Download or read book Peak to average Power Ratio PAPR Reduction Using OFDM Null Subcarriers written by Bo Wang and published by . This book was released on 2011 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selective Mapping technique for PAPR reduction in LTE OFDM Systems written by Neelam Dewangan and published by GRIN Verlag. This book was released on 2012-11-22 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master's Thesis from the year 2012 in the subject Engineering - Communication Technology, grade: none, , course: M.Tech, language: English, abstract: As a promising technique, OFDM has been widely used in emerging broadband communication systems, such as digital audio broadcasting (DAB), high-definition television (HDTV), wireless local area network (IEEE 802.11a and HIPERLAN/2). However, as the OFDM signals are the sum of signals with random amplitude and phase, they are likely to have large PAPR that requires a linear high-power- amplifier (HPA) with an extremely high dynamic range, which is expensive and inefficient. Furthermore, any amplifier nonlinearity causes intermodulation products resulting in unwanted out-of-band power. A number of approaches have been proposed to deal with the PAPR problem, including clipping, clipping-and-filtering (CF), coding, companding transform, active constellation extension (ACE), selected mapping (SLM), partial transmit sequence (PTS), and so on. This thesis proposes an improvement in Selected Mapping technique and Simulation results are compared to existing techniques namely Exponential Companding Transform, Repeated Clipping and Filtering and Adaptive Active Constellation Extension. The improvements which are proposed in classical Selective Mapping technique satisfies the PAPR Reduction criteria with reducing the computational complexity. Also this new scheme has an important advantage of avoiding the extra bits along with the transmitted OFDM signal .This scheme can also be applied to the multiple transmitting antenna cases.
Download or read book Peak to Average Power Ratio Reduction in OFDM Systems written by Anusha Chacko and published by LAP Lambert Academic Publishing. This book was released on 2015-04-17 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) is a promising technology in wireless communication. High Peak-to-Average Power Ratio (PAPR) is one of the challenging issues of OFDM systems. High PAPR forces the High Power Amplifier (HPA) to operate in its linear region with wide dynamic range, where the power efficiency is very poor. This book gives an overview of different PAPR reduction techniques. And deals in detail with the efficient use of Selected Mapping (SLM) and Partial Transmit Sequence (PTS)technique to reduce high PAPR in OFDM systems.
Download or read book PAPR Reduction Techniques Analysis and Applications written by Dr. RAJKUMAR L. BIRADAR and published by Archers & Elevators Publishing House. This book was released on with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PAPR Reduction for OFDM written by William Liu and published by . This book was released on 2013-07-02 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: A major drawback of OFDM systems is its high peak-to-average power ratio (PAPR) of the transmit signal. In this book, we describe the design, working principle, advantage and disadvantage of OFDM. A comprehensive analysis of different PAPR reduction methods is presented. The DFT-Spread method, which is the most effective and efficient PAPR reduction technique, is identified. A very detailed theoretical analysis to the DFT-Spread method is provided with regard to the PAPR, both for single user case and multi-user case, with localized subcarrier mapping and distributed subcarrier mapping. For the multi-user case, the analysis is novel and has not been seen anywhere in any publications. A theoretical relationship is derived for the DFT-Spread method with distributed subcarrier mapping, which reveals the PAPR as a function of the modulation order and the number of users. In addition, a novel signal scrambling method is proposed to reduce the PAPR by using space-time block codes. Detailed simulation investigations and analyses are carried out to evaluate the PAPR performance of the DFT-Spread method and the proposed space-time block code signal scrambling method. Simulation investigation is also carried out to investigate the impact of DFT-Spread on the receiving performance.
Download or read book OFDM Systems and PAPR Reduction Techniques in OFDM Systems written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Communication is one of the important aspects of life. With the advancement in age and its growing demands, there has been rapid growth in the field of communications. Signals, which were initially sent in the analog domain, are being sent more and more in the digital domain these days. For better transmission, even single - carrier waves are being replaced by multi - carriers. Multi - carrier systems like CDMA and OFDM are now - a - days being implemented commonly. In the OFDM system, orthogonally placed sub - carriers are used to carry the data from the transmitter end to the receiver end. Presence of guard band in this system deals with the problem of ISI and noise is minimized by larger number of sub - carriers. But the large Peak - to - Average Power Ratio of these signal have some undesirable effects on the system. In this thesis we have focused on learning the basics of an OFDM System and have undertaken various methods to reduce the PAPR in the system so that this system can be used more commonly and effectively.
Download or read book PAPR Reduction Techniques for OFDM Signals written by Bathula Siva Kumar Reddy and published by LAP Lambert Academic Publishing. This book was released on 2015-09-23 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM), a multicarrier modulation technique, widely used for many of the latest wireless standards such as Wi-Fi, LTE / LTE-A, DAB, DVB, WiMAX and so on. However, its high peak-to-average power ratio (PAPR) for a large number of subcarriers which may drive the amplifier into non-linear region that radiates signals out of band, making it unobtrusive for practical applications. In this book, the comprehensive research and comparison are put forward for a variety of currently promising PAPR reduction methods on the basis of extensive reading and studying of associated papers and literature in this research area. The book caters to the needs of research fraternity and students in the field of wireless communication. The requirement for the readers of this book is to be familiar with the basics of OFDM system, however, R & D engineers from industry community working under wireless communication group can also benefit from this book as a supplementary reference.
Download or read book PAPR and ICI Reduction Techniques for OFDM Based Satellite Communication Systems written by Emad Yacoub Qeryaqos Al-Dalakta and published by . This book was released on 2012 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Papr Reduction in Ofdm System Using Pulse Shaping Technique written by Prakash Shahi and published by LAP Lambert Academic Publishing. This book was released on 2011-02 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) techniques allow the transmission of high data rates over broadband radio channels subject to multipath fading without the need for powerful channel equalization. However, they are very sensitive to nonlinear effects owing to high peak-to-average power ratio (PAPR) owned by their transmitted signals. This thesis proposes an efficient technique for reducing the PAPR of OFDM signals.The proposed technique is data-independent and, thus, does not require new processing and optimization for each transmitted OFDM block. The reduction in PAPR of the OFDM signal is obtained through a proper selection of a pulse shaping scheme that distributes the power of each modulated symbol over the OFDM block such that the average power of OFDM signal will not be far from individual symbol power. It is shown, through computer simulations, that the PAPR of pulse shaped OFDM signals approaches that of single-carrier signals.The pulse shaping schemes also take advantage of the frequency variations of the communication channel and can provide considerable performance gain in multipath fading channels
Download or read book A detailed Study of 4G in Wireless Communication Looking insight in issues in OFDM written by Neelam Dewangan and published by Anchor Academic Publishing (aap_verlag). This book was released on 2014-02-01 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a promising technique, OFDM has been widely used in emerging broadband communication systems, such as digital audio broadcasting (DAB), high-definition television (HDTV), and wireless local area network (IEEE 802.11a and HIPERLAN/2). However, as the OFDM signals are the sum of signals with random amplitude and phase, they are likely to have large PAPR that require a linear high-power- amplifier (HPA) with an extremely high dynamic range which is expensive and inefficient. Furthermore, any amplifier nonlinearity causes intermodulation products resulting in unwanted out-of-band power. A number of approaches have been proposed to deal with the PAPR problem, including amongst others, clipping, clipping-and-filtering (CF), coding, companding transform, active constellation extension (ACE), selected mapping (SLM), and partial transmit sequence (PTS). This book proposes an improvement in the selected mapping technique. The resulting scheme can also be applied to the multiple transmitting antenna cases. Further, it compares the simulation results to the existing techniques namely exponential companding transform, repeated clipping and filtering, and adaptive active constellation extension.
Download or read book PAPR Reduction in OFDM Systems Using Coded Standard Arrays written by Dijin Chen and published by . This book was released on 2004 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Communication and Networking written by Tai-hoon Kim and published by Springer Science & Business Media. This book was released on 2011-11-29 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: The two volume set, CCIS 265 and CCIS 266, constitutes the refereed proceedings of the International Conference, FGCN 2011, held as Part of the Future Generation Information Technology Conference, FGIT 2011, Jeju Island, Korea, in December 2011. The papers presented were carefully reviewed and selected from numerous submissions and focus on the various aspects of future generation communication and networking.
Download or read book New Tone Reservation PAPR Reduction Techniques for Multicarrier Systems written by Ralph Mounzer and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) has been adopted by many telecommunication and broadcasting systems for its robustness, high transmission rates, mobility and bandwidth efficiency. However, OFDM signals are characterized by high power fluctuations, measured by the Peak to Average Power Ratio (PAPR), which cause distortions at the output of the non-linear High Power Amplifier (HPA) and prevent the radio frequency designer to feed the signal at the optimal point of the HPA specifications in order to reduce the energy consumption. The second generation of Digital Video Broadcasting (DVB-T2) adopted two PAPR reduction techniques, one of them is Tone Reservation (TR). TR creates a Kernel from a reserved set of subcarriers. The kernel is then iteratively added to the OFDM signal in such a way to reduce its peaks thus reducing its PAPR. In the first part of the thesis, different algorithms offering better performances compared to the DVB-T2 TR solution are proposed. A first group of solutions introduces changes and enhancements to the TR algorithm adopted in DVB-T2 TR but keeps the same kernel definition. This group includes: the Partial Oversampling and Fractional Shifted Kernels (POFSK) technique which is based on a partial oversampling of the signal, the Dynamic Threshold (DT) technique which allows better algorithm convergence by dynamically computing the PAPR reduction threshold for every OFDM symbol, and the Enhanced Peak Selection (EPS) technique which provides additional PAPR reduction by choosing the appropriate signal peaks to reduce and the peaks to skip. The second group of solutions includes the Individual Carrier Multiple Peaks (ICMP) technique which is based on a special kernel definition that changes from one algorithm iteration to another and uses a different phase calculation approach that allows the reduction of multiple peaks at a time. GICMP is an optimized version of ICMP that allows the parallelization of iterations in such a way to reduce the processing delay and the number of algorithm iterations. The simulation results and real hardware platform measurements of the proposed algorithms showed that, compared to the DVB-T2 TR version, the GICMP algorithm allows a Modulation Error Rate - MER gain of up to 2.5 dB or a 10 % reduction in HPA consumed energy with the same performances.
Download or read book PAPR Reduction Channel Estimation Techniques For MIMO OFDMA Systems written by D. M. Motiur Rahaman and published by . This book was released on 2014-08-09 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cognitive Radio Communications and Networks written by Alexander M. Wyglinski and published by Academic Press. This book was released on 2009-11-13 with total page 737 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cognitive Radio Communications and Networks gives comprehensive and balanced coverage of the principles of cognitive radio communications, cognitive networks, and details of their implementation, including the latest developments in the standards and spectrum policy. Case studies, end-of-chapter questions, and descriptions of various platforms and test beds, together with sample code, give hands-on knowledge of how cognitive radio systems can be implemented in practice. Extensive treatment is given to several standards, including IEEE 802.22 for TV White Spaces and IEEE SCC41 Written by leading people in the field, both at universities and major industrial research laboratories, this tutorial text gives communications engineers, R&D engineers, researchers, undergraduate and post graduate students a complete reference on the application of wireless communications and network theory for the design and implementation of cognitive radio systems and networks Each chapter is written by internationally renowned experts, giving complete and balanced treatment of the fundamentals of both cognitive radio communications and cognitive networks, together with implementation details Extensive treatment of the latest standards and spectrum policy developments enables the development of compliant cognitive systems Strong practical orientation – through case studies and descriptions of cognitive radio platforms and testbeds – shows how real world cognitive radio systems and network architectures have been built Alexander M. Wyglinski is an Assistant Professor of Electrical and Computer Engineering at Worcester Polytechnic Institute (WPI), Director of the WPI Limerick Project Center, and Director of the Wireless Innovation Laboratory (WI Lab) Each chapter is written by internationally renowned experts, giving complete and balanced treatment of the fundamentals of both cognitive radio communications and cognitive networks, together with implementation details Extensive treatment of the latest standards and spectrum policy developments enables the development of compliant cognitive systems Strong practical orientation – through case studies and descriptions of cognitive radio platforms and testbeds – shows how "real world" cognitive radio systems and network architectures have been built
Download or read book Peak to Average Power Reduction for Multi antenna of OFDM Systems written by Madhan Jaganthan and published by . This book was released on 2008 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Rate Techniques for PAPR Reduction in OFDM Systems written by Sudarshan M. Kannappan and published by . This book was released on 2012 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless communication has evolved so much today that it has greatly been integrated into everyone's life. From listening to music using Bluetooth headset, accessing information on the web on the move using WiFi or 3G to calling our loved ones who are on the other side of the globe and locating our position when lost, can be done using a plethora of wireless devices available today. This thesis addresses the problem of high peak-to-average power ratio (PAPR) found in orthogonal frequency division multiplexing (OFDM) modems. The reason for high PAPR in OFDM is the constructive addition of sinusoidal signals at different frequencies. High PAPR increases the dynamic range of power amplifier operation, thereby resulting in increased cost and chip area. This thesis proposes several high rate techniques to reduce PAPR. One technique extends the efficiency of the well known complementary code keying (CCK) OFDM. The second technique eliminates high PAPR by removing the periodicity which may exist between the bits fed to the OFDM transmitter. This rate-12/16 technique is compared to other techniques such as traditional OFDM and carrier-interferometry (CI) OFDM. Further, this thesis integrates the proposed rate-12/16 technique and CCK to obtain an improved rate-12/16 technique, which brings the PAPR value down to a new low. Bit error rates (BER) are obtained for each coding technique for comparison. The proposed rate-12/16 technique achieves good BER performance due to the coding gain it provides. The improved rate-12/16 outperformed all the techniques discussed in terms of PAPR.
