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Peak To Average Power Ratio Papr Reduction In Orthogonal Frequency Division Multiplexing Ofdm Communication Systems
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Book Synopsis Peak to Average Power Ratio (PAPR) Reduction in Orthogonal Frequency Division Multiplexing (OFDM) Communication Systems by : Xuefu Zhou
Download or read book Peak to Average Power Ratio (PAPR) Reduction in Orthogonal Frequency Division Multiplexing (OFDM) Communication Systems written by Xuefu Zhou and published by . This book was released on 2002 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Peak-to-Average Power Ratio Reduction in Ofdm Systems by : Mohammed El-Absi
Download or read book Peak-to-Average Power Ratio Reduction in Ofdm Systems written by Mohammed El-Absi and published by LAP Lambert Academic Publishing. This book was released on 2011-02 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal frequency division multiplexing (OFDM) technology promises to be a key technique for achieving the high data capacity and spectral efficiency requirements for wireless communication systems of the near future. However, OFDM poses high peak-to-average power ratio (PAPR) problem, as a consequence of independently modulated carriers, that causes degradation on the error performance of the system, low efficiency of the power amplifier, and increases the complexities of the system. Reducing the PAPR can be regarded as an important issue to realize efficient and affordable communication services. This study proposes efficient PAPR reduction methods for OFDM signals by decreasing the possibility of peaks of the subcarriers signals to occur at the same time. The achieved results confirm that the proposed methods are capable of reducing the PAPR significantly and, therefore, of improving error performance of the system. The proposed methods were applied to multicarrier code division multiple access (MC-CDMA.
Book Synopsis Orthogonal Frequency Division Multiplexing for Wireless Communications by : Ye Geoffrey Li
Download or read book Orthogonal Frequency Division Multiplexing for Wireless Communications written by Ye Geoffrey Li and published by Springer Science & Business Media. This book was released on 2006-05-31 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing for Wireless Communications is an edited volume with contributions by leading authorities in the subject of OFDM. Its coverage consists of principles, important wireless topics (e.g. Synchronization, channel estimation, etc.) and techniques. Included is information for advancing wireless communication in a multipath environment with an emphasis on implementation of OFDM in base stations. Orthogonal Frequency Division Multiplexing for Wireless Communications provides a comprehensive introduction of the theory and practice of OFDM. To facilitate the readers, extensive subject indices and references are given at the end of the book. Even though each chapter is written by different experts, symbols and notations in all chapters of the book are consistent.
Book Synopsis Peak to Average Power Ratio Reduction Using the Clipping Technique in Orthogonal Frequency Division Multiplexing System by : Wan Hafiza Wan Hassan
Download or read book Peak to Average Power Ratio Reduction Using the Clipping Technique in Orthogonal Frequency Division Multiplexing System written by Wan Hafiza Wan Hassan and published by . This book was released on 2006 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: The demand for high-speed mobile wireless communications is rapidly growing. The orthogonal frequency division multiplexing (OFDM) technology promises to be a key technique for achieving the high data capacity and spectral efficiency requirements for wireless communication systems of the near future. With its natural resistance to multipath fading and its capability to support extremely high data rates, OFDM is a major candidate for a fourth generation system. Despite many advantages of OFDM, it has two major drawbacks which are high peak to average power ratio (PAPR) and sychronization problem. A high PAPR causes saturation in power amplifiers, leading to intermodulation products among the sub carriers and disturbing out of band energy. Therefore, it is desirable to reduce the PAPR by means of PAPR reduction schemes. Clipping has been identified as the simplest yet effective technique of PAPR reduction. However, we have found out that clipping has resulted in the degradation of BER and enhanced the growth of out of band radiation leading to the degradation of the OFDM overall performance. As a solution, we have proposed an enhanced OFDM system with the objectives of reducing the high PAPR values while minimizing the effects of clipping. The convolutional coding scheme incorporated into the proposed system as a forward error control (FEC) scheme to improve the performance of BER in OFDM system. Besides, oversamples IFFT and digital filtering techniques are introduced into the system to minize the out of band radiation (OOBR). In this thesis, we have shown that the proposed system has significantly enhanced the BER performance and minimized the OOBR. However, there are a few trade-off which affected the overall performance. Hence, we have identified the optimum designed parameters which have resulted in a maximum PAPR reduction and OOBR suppression capability of 9 dB and 52 dB respectively at the cut-off BER of 10-4. In comparison to the existing proposed systems, our proposed system can be considered as one of the optimum system as it offers good PAPR reduction as well as OOBR suppression and comparable BER performance at the lowest value of SNR.
Author :Natarajan Meghanathan Publisher :Springer Science & Business Media ISBN 13 :3642315135 Total Pages :800 pages Book Rating :4.6/5 (423 download)
Book Synopsis Advances in Computing and Information Technology by : Natarajan Meghanathan
Download or read book Advances in Computing and Information Technology written by Natarajan Meghanathan and published by Springer Science & Business Media. This book was released on 2012-06-30 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt: The international conference on Advances in Computing and Information technology (ACITY 2012) provides an excellent international forum for both academics and professionals for sharing knowledge and results in theory, methodology and applications of Computer Science and Information Technology. The Second International Conference on Advances in Computing and Information technology (ACITY 2012), held in Chennai, India, during July 13-15, 2012, covered a number of topics in all major fields of Computer Science and Information Technology including: networking and communications, network security and applications, web and internet computing, ubiquitous computing, algorithms, bioinformatics, digital image processing and pattern recognition, artificial intelligence, soft computing and applications. Upon a strength review process, a number of high-quality, presenting not only innovative ideas but also a founded evaluation and a strong argumentation of the same, were selected and collected in the present proceedings, that is composed of three different volumes.
Book Synopsis Peak to Average Power Ration Reduction and Bit Error Rate Improvement in Wireless Orthogonal Frequency Division Multiplexing Communication Systems by : Wisam Fahmi Al-Azzo
Download or read book Peak to Average Power Ration Reduction and Bit Error Rate Improvement in Wireless Orthogonal Frequency Division Multiplexing Communication Systems written by Wisam Fahmi Al-Azzo and published by . This book was released on 2009 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal frequency division multiplexing (OFDM) offers high data rate transmission with high spectral efficiency, immunity to multipath fading, and simple implementation using fast Fourier transform (FFT). OFDM is readily implemented by present day processors in many high speed networks. However, one of the major drawbacks of OFDM systems is the high peak-to-average power ratio (PAPR); this can result in poor power efficiency, degradation in bit-error-rate (BER) performance, and spectral spreading. The effective PAPR reduction of OFDM signals by simple processing has been challenge for the limited power and processing capability of portable OFDM applications. This thesis investigates the problem of high PAPR in OFDM systems and presents many simple implementation PAPR reduction techniques, and one error-resilient technique. The first part of this thesis presents two time-domain PAPR reduction techniques, viz, square-rooting the envelope of the OFDM output signals, and the smoothing technique. The square-rooting process changes the statistical distribution of the OFDM output signals from Rayleigh to Gaussian-like distribution and reduces the differences between the value of peak and average power, which consequently reduces the PAPR significantly. About 6 dB reduction in PAPR is achieved with moderate degradation in BER performance. For the smoothing process, which is derived from the image enhancement technique, the smoothing applied on the OFDM signals mitigates the PAPR due to its averaging effect. Up to 2.5 dB reduction is achieved by smoothing. Two new probabilistic based non-iterative frequency-domain PAPR reduction techniques are introduced in the second part of the thesis. These techniques reduce PAPR by changing the statistical distribution of the OFDM modulated symbols from uniform distribution to Gaussian-like distribution. This task is performed by two different methods in two different PAPR techniques. The first method of PAPR reduction is done by the addition of complex Gaussian random signals, while the second one is done by insertion of dummy Gaussian subcarriers. The two techniques provide PAPR reduction in the order of 5 dB for PSK-OFDM systems with no out-of-band radiation. The adaptive operation of these techniques enhances significantly both the BER performance and reduce the transmission power. The last part of this thesis presents a new modulation-based error resilient technique referred to as multi-dimensional modulation technique (MDM). In this technique concatenation of digital modulators of decreasing modulation orders are employed. The MDM technique improves the BER performance linearly with increased size of modulation order; up to 12 dB improvement in Eb/No is achieved relative to the conventional OFDM systems at high modulation orders, M≥1024. Also, the MDM technique offers both error resilience and PAPR reduction when it is combined with the conventional OFDM systems in time domain. As a conclusion, the proposed techniques described above offer new solutions to the problem of high PAPR in OFDM systems, and for one of them offer improvement of BER performance at the same time. Besides, they can be applied for different systems parameters and applications requirement. Moreover, the PAPR reduction techniques proposed in this thesis are data-independent and can be implemented in one-shot; while the MDM technique uses only digital modulation and dc-offset signal processing, which can be implemented by simple circuits and/or processors.
Book Synopsis OFDM Systems for Wireless Communications by : Adarsh Narasimhamurthy
Download or read book OFDM Systems for Wireless Communications written by Adarsh Narasimhamurthy and published by Morgan & Claypool Publishers. This book was released on 2010-02-02 with total page 78 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
Book Synopsis Minimizing Peak-to-average Power Ratio in an Orthogonal Frequency Division Multiplex System by :
Download or read book Minimizing Peak-to-average Power Ratio in an Orthogonal Frequency Division Multiplex System written by and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal frequency division multiplexing (OFDM) is a popular standard in wireless communication for its enabling high throughput data transfer. However, the OFDM signal usually has a high peak-to-average power ratio (PAPR), which requires a wide-dynamic-range, powerconsuming amplifier. Whenever the signal peak is greater than the amplifier linear region, the signal is distorted. This distortion generates interference in both in-band and out-of-band spectrum. The effect of in-band interference becomes apparent at medium to high SNR levels and reduces system performance gains as the SNR increases. We endeavor to improve the system BER by minimizing the signal peak using signal scrambling techniques. These techniques effectively reduce the signal peak and enhance system performance when the receiver is able to correctly decode the scrambling information. This information is a weakness of existing techniques because a resource is needed to transport it, and its corruption dramatically undermines system performance. We propose a novel scheme that utilizes resources allotted for channel estimation and does not need to transmit explicit scrambling information. Therefore, our technique improves over the existing ones in the same category. In addition, we propose some procedures to alleviate scrambling information corruption and show discernible advancements. We study the trade-off between PAPR reduction and channel estimation when they have to compete for the same resource. We suggest doing PAPR reduction only when the receiver can obtain a good channel estimate to ensure favorable system performance.
Book Synopsis New Peak-to-average Power Ratio Reduction Schemes for OFDM Systems by : Peng Liu
Download or read book New Peak-to-average Power Ratio Reduction Schemes for OFDM Systems written by Peng Liu and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is known that the orthogonal frequency division multiplexing (OFDM) modulation is very suitable for high-speed wireless transmission systems due to its bandwidth efficiency and ability in coping with multipath fading. However, the large peak-to-average power ratio (PAPR) of an OFDM signal limits the application of OFDM to a certain degree. The research focus of this thesis is on the study of some new PAPR reduction schemes for OFDM systems. In the first part of the thesis, we investigate the peak windowing method, the clipping method, and a combination of the two techniques with an emphasis on the performance assessment of the transmitted OFDM signal using the combination scheme. We start with the review of the two typical signal distortion techniques and point out their advantages and shortcomings. We then propose a combination scheme for the two techniques in order to overcome their drawbacks. In the proposed combination scheme, a weighting function is used to remove instantaneous signal peaks and then a hard-limiting is utilized for the reduction of the overall peak powers. A modified IDFT interpolation is developed and employed in the combination scheme to improve the interpolation precision of the time-domain OFDM signal. (Abstract shortened by UMI.).
Book Synopsis A New Scheme for Reduction of Peak-to-average Power Ratio in Orthogonal Frequency Division Multiplexing by : Ahmed Mustafa H. Melad
Download or read book A New Scheme for Reduction of Peak-to-average Power Ratio in Orthogonal Frequency Division Multiplexing written by Ahmed Mustafa H. Melad and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal Frequency Division Multiplexing (OFDM) is an attractive modulation method ror channels with a non-flat frequency response. as it saves the need for complex equalizers. However. its main disadvantage is the high peak-to-average power ratio (PAPR) of the output signal, which may take values within a range that is proportional to the number of carriers in the system. As a result, a linear behavior of the system over a large dynamic range is needed and therefore the efficiency of the output amplifier is reduced. Many methods have been proposed to reduce the PAPR of the OFDM signal. among them a clipping technique which has been focused and investigated. OFDM signal, among them a clipping technique which has been focused and investigated. This thesis proposes a new scheme to reduce the PAPR. We name it Off technique. Further the effects of clipping scheme as well as the new scheme on the OFDM system performance in terms of Bit Error Rate (BER) and PAPR reduction is investigated. The results obtained indicate that both parameters, i.e. the reduction in PAPR and BER of this scheme were worse than those of the Clipping Scheme. In conclusion, results indicate that Off Technique does not offer a better solution to P APR reduction in the OFDM system.
Book Synopsis Selective Mapping technique for PAPR reduction in LTE-OFDM Systems by : Neelam Dewangan
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.
Book Synopsis Improvement of Papr Reduction for Ofdm Signal in Lte System by : Md. Munjure Mowla
Download or read book Improvement of Papr Reduction for Ofdm Signal in Lte System written by Md. Munjure Mowla and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last couple of years, wireless communications have experienced a quick growth due to the ubiquitous mobility, super internet speed and huge multimedia services & applications. Orthogonal frequency division multiplexing (OFDM) is an emerging research field of wireless communication and finds its application where high data rate is required at low latency and better spectral efficiency. OFDM signals have a generic problem of high peak to average power ratio (PAPR) which is defined as the ratio of the peak power to the average power of the OFDM signal. The drawback of high PAPR is that the dynamic range of the power amplifier (PA) and digital-to-analog converter (DAC) during the transmission and reception of the signal is higher. The main focus of this research is to design & implement a new PAPR reduction scheme based on amplitude clipping & filtering method which reduces the PAPR significantly. Simulation results show the considerable improvement in case of PAPR reduction compare to an existing method. Besides these, overview, motivation & different types of analysis of PAPR reduction techniques are discussed in this book.
Book Synopsis Peak-to-average Power Ratio Reduction in Orthogonal Frequency Division Multiplexing by : Sidharth Khanna
Download or read book Peak-to-average Power Ratio Reduction in Orthogonal Frequency Division Multiplexing written by Sidharth Khanna and published by . This book was released on 2007 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Wireless OFDM and MIMO-OFDM Communications by : P. Mukunthan
Download or read book Wireless OFDM and MIMO-OFDM Communications written by P. Mukunthan and published by LAP Lambert Academic Publishing. This book was released on 2014-06-14 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present wireless systems aim for two conflicting goals, viz., providing quality of service such as delay, fairness to users, and maximizing the throughput of the system. Several techniques have been developed for increasing bandwidth with high data rate. Among these techniques, Orthogonal Frequency Division Multiplexing (OFDM) is a special form of multicarrier technique where all the subcarriers are orthogonal to each other. OFDM offers higher data rate and high immunity to the multipath fading channel without degrading the Bit Error Rate (BER) performance. It has gained popularity for broadband communication system because of its high spectral efficiency and capacity to combat multipath fading. At the same time, it has some limitations such as Inter-Symbol Interference (ISI), Inter-Carrier Interference (ICI) and high Peak-to-Average Power Ratio (PAPR). This book contain seven chapters and an attempt has been made in this research work to enhance the power amplifier efficiency and reduce the high PAPR of the OFDM and MIMO-OFDM systems through modified PTS approach combined with some PAPR reduction techniques.
Book Synopsis The Orthogonal Frequency Division Multiplexing (OFDM). Introduction and explanation of five different types of techniques by : Dr. Lokesh Chikkananjaiah
Download or read book The Orthogonal Frequency Division Multiplexing (OFDM). Introduction and explanation of five different types of techniques written by Dr. Lokesh Chikkananjaiah and published by GRIN Verlag. This book was released on 2021-02-25 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thesis (M.A.) from the year 2019 in the subject Electrotechnology, grade: 9, , language: English, abstract: The Orthogonal Frequency Division Multiplexing (OFDM) is an important aspect of multicarrier digital data transmission system where a single data stream is transmitted into a several number of lower rates subcarrier signals. In this thesis, there are five different types of the techniques introduced to strengthen the communication quality and capacity. This kind of new standard of transmission of data is the first one to perform with OFDM in data packet based communication system. In wireless communication network, the abstraction of parallel transmission of data symbols is implemented to attain high throughput and effective transmission quality. The OFDM is a method to deal with parallel transmission.
Book Synopsis Reducing Peak to Average Power Ratio of OFDM by Using Selected Mapping by : Wanis Mohamed
Download or read book Reducing Peak to Average Power Ratio of OFDM by Using Selected Mapping written by Wanis Mohamed and published by . This book was released on 2012 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Orthogonal frequency division multiplexing (OFDM) has become the most popular modulation technique for high speed data transmission. However, high peak to average power ratio (PAPR) is a major drawback of this modulation technique, because high peak reduces the power efficiency of the RF power amplifier at transmitter. This project gives an overview of the popular OFDM reduction techniques, and indicates that selected mapping (SLM) is a promising reduction technique.
Book Synopsis An Investigation of Peak-To-Average Power Reduction by : Yi Wang
Download or read book An Investigation of Peak-To-Average Power Reduction written by Yi Wang and published by LAP Lambert Academic Publishing. This book was released on 2010-06 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) technology is one of the most attractive candidates for fourth generation(4G)mobile radio communication. It effectively combats the multipath fading channel and improves the bandwidth efficiency. At the same time, it also increases system capacity so as to provide a reliable transmission. However, the main drawback of MIMO-OFDM system is high peak-to-average power ratio (PAPR) for large number of sub-carriers, which result in many restrictions for practical applications. Coding, phase rotation and clipping are among many PAPR reduction schemes that have been proposed to overcome this problem. In this thesis, we will mainly investigate the PAPR reduction performance with two different PAPR reduction methods: partial transmit sequence (PTS) and selective mapping(SLM). These two methods are sub- entities of phase rotation scheme. In addition, several corresponding modified algorithms are studied with respect to balanced performance and applicability.
