Selective Mapping technique for PAPR reduction in LTE-OFDM Systems

Selective Mapping technique for PAPR reduction in LTE-OFDM Systems PDF Author: Neelam Dewangan
Publisher: GRIN Verlag
ISBN: 3656317364
Category : Technology & Engineering
Languages : en
Pages : 100

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Book Description
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.

Selective Mapping technique for PAPR reduction in LTE-OFDM Systems

Selective Mapping technique for PAPR reduction in LTE-OFDM Systems PDF Author: Neelam Dewangan
Publisher: GRIN Verlag
ISBN: 3656317364
Category : Technology & Engineering
Languages : en
Pages : 100

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Book Description
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.

A Detailed Study of 4G in Wireless Communication: Looking Insight in Issues in OFDM

A Detailed Study of 4G in Wireless Communication: Looking Insight in Issues in OFDM PDF Author: Neelam Dewangan
Publisher: Anchor Academic Publishing (aap_verlag)
ISBN: 3954890844
Category : Business & Economics
Languages : en
Pages : 97

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Book Description
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.

Papr Reduction Techniques in Lte-Ofdm Networks

Papr Reduction Techniques in Lte-Ofdm Networks PDF Author: Neelam Dewangan
Publisher: LAP Lambert Academic Publishing
ISBN: 9783846533086
Category :
Languages : en
Pages : 84

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Book Description
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.

An Improved Selected Mapping Scheme for PAPR Reduction in OFDM Systems

An Improved Selected Mapping Scheme for PAPR Reduction in OFDM Systems PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 75

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Book Description
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.

PAPR and ICI Reduction Techniques for OFDM Based Satellite Communication Systems

PAPR and ICI Reduction Techniques for OFDM Based Satellite Communication Systems PDF Author: Emad Yacoub Qeryaqos Al-Dalakta
Publisher:
ISBN:
Category :
Languages : en
Pages : 177

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Book Description


High Rate Techniques for PAPR Reduction in OFDM Systems

High Rate Techniques for PAPR Reduction in OFDM Systems PDF Author: Sudarshan M. Kannappan
Publisher:
ISBN:
Category :
Languages : en
Pages : 40

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Book Description
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.

PAPR Reduction: Techniques, Analysis and Applications

PAPR Reduction: Techniques, Analysis and Applications PDF Author: Dr. RAJKUMAR L. BIRADAR
Publisher: Archers & Elevators Publishing House
ISBN: 8119385853
Category : Antiques & Collectibles
Languages : en
Pages : 85

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Book Description


PAPR Reduction for OFDM

PAPR Reduction for OFDM PDF Author: William Liu
Publisher:
ISBN: 9781490551586
Category :
Languages : en
Pages : 94

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Book Description
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.

Papr Reduction in Ofdm System Using Pulse Shaping Technique

Papr Reduction in Ofdm System Using Pulse Shaping Technique PDF Author: Prakash Shahi
Publisher: LAP Lambert Academic Publishing
ISBN: 9783844307863
Category :
Languages : en
Pages : 76

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Book Description
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

International Conference on Intelligent Data Communication Technologies and Internet of Things (ICICI) 2018

International Conference on Intelligent Data Communication Technologies and Internet of Things (ICICI) 2018 PDF Author: Jude Hemanth
Publisher: Springer
ISBN: 3030031462
Category : Technology & Engineering
Languages : en
Pages : 1590

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Book Description
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.