29 research outputs found

    New scheme for PAPR reduction in FBMC-OQAM systems based on combining TR and deep clipping techniques

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    Filter bank multi-carrier with offset quadrature amplitude modulation (FBMC-OQAM) system is a very efficient multicarrier modulation technique for 5G, but it suffers as all multicarriers designs from large peak-to-average power ratio (PAPR). Tone reservation (TR) is a method designed to solve this problem by reserving several subcarriers called tones in the frequency domain to generate a cancellation signal in the time domain to eliminate high peaks. In this paper, we suggest a serial combination of tone reservation (TR) method with an enhanced version of clipping called deep clipping (DC) method (TR&DC) to enhance the peaks (PAPR) mitigation in FBMC-OQAM signal model without significantly impacting the quality of transmission. Numerical results and analysis show that the new TR&DC approach allows better overall performance and offers remarkable gain in term of PAPR mitigation than the TR method, with similar BER performance to TR over additive white gaussian noise channel and Rapp HPA model

    A Novel PAPR Reduction in Filter Bank Multi-Carrier (FBMC) with Offset Quadrature Amplitude Modulation (OQAM) Based VLC Systems

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    The peak to average power ratio (PAPR) is one of the major problem with multicarrier-based systems. Due to its improved spectral efficiency and decreased PAPR, Filter Bank Multicarrier (FBMC) has recently become an effective alternative to the orthogonal multiplexing division (OFDM). For filter bank multicarrier communication/offset quadrature amplitude modulation-Visible light communication (FBMC/OQAM-VLC) systems is proposed a PAPR reduction technique. The suggested approach overlaps the proposed FBMC/OQAM-based VLC data signal with the existing signals. Non-redundant signals and data signals do not overlap in the frequency domain because data signals are scattered on odd subcarriers whereas built signals use even subcarriers. To reduce the effects of large-amplitude signal reduction, the suggested technique converts negative signals into positive signals rather than clipping them off as in conventional FBMC-based VLC systems. The PAPR reduction and bit error rate (BER) are realized using a scaling factor in the transformed signals. Complementary cumulative distribution function(CCDF) and BER are used to calculate the performance of the proposed approach. The presented study found that FBMC/OQAM-VLC systems to achieve a good trade-off between PAPR reduction and BER

    Constrained RS coding for Low Peak to Average Power Ratio in FBMC -- OQAM Systems

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    Multi-carrier modulation techniques have now become a standard in many communication protocols. Filter bank based multi-carrier (FBMC) generation techniques have been discussed in the literature as a means for overcoming the shortcomings of IFFT/FFT based OFDM system. The Peak to Average Power Ratio (PAPR) is a problem faced by all multi-carrier techniques. This paper discusses the methods for reducing PAPR in a FBMC system while maintaining acceptable Bit Error Rate (BER). A new PAPR minimizing scheme called Constrained Reed Solomon (CRS) coding is proposed. The hybrid techniques using coding and companding are tested for different channel models and is found to yield promising results.Comment: 6 pages,6 Figures, Journal of Electrical and Electronics Engineerin

    Modified Alternative-signal Technique for Sequential Optimisation for PAPR Reduction in OFDM-OQAM Systems

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    A modified alternative signal technique for reducing peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing systems employing offset quadrature amplitude modulation (OFDM-OQAM) is proposed. Lower PAPR reduces the complexity of digital to analog converters and results in increasing the efficiency of power amplifiers. The main objective of the algorithm is to decrease PAPR with low complexity. The alternative signal method involves the individual alternative signal (AS-I) and combined alternative signal (AS-C) algorithms. Both the algorithms decrease the peak to average power ratio of OFDM-OQAM signals and AS-C algorithm performs better in decreasing PAPR. However the complexity of AS-C algorithm is very high compared to that of AS-I. To achieve reduction in PAPR with low complexity, modified alternative signal technique with sequential optimisation (MAS-S) is proposed. The quantitative PAPR analysis and complexity analysis of the proposed algorithm are carried out. It is demonstrated that MAS-S algorithm simultaneously achieves PAPR reduction and low complexity

    Уменьшение PAPR в системах FBMC-OQAM на основе дискретного преобразования скользящей нормы

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    Полный текст доступен на сайте издания по подписке: http://radio.kpi.ua/article/view/S0021347019020018Работа посвящена преодолению недостатка, связанного с величиной отношения пикового уровня мощности сигнала к среднему PAPR (Peak to Average Power Ratio), возникающего при нескольких несущих в банке фильтров FBMC (Filter-Bank Multi-Carriers) с квадратурной амплитудной модуляцией со сдвигом OQAM (Offset-QAM) в системах FBMC-OQAM, которые являются кандидатом при формировании формы сигнала для беспроводных систем связи пятого поколения. Дискретное преобразование скользящей нормы DSNT (Discrete Sliding Norm Transform) после обратного дискретного преобразования Фурье IDFT (Inverse Discrete Fourier Transform) предлагается на основе L2-метрики и нормы для пяти отсчетов при каждой операции скольжения. В предлагаемом составе L2-на-5 DSNT рассматривается использование перекрывающейся структуры FBMC-OQAM. Это существенно уменьшает величину PAPR в системах FBMC-OQAM, что гарантирует линейность характеристики усилителя большой мощности HPA (High Power Amplifier) и позволяет избежать искажения сигнала. Основные достоинства этой методики состоят в уменьшении вычислительной сложности по сравнению с известными методиками и отсутствии необходимости в какой-либо дополнительной информации SI (Side Information) на стороне приемника. Результаты моделирования показали, что методика L2-на-5 DSNT позволяет достичь 40% уменьшения величины PAPR при CCDF = 10^(–3) по сравнению с исходной системой FBMC-OQAM

    Enhanced Multicarrier Techniques for Professional Ad-Hoc and Cell-Based Communications (EMPhAtiC) Document Number D3.3 Reduction of PAPR and non linearities effects

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    Livrable d'un projet Européen EMPHATICLike other multicarrier modulation techniques, FBMC suffers from high peak-to-average power ratio (PAPR), impacting its performance in the presence of a nonlinear high power amplifier (HPA) in two ways. The first impact is an in-band distortion affecting the error rate performance of the link. The second impact is an out-of-band effect appearing as power spectral density (PSD) regrowth, making the coexistence between FBMC based broad-band Professional Mobile Radio (PMR) systems with existing narrowband systems difficult to achieve. This report addresses first the theoretical analysis of in-band HPA distortions in terms of Bit Error Rate. Also, the out-of band impact of HPA nonlinearities is studied in terms of PSD regrowth prediction. Furthermore, the problem of PAPR reduction is addressed along with some HPA linearization techniques and nonlinearity compensation approaches

    Numerical Simulation and Design of Low PAPR FBMC Communication System for 5G Applications

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    Unlike SC-FDMA (Single-Carrier Frequency Division Multiple Access), merging only DFT (Discrete Fourier Transform) addition with FBMC-OQAM (filter group multi-carrier with offset quadrature amplitude modulation) only cuts the marginal PAPR. (Peak-to-average power ratio). To take advantage of the single carrier effect of DFT extension, special conditions for the coefficients of the IQ (in-phase and quadrature phase) channels of every single subcarrier ought to be met. As a beginning point, we first originate this form, which we call the ITSM (Identical Time-Shifted Multi-Carrier) condition. Then, depending on this condition, we put forward a new FBMC for low PAPR. The foremost features of the offered way out are summarized as: First, to additionally raise the PAPR reduction, we created four candidate versions of the FBMC waveform for DFT spreading out and ITSM conditions and carefully chosen one with the least peak power. Even with various candidate generations, unlike the traditional SI (Side information) based PAPR reduction scheme, the focal computational fragments (such as DFT and IDFT) are shared and need only be executed one time. Therefore, matched to the prior DFT-expanded FBMC, the overhead in complexity is small, and the recommended pattern can realize a PAPR reduction comparable to SC-FDMA. Second, in the projected pattern each one pass on only two bits of SI from a block of FBMC-OQAM symbols. And so, the SI overhead is meaningfully lesser than a conventional SI-based scheme such as SLM (Selective Mapping) or PTS (Partial Transmission Sequence).The whole work is executed using MATLAB software. The PAPR of FBMC system has been significantly reduced after the application of proposed algorithm. PAPR was reduced by 25 % after the use of DFT spreading and ITSM conditioning

    Analysis of PAPR Reduction in 5G communication

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    The goal of this thesis is to analyze PAPR reduction performance in 5G communication. 5G communication technology is beyond 4G and LTE technology and expected to be employed around 2020. Research is going on for standardization of 5G technology. One of the key objective of 5G technology is to achieve high data rate (10Gbps). For this a large bandwidth is needed. Since limited frequency resources are available, the frequency spectrum should be efficiently utilized to obtain high data rate. Also to utilize white space, cognitive radio networks are needed. In cognitive radio network very low out of band radiation is desired. OFDM is used in 4G communication but it has the drawback of low spectral efficiency and high out of band radiation, which makes it a poor choice for 5G communication. So for 5G communication new waveform is required. FBMC, UFMC, GFDM are some of the waveform candidates for 5G communication. FBMC is a potential candidate for 5G communication and it is used in many 5G projects around the world. In this thesis FBMC is used as a waveform candidate for 5G communication. High PAPR is always a problem in multicarrier communication system. FBMC is also a multicarrier communication system, so it also suffers from high PAPR problem. To reduce the PAPR several PAPR reduction techniques have been proposed over the last few decades. Tone injection and companding are two promising techniques, which are used in PAPR reduction of multicarrier communication system. In this thesis a combined scheme of tone injection and companding is used, which gives significant performance improvement compared to the tone injection and companding techniques taken separately. Simulation is performed to analyses the PAPR and BER performance of FBMC-FMT and FBMC-SMT system. Also a new clipping based PAPR reduction scheme is proposed in this thesis. For this scheme simulation is performed to analyze the PAPR performance of FBMC-FMT, FBMC-SMT and FBMC-CMT system. All the simulations are performed in MATLAB

    Subcarrier Filtering For Spectrally Efficient Multicarrier Modulation Schemes and Its Impact on PAPR: A Unified Approach

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    Multicarrier modulation (MCM) based schemes have been a major contributing factor in revolutionizing cellular networks due to their ability to overcome fading. One of the popular scheme orthogonal frequency division multiple access (OFDMA), having been part of 4G, is also adapted as part of 5G enhanced mobile broadband (eMBB).  Though it has several advantages, spectral efficiency (SE) and peak to average power ratio (PAPR) have been two major concerns which have attracted lot of attention resulting in proposals of several other MCM schemes.  But most of these studies have treated the two issues independently. This paper in particular studies the subcarrier filtering approach to improve the spectral efficiency of MCM scheme and its impact on the overall PAPR of such schemes. The analysis shows that the PAPR improvement is also achieved by such filters meant for spectral confinement and the simulation results validate the same provoking a unified research direction less explored till now

    Subcarrier Filtering For Spectrally Efficient Multicarrier Modulation Schemes and Its Impact on PAPR: A Unified Approach

    Get PDF
    Multicarrier modulation (MCM) based schemes have been a major contributing factor in revolutionizing cellular networks due to their ability to overcome fading. One of the popular scheme orthogonal frequency division multiple access (OFDMA), having been part of 4G, is also adapted as part of 5G enhanced mobile broadband (eMBB).  Though it has several advantages, spectral efficiency (SE) and peak to average power ratio (PAPR) have been two major concerns which have attracted lot of attention resulting in proposals of several other MCM schemes.  But most of these studies have treated the two issues independently. This paper in particular studies the subcarrier filtering approach to improve the spectral efficiency of MCM scheme and its impact on the overall PAPR of such schemes. The analysis shows that the PAPR improvement is also achieved by such filters meant for spectral confinement and the simulation results validate the same provoking a unified research direction less explored till now
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