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 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 2013-08 with total page 97 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 Techniques in Lte Ofdm Networks written by Neelam Dewangan and published by LAP Lambert Academic Publishing. This book was released on 2012-05 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a promising technique, OFDM has been widely used in many new and 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 and also increases complexity of DAC-ADC convertors.This work describes some of the PAPR Reduction Techniques and comparison among them.
Download or read book An Improved Selected Mapping Scheme for PAPR Reduction in OFDM Systems written by and published by . This book was released on 2006 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) is a spectrally efficient multicarrier modulation technique for high speed data transmission over multipath fading channels. High Peak-to-Average Power Ratio (PAPR), which leads to power inefficiency in the RF portion of the transmitter, is a major drawback of OFDM. Lots of PAPR reduction techniques are proposed in literatures in last two decades. For instance, amplitude clipping, companding, coding, partial transmit sequence, selected mapping (SLM), interleaving, etc. Among these techniques, SLM is a promising distortionless scheme to reduce PAPR. The major drawbacks of SLM are high complexity and the need to transmit side information. This thesis introduced an improved SLM scheme with a PAPR threshold. Mathematic expressions of Complementary Cumulative Distribution Function (CCDF) and expected number of mappings are derived and tested by computer simulations. The improved scheme has much lower computational complexity but keeps the same PAPR reduction performance comparing with traditional SLM technique.
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 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.
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 Single Carrier FDMA written by Hyung G. Myung and published by John Wiley & Sons. This book was released on 2008-11-20 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single Carrier Frequency Division Multiple Access (SC-FDMA) is a novel method of radio transmission under consideration for deployment in future cellular systems; specifically, in 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) systems. SC-FDMA has drawn great attention from the communications industry as an attractive alternative to Orthogonal Frequency Division Multiple Access (OFDMA). Introduction to Single Carrier FDMA places SC-FDMA in the wider context of wireless communications, providing the reader with an in-depth tutorial on SC-FDMA technology. The book introduces the reader to this new multiple access technique that utilizes single carrier modulation along with orthogonal frequency multiplexing and frequency domain equalization, plus its applications in communications settings. It considers the similarities with and differences from orthogonal frequency division modulation, multiplexing, and multiple access used extensively in cellular, broadcasting, and digital subscriber loop applications. Particular reference is made to the peak power characteristics of an SC-FDMA signal as an added advantage over OFDMA. Provides an extensive overview of the principles of SC-FDMA and its relation to other transmission techniques. Explains how the details of a specific implementation influence the tradeoffs among various figures of merit. Describes in detail the configuration of the SC-FDMA uplink transmission scheme published by 3GPP. Features link level simulation of an uplink SC-FDMA system using MATLAB. This is an essential text for industry engineers who are researching and developing 3GPP LTE systems. It is suitable for engineers designing wireless network equipment, handsets, data cards, modules, chipsets, and test equipment as well as those involved in designing LTE infrastructure. It would also be of interest to academics, graduate students, and industry researchers involved in advanced wireless communications, as well as business analysts who follow the cellular market.
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 OFDM Systems for Wireless Communications written by Adarsh Narasimhamurthy and published by Springer Nature. This book was released on 2022-06-01 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) systems are widely used in the standards for digital audio/video broadcasting, WiFi and WiMax. Being a frequency-domain approach to communications, OFDM has important advantages in dealing with the frequency-selective nature of high data rate wireless communication channels. As the needs for operating with higher data rates become more pressing, OFDM systems have emerged as an effective physical-layer solution. This short monograph is intended as a tutorial which highlights the deleterious aspects of the wireless channel and presents why OFDM is a good choice as a modulation that can transmit at high data rates. The system-level approach we shall pursue will also point out the disadvantages of OFDM systems especially in the context of peak to average ratio, and carrier frequency synchronization. Finally, simulation of OFDM systems will be given due prominence. Simple MATLAB programs are provided for bit error rate simulation using a discrete-time OFDM representation. Software is also provided to simulate the effects of inter-block-interference, inter-carrier-interference and signal clipping on the error rate performance. Different components of the OFDM system are described, and detailed implementation notes are provided for the programs. The program can be downloaded here. Table of Contents: Introduction / Modeling Wireless Channels / Baseband OFDM System / Carrier Frequency Offset / Peak to Average Power Ratio / Simulation of the Performance of OFDM Systems / Conclusions
Download or read book MIMO OFDM Wireless Communications with MATLAB written by Yong Soo Cho and published by John Wiley & Sons. This book was released on 2010-08-20 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: MIMO-OFDM is a key technology for next-generation cellular communications (3GPP-LTE, Mobile WiMAX, IMT-Advanced) as well as wireless LAN (IEEE 802.11a, IEEE 802.11n), wireless PAN (MB-OFDM), and broadcasting (DAB, DVB, DMB). In MIMO-OFDM Wireless Communications with MATLAB®, the authors provide a comprehensive introduction to the theory and practice of wireless channel modeling, OFDM, and MIMO, using MATLAB® programs to simulate the various techniques on MIMO-OFDM systems. One of the only books in the area dedicated to explaining simulation aspects Covers implementation to help cement the key concepts Uses materials that have been classroom-tested in numerous universities Provides the analytic solutions and practical examples with downloadable MATLAB® codes Simulation examples based on actual industry and research projects Presentation slides with key equations and figures for instructor use MIMO-OFDM Wireless Communications with MATLAB® is a key text for graduate students in wireless communications. Professionals and technicians in wireless communication fields, graduate students in signal processing, as well as senior undergraduates majoring in wireless communications will find this book a practical introduction to the MIMO-OFDM techniques. Instructor materials and MATLAB® code examples available for download at www.wiley.com/go/chomimo
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 Proceedings of the 12th National Technical Seminar on Unmanned System Technology 2020 written by Khalid Isa and published by Springer Nature. This book was released on 2021-09-24 with total page 1155 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises the proceedings of the 12th National Technical Symposium on Unmanned System Technology 2020 (NUSYS’20) held on October 27–28, 2020. It covers a number of topics, including intelligent robotics, novel sensor technology, control algorithms, acoustics signal processing, imaging techniques, biomimetic robots, green energy sources, and underwater communication backbones and protocols, and it appeals to researchers developing marine technology solutions and policy-makers interested in technologies to facilitate the exploration of coastal and oceanic regions.
Download or read book International Conference on Intelligent Data Communication Technologies and Internet of Things ICICI 2018 written by Jude Hemanth and published by Springer. This book was released on 2018-12-20 with total page 1590 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses data communication and computer networking, communication technologies and the applications of IoT (Internet of Things), big data, cloud computing and healthcare informatics. It explores, examines and critiques intelligent data communications and presents inventive methodologies in communication technologies and IoT. Aimed at researchers and academicians who need to understand the importance of data communication and advanced technologies in IoT, it offers different perspectives to help readers increase their knowledge and motivates them to conduct research in the area, highlighting various innovative ideas for future research.
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 LTE for 4G Mobile Broadband written by Farooq Khan and published by Cambridge University Press. This book was released on 2009-03-26 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understand the new technologies of the LTE standard and their impact on system performance improvements with this practical guide.
