scholarly journals PAPR reduction for FBMC/OQAM using hybrid scheme of different Precoding transform and mu-law companding

2017 ◽  
Vol 6 (4) ◽  
pp. 154 ◽  
Author(s):  
Imad Shaheen ◽  
Abdelhalim Zekry ◽  
Fatma Newagy ◽  
Reem Ibrahim

The filter banks multicarrier with offset quadrature amplitude modulation (FBMC/OQAM) is developing multicarrier modulation technique used in the next wireless communication system (5G). FBMC/OQAM supports high data rate and high band width efficiency. However, one of the major drawbacks of FBMC system is high peak to Average Power Ratio (PAPR) of the transmitted signal, which causes serious degradation in performance of the system. Therefore, it is required to use a proper PAPR scheme at the transmitter to reduce the PAPR. In this paper, a hybrid scheme is investigated with the combination of preceding transform technique and Mu Law Companding technique to reduce PAPR in FBMC systems. Moreover, four preceding techniques are examined to find the best Precoding technique which can be used with Mu law commanding. We assessed the discrete Hartley transform (DHT). The discrete cosine transformed (DCT), the Discrete Sine Transform (DST), and the Walsh Hadamard transforms (WHT) which are applied separately with Mu Companding. The numerical results verify that the FBMC systems with all Precoding technique combined with Mu law commanding can improve PAPR performance of the signals greatly with the best results achieved when the combination scheme consists of the DST Precoding and Mu law commanding for both PAPR and BER performance.

2019 ◽  
Vol 8 (2S11) ◽  
pp. 3147-3150

Extreme Peak to Average Power Ratio (PAPR) is as yet the common significant test in Orthogonal Frequency Division Multiplexing (OFDM) framework. A consolidated strategy of Discrete Cosine Transform (DCT) and Discrete Sine Transform (DST) precoding based CSD procedure for PAPR decrease in OFDM frameworks are represented in this article. Here, the constants are spoken to utilizing a canonic signed digit (CSD) depiction. For bit-positions relating to a positive digit in the CSD portrayal, the bit-item is included that segment. For negative digits in the CSD portrayal, a one-piece two's supplement portrayal is utilized. To evade sign-expansion a remuneration vector is utilized. Analyzed results demonstrate that our proposed procedure can diminish the PAPR performance very effectively than following the conventional PAPR lessening methods.


2021 ◽  
Vol 9 (2) ◽  
pp. 1178-1185
Author(s):  
Kiranmai Babburu , Et. al.

The radiofrequency method of transmission suffers from the problem of the limited licensed radio frequency spectrum, & security, wide EMI (electromagnetic interference), high multipath fading & power consumption for short-range applications. The solution to these problems can be achieved by using optical wireless communication technique called the Visible Light Communication system where the data is sent through regulated emission of light. The transmission of digital image information productively in the present optical wireless communication framework is an uphill task as these systems often suffer from problems like frequency selective fading propagation losses and inter-symbol interferences. In order to conquer such difficulties we hereby propose a robust method to transfer the digital image through a Multi-Carrier Modulation Scheme-MMS. In this paper, an Image-Based Multicarrier modulation VLC system is designed through which is sent a corrupted Digital Image with additive white Gaussian noise and explored the overall execution of the Image based Multicarrier modulation VLC system at distinct SNR values.  The paper also addresses the issue of high Peak to Average Power Ratio (PAPR) in Multicarrier modulation and reduced it by using different PAPR reduction techniques. The received image quality of the proposed system is obtained under different signal to noise ratios at different modulation schemes..


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shiv Om Tiwari ◽  
Rajeev Paulus

Abstract Orthogonal frequency division multiplexing (OFDM) revolutionizes the transmission technologies, including, optical as well as wireless communication. In OFDM the orthogonal nature of carriers makes it very good technique for data transfer. Still the out-of-band (OOB) radiation in OFDM leads to inter symbol interference (ISI) and bit error rate (BER) goes down. Moreover amplitude variations of the subcarriers lead to power variations and peak-to-average power ratio (PAPR) problem. To overcome these issues a novel filter bank multicarrier (FBMC) scheme is proposed, where each carrier is allowed to pass through to a separate filter and orthogonality among subcarriers is relaxed. Thus FBMC has better OOB and PAPR performance. In this work, we also have evaluated the PAPR performance by the simulation results. For the improvement of PAPR nonlinear companding scheme along with clipping is presented. The hybrid technique (clipping + companding) parameters are set in such a way that PAPR is reduced while signal power remains constant. Results are also compared with recent methods and it has been found that the proposed technique preforms better than other chosen techniques.


Author(s):  
Tahreer Mahmood ◽  
Seshadri Mohan

Multiple-input multiple-output technology together with orthogonal frequency division multiplexing (MIMO-OFDM) is an effective technique to combat multi-channel fading and to improve bandwidth efficiency. Simultaneously, it also increases the system's ability to provide reliable transmission. However, the main disadvantage of OFDM is the high peak-to-average-power ratio (PAPR), which, if not mitigated, will negatively impact practical applications. The high PAPR increases complexity and Bit Error Rate. In this research, the authors investigate the factors influencing the PAPR performance of both OFDM and MIMO-OFDM systems. The objective of this research is to make researchers in this field become familiar with this problem as well as to impart an understanding of the factors that influence PAPR. In this study, the authors classify the factors that impact PAPR into modulation schemes and a number of sub-carriers. These parameters influence the PAPR performance have been analyzed and simulated by using MATLAB. It is observed that the numbers of sub-carriers have a great effect on the PAPR performance. However, modulation schemes can have a small effect on PAPR performance.


Author(s):  
Ahmed M. Sana ◽  
Amer T. Saeed ◽  
Yaseen Kh. Yaseen

<p>Adaptive quadrature amplitude modulation (QAM) is a crucial scheme that enables the modern communication systems to overcome the adverse effects of channel fluctuations and maintain an acceptable spectral efficiency. In order to enhance adaptive modulation even further, adoption of odd-bit QAM constellations alongside even constellations had been suggested to improve the transmission efficiency of adaptive QAM modulation. Hence, odd-bit QAM had been extensively studied, analyzed, and tested by many researchers for various patterns, sizes, and communication systems in terms of bit error rate (BER) and peak to average power ratio (PAPR). However, the PAPR performance of odd-bit QAM constellation with single carrier transmission systems adopted in the uplink of the 4G long term evolution (LTE) standards caught almost no research interest. In this paper, the PAPR performance of both cross and rectangular odd-bit QAM constellations are investigated for DFT-S-OFDM systems. Complementary cumulative distribution functions (CCDFs) and probability density functions (PDFs) curves for PAPR are also obtained. Finally, an equation for PAPR PDF is empirically derived for odd-bit cross QAM based DFT-S-OFDM. The results show that cross odd-bit QAM outperforms the rectangular odd-bit QAM in terms of PAPR by 1.02 dB for 8-QAM and 1.3 dB for 32-QAM. This proves that cross odd-bit QAM is a better choice in terms of PAPR for DFT-S-OFDM systems. </p>


Author(s):  
Pornpawit Boonsrimuang ◽  
Kanchana Limwattanacha ◽  
Pisit Boonsrimuang ◽  
Hideo Kobayashi

Many PAPR reduction methods for OFDM time domain signal have been proposed up to today, all of which can be classified into two kinds of methods as the distortion and distortion-less methods. The most of distortion-less methods show better PAPR performance without degradation of BER performance. However the distortion-less methods are usually required to control the transmission data information so as to minimize the PAPR performance at the transmitter. From this fact, the distortion-less methods are required to inform the controlled information as the side information to the receiver for the correct demodulation of data information. The side information is usually informed to the receiver with the higher signal quality by using the separate channel or the embedded in the data information which would lead the degradation of transmission efficiency and the increase of hardware complexity of transmitter and receiver. This paper proposes a novel distortion-less PAPR reduction method which employs the permutation of subcarriers in the frequency domain. The feature of proposed method is to achieve the better PAPR performance with a very few embedded side information for the correct demodulation of data information at the receiver. This paper presents various computer simulation results to verify the effectiveness of proposed method as comparing with the conventional OFDM method in the non-linear channel.


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