jun, Chen, 陳軍, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: ABSTRACT Multicode CDMA for high-speed mobile communications Submitted by CHEN Jun for the degree of Doctor of Philosophy at the University of Hong Kong in April 2002 To meet the challenge of providing high-speed multimedia services over mobile links, new technologies are proposed and studied. Multicode code-division-multiple- access (CDMA) is one of them. However, the introduction of multicode causes several problems. One is the high signal envelope variation. Another is the intra-user multicode interference (MCI) in multipath environment. To cope with these two problems, as well as to achieve better performance, several technologies including complex spreading, interference cancellation, and coherent reception have been developed. This dissertation investigates the integration of these technologies into a Wideband CDMA system. First, we examine the performance of a single code (single data channel) CDMA system with complex spreading scheme and coherent RAKE reception. In particular, the pilot channel estimation error due to multiple access and multipath interference is studied. It is shown that the estimation error severely degrades the system performance and can be effectively suppressed by low pass filters (LPFs). The pilot to data power ratio is studied and it is found that the ratio should be chosen in the range of 0.2 to 0.4 (or -7dB to -4dB) in order to achieve maximum link capacity. Besides that, a discussion on envelope variation demonstrates that complex spread signal has more stable envelope than dual-channel spread signal. iv On top of that, we present the performance analysis of a multicode CDMA system, which utilizes complex spreading, coherent detection and multistage interference cancellation. The optimal cancellation factor for each stage is derived. It is found that (k ) (k-1) the optimal cancellation factor in the k-th stage is approximated by λ to 0.85 for a wide range of signal-to-noise ratios. Finally, a baseband prototype system is developed to illustrate the feasibility of the proposed receiver architecture with multistage MCI cancellation. This dissertation addresses the wideband CDMA technology in the third-generation mobile communication system, the latest development in wireless communication industry. The contribution of this dissertation is twofold. First of all, it develops a complete theoretical analysis for complex-spread signal demodulation and multistage multicode interference cancellation. More than that, it also provides some useful results for practical system design. The optimal pilot power ratio and optimal cancellation factor are useful references for wireless engineers working with Wideband CDMA system. DOI: 10.5353/th_b3014990 Subjects: Mobile communication systems Code division multiple access

Download or read book Performance Analysis of Multicarrier Code Division Mulple i e Multiple Access MC CDMA Systems written by Pravinkumar Patil and published by . This book was released on 2008 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Performance Analysis of Multicarrier CDMA Systems written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research being conducted is designed to yield major improvements in the capabilities of military wireless communications systems. The new system is designed around a physical layer based upon a wideband direct sequence (DS) multicarrier (MC) code division multiple access (CDMA) link. Among other things, an MC signal does not require a contiguous spectrum: this means, for example. that an MC CDMA network can be overlaid upon an existing set of narrowband signals simply by leaving appropriate gaps in the placement of the multiple carriers. Such a characteristic will allow the military to employ the same frequencies as used by various commercial systems, thereby making use of the technology advancements in those frequency bands, and yet not be limited in deployment because of excessive interference from conventional narrowband signals. We have emphasized the effect of estimation errors in determining channel state information for use in optimal receiver design for MC CDMA systems, and have performed analyses of performance. as measured by the average probability of error of the system. We have also included the use of space-time spreading.

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 2013-03-09 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multi-Carrier Spread-Spectrum has been deeply studied and new alternative solutions have been proposed. This book edits the newest contributions and research results in this new field presented at the Third International Workshop on MC-SS & Related Topics, held in Oberpfaffenhofen, Germany.

Download or read book Performance Analysis of Multi code Spread Spectrum CDMA Modulation written by Sami A. S. Khorbotly and published by . This book was released on 2003 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book MULTICARRIER CDMA OVERLAY FOR written by Tat-Tung Wong and published by Open Dissertation Press. This book was released on 2017-01-27 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Multicarrier CDMA Overlay for Ultra-wideband Wireless Communications" by Tat-tung, Wong, 黃達東, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled Multicarrier CDMA Overlay for Ultra-wideband Wireless Communications Submitted by Wong Tat Tung for the degree of Master of Philosophy at The University of Hong Kong in August 2003 Ultra-wideband (UWB) technology is widely considered to offer an innovative solution for future short-range high-speed wireless communications. In this study, the use of multi-carrier direct sequence code division multiple access (MC-DS-CDMA) overlay with both transmitter and receiver filtering is suggested for UWB applications, as an alternative to the conventional carrier-less approach. The main contribution of the study is to provide an analytical framework to illustrate the feasibility of the use of MC-DS- CDMA in UWB wireless communications. A literature review in Chapter 1 provides an overview of UWB technology and explains why MC-DS-CDMA is considered to be a feasible candidate for UWB communications. In Chapter 2, the factors of characterized large number multiple propagation paths and the existence of strong narrowband systems are taken into account for the construction of system model. Numerical expressions for performance evaluation are formulated and the system analysis is conducted with the assumption of random spreading code and Gaussian approximation. The performances of various receiving strategies are compared extensively. Results in Chapter 3 show that the proposed MC- DS-CDMA UWB system is capable of using spectrum already allocated to established services without causing noticeable interference to the existing users, and that pre- combining a minimum mean square error receiver with selective-maximal combining provides much better performance than a receiver made up of notch filter in cascade with code matched correlator or a code matched correlator receiver. A discussion of the significance of these results and conclusions are provided in Chapter 4 and Chapter 5 respectively. (247 Words) DOI: 10.5353/th_b2949119 Subjects: Code division multiple access Ultra-wideband devices Wireless communication systems

Download or read book Design and Analysis of Multicarrier Multicode Wavelet Packets Based CDMA Communication Systems with Multiuser Detection written by Maryam Akho-Zahieh and published by . This book was released on 2006 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: "As the demand for transmitting variable and high data rates rises, the need to develop more efficient wireless communication systems increases. In this dissertation, a new Wavelet Packets based Multicarrier Multicode Code Division Multiple Access (WP-MC/MCD-CDMA) system, which combines the properties of wavelet packets with the concept of MC, MCD and CDMA, is proposed and analyzed. Another new wavelet packets based system, denoted as Wavelet Packets Multicarrier Multiuser Code Division Multiple Access (WP-MC/MU-CDMA) system, which combines the properties of wavelet packets with the concept of MC and CDMA, is proposed and analyzed. The WP-MC/MCD-CDMA can be used for multirate services using multicode schemes. In WP-MC/MU-CDMA system, a decorrelating suboptimum detector is used in the detection process. This will suppress the multiple access interference, support a higher number of users and relaxes the power control requirements. In our systems, wavelet packets functions are used as subcarrier instead of a sinusoidal function. Thus, the proposed systems have high immunity against interferences caused by multipath and multicarriers. The systems are evaluated in Nakagami slow fading channel, and their performance are investigated in terms of signal-to-noise plus interference ratio, bit error rate and outage probability. Three diversity combiners, namely selective diversity, equal gain combining and maximal ratio combining are used at the receiver to improve the system performance. Results show that the new proposed systems are viable for future generation wireless systems."--abstract.

Download or read book Multi Carrier and Spread Spectrum Systems written by K. Fazel and published by John Wiley & Sons. This book was released on 2004-02-06 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frequency spectrum is a limited and valuable resource for wireless communications. A good example can be observed among network operators in Europe for the prices to pay for UMTS-frequency bands. Therefore, the first goal when designing future wireless communication systems (e.g. 4G - fourth generation) has to be the increase in spectral efficiency. The development in digital communications in the past years has enabled efficient modulation and coding techniques for robust and spectral efficient data, speech, audio and video transmission. These are the multi-carrier modulation (e.g. OFDM) and the spread spectrum technique (e.g. DS-CDMA), where OFDM was chosen for broadcast applications (DVB, DAB) as well as for broadband wireless indoor standards (ETSI HIPERLAN-II, IEEE-802.11) and the DS-CDMA was selected in mobile communications (IS-95, third generation mobile radio systems world wide, UMTS/IMT 2000). Since 1993 various combinations of multi-carrier (MC) modulation and the spread spectrum (SS) technique have been introduced and the field of MC-SS communications has become an independent and important research topic with increasing activities. New application fields have been proposed such as high rate cellular mobile, high rate wireless indoor and LMDS. It has been shown that MC-SS offers the high spectral efficiency, robustness and flexibility that is required for the next generation systems. Meanwhile, different alternative hybrid schemes such as OFDM/OFDMA, MC-TDMA, etc. have been deeply analysed and adopted in different international standards (ETSI-BRAN, IEEE-802 & MMAC). Multi-Carrier & Spread-Spectrum: Analysis of Hybrid Air Interfaces draws together all of the above mentioned hybrid schemes therefore providing a greatly needed resource for system engineers, telecommunication designers and researchers in order to enable them to develop, build and deploy several schemes based on MC-transmission for the next generation systems (which will be an integration of broadband multimedia services covering both 4G mobile and fixed wireless systems). * Offers a complete treatment of multi-carrier, spread-spectrum (SS) and time division multiplexing (TDM) techniques * Provides an in-depth insight into hybrid multiple access techniques based on multi-carrier (MC) transmission * Presents numerous hybrid multiple access and air interface architectures including OFDM/CDMA, MC-CDMA, MC-DS-CDMA and MT-CDMA * Covers new techniques such as space-time coding and software radio Telecommunications engineers, hardware & software system designers and researchers as well as students, lecturers and technicians will all find this an invaluable addition to their bookshelf.

Download or read book Multi Carrier Spread Spectrum written by Khaled Fazel and published by Springer Science & Business Media. This book was released on 2006-02-23 with total page 528 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. The aim of Multi-Carrier Spread-Spectrum is to edit the ensemble of the newest contributions and research results in this new 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 OFDM and MC CDMA for Broadband Multi User Communications WLANs and Broadcasting written by Lajos Hanzo and published by John Wiley & Sons. This book was released on 2005-01-28 with total page 1014 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal frequency-division multiplexing (OFDM) is a method of digital modulation in which a signal is split into several narrowband channels at different frequencies. CDMA is a form of multiplexing, which allows numerous signals to occupy a single transmission channel, optimising the use of available bandwidth. Multiplexing is sending multiple signals or streams of information on a carrier at the same time in the form of a single, complex signal and then recovering the separate signals at the receiving end. Multi-Carrier (MC) CDMA is a combined technique of Direct Sequence (DS) CDMA (Code Division Multiple Access) and OFDM techniques. It applies spreading sequences in the frequency domain. Wireless communications has witnessed a tremendous growth during the past decade and further spectacular enabling technology advances are expected in an effort to render ubiquitous wireless connectivity a reality. This technical in-depth book is unique in its detailed exposure of OFDM, MIMO-OFDM and MC-CDMA. 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 three main parts: Part I provides a detailed exposure of OFDM designed for employment in various applications Part II is another design alternative applicable in the context of OFDM systems where the channel quality fluctuations observed are averaged out with the aid of frequency-domain spreading codes, which leads to the concept of MC-CDMA Part III discusses how to employ multiple antennas at the base station for the sake of supporting multiple users in the uplink Portrays the entire body of knowledge currently available on OFDM Provides the first complete treatment of OFDM, MIMO(Multiple Input Multiple Output)-OFDM and MC-CDMA Considers the benefits of channel coding and space time coding in the context of various application examples and features numerous complete system design examples Converts the lessons of Shannon’s information theory into design principles applicable to practical wireless systems Combines the benefits of a textbook with a research monograph where the depth of discussions progressively increase throughout the book This all-encompassing self-contained treatment will appeal to researchers, postgraduate students and academics, practising research and development engineers working for wireless communications and computer networking companies and senior undergraduate students and technical managers.

Download or read book Multi Carrier Spread Spectrum 2007 written by Simon Plass and published by Springer Science & Business Media. This book was released on 2007-06-14 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the proceedings of the 6th International Workshop on Multi-Carrier Spread Spectrum (MC-SS 2007), 7-9 May 2007, held in Herrsching, Germany. The book aims to edit the ensemble of the newest contributions and research results in this new field. The book presents comprehensive state-of-the-art articles about multi-carrier spread spectrum techniques, and discusses multi-carrier spread spectrum techniques.

Download or read book OFDM and MC CDMA written by Lajos Hanzo and published by John Wiley & Sons. This book was released on 2007-01-11 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless communications has witnessed a tremendous growth during the past decade and further spectacular enabling technology advances are expected in an effort to render ubiquitous wireless connectivity a reality. Currently, a technical in-depth book on this subject is unavailable, which has a similar detailed exposure of OFDM, MIMO-OFDM and MC-CDMA. 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 three main parts: Part I provides a detailed exposure of OFDM designed for employment in various applications Part II is another design alternative applicable in the context of OFDM systems where the channel quality fluctuations observed are averaged out with the aid of frequency-domain spreading codes, which leads to the concept of MC-CDMA Part III discusses how to employ multiple antennas at the base station for the sake of supporting multiple users in the uplink By providing an all-encompassing self-contained treatment this volume will appeal to a wide readership, as it is both an easy-reading textbook and a high-level research monograph.

Download or read book Multicarrier Communications written by Lie-Liang Yang and published by John Wiley & Sons. This book was released on 2009-01-21 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: Benefiting from both time-domain and frequency-domain signal processing techniques, multicarrier systems have the potential for achieving high spectral-efficiency, high-flexibility and low-complexity wireless communications. Multicarrier techniques therefore constitute the promising techniques for implementation of future generations of wideband, broadband and ultra-wideband systems. Multicarrier Communications offers comprehensive and in-depth evaluation of numerous topics in the area, covering the fundamental principles of spread-spectrum and multicarrier CDMA as well as more advanced topics such as multiuser detection (MUD), multiuser transmitter preprocessing (MUTP), MIMO and space-time processing. It examines OFDM and various multicarrier CDMA within an unified framework and provides analytical approaches and formulas for error-performance evaluation of numerous multicarrier systems. Examines MUD and MUTP in parallel to illustrate the strong duality between receiver optimization and transmitter optimization Comprehensively establishes the theory of noncoherent MUD and noncoherent interference suppression Details the body of knowledge on MIMO theory and space-time multicarrier communications Contains tables, diagrams and figures to illustrate the performance results. Practicing electrical engineers and researchers in wireless communications will find Multicarrier Communications an invaluable guide. It will also be of interest to senior undergraduate and graduate students on wireless communications courses.