scholarly journals Evaluation of Clipping and Filtering-Based PAPR Reduction in OFDM System

2017 ◽  
Vol 1 (2) ◽  
pp. 18
Author(s):  
N. M. A. E. D. Wirastuti ◽  
N. Pramaita ◽  
I M. A. Suyadnya ◽  
D. C. Khrisne
Keyword(s):  
Fourier Transform ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Average Power ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Parallel Data ◽  
Serial Data ◽  
Filtering Technique ◽  
Clipping And Filtering

This paper investigates clipping and filtering techniques in reducing peak average power ratio (PAPR) of Orthogonal Frequency Division Multiplexing (OFDM) system. The concept of OFDM is to split a high speed serial data into parallel data at a lower speed, then the parallel data carried by mutually orthogonal subcarriers. The high of PAPR is one of disadvantages of OFDM system. The high PAPR can damages the form of OFDM and reduces its performance. The purpose of this study is to reduce PAPR using simulation. OFDM was simulated with and without clipping filtering then compared.  The methods used to reduce PAPR was clipping and filtering technique. Clipping and filtering technique operates by clipping the output of inverse Fourier transform that exceed the threshold. Graphics PAPR vs. CCDF was used to evaluate the performance of OFDM systems. PAPR for OFDM system using Fourier transform when CCDF = 10-3 is 11,2 dB, with classical clipping PAPR was 4,1 dB and PAPR 4,6 dB when with deep clipping.

scholarly journals PAPR Reduction an effective approach for next frontier MIMO-OFDM systems

2021 ◽  
Vol 9 ◽  
Author(s):  
Balram Damodhar Timande ◽  
◽  
Dr. Manoj Kumar Nigam ◽  
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Input Multiple Output ◽  
Average Power ◽  
Error Rates ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Saturation Region ◽  
Selective Mapping ◽  
Clipping And Filtering

The ‘Orthogonal frequency division multiplexing (OFDM)’ is a well-accepted and effective technology employed today and in future wireless communication systems. The combinations of OFDM and ‘multiple-input multiple-output (MIMO’) offer high quality of services and better throughput. The multicarrier OFDM system experiences a high ‘peak-to-average power ratio (PAPR’), which is the major issue in the OFDM scheme and must be truncated to achieve trustworthy communication. Due to high PAPR in a signal to be transmitted, the power amplifier in the transmitter section enters into saturation region and amplifies the signal nonlinearly, resulting in loss of orthogonality and ultimately in ‘inter-carrier interference (ICI)’. In this article, the 'iterative clipping and filtering (ICF)' method is proposed to minimize the PAPR in the OFDM system. The simulation is carried out using MATLAB (version 2014b). The result of the proposed ICF method and the ‘selective mapping (SLM)’ scheme is analyzed and compared. From the analysis, it is shown that the proposed ICF technique is more suitable for minimizing the PAPR effectively without affecting ‘bit error rates (BER)’ much and the simplicity of the system. The simulation result of the proposed ICF scheme using ‘Quadrature Phase Shift Keying (QPSK)’, FFT size of 128, and clipping and filtering level up to 6 shows that the proposed ICF scheme for clipping level of 6 reduces PAPR to 5dB. Also, the BER is minimized at the level of 3×10−5 at 12 dB SNR.

Generalized Trapezoidal Companding Technique for PAPR Reduction in OFDM Systems

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Saruti Gupta ◽  
Ashish Goel
Keyword(s):  
Bit Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Frequency Division ◽  
Performance Parameters ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Ofdm Signal ◽  
Specific Degree ◽  
Ofdm Signals

Abstract The main drawback in the performance of the Orthogonal Frequency Division Multiplexing (OFDM) system is the higher Peak-to-Average Power Ratio (PAPR) of the OFDM signals at the transmitter side. Companding is a well-known technique useful for reducing PAPR in the OFDM signal. This paper proposes a new nonlinear companding scheme that transforms the magnitude of Rayleigh distributed OFDM signal of specific degree into trapezoidal distribution. Additional design parameter is used in the proposed companding scheme to make the companding function more flexible. In the designed OFDM system the companding function has more degree of freedom which improves the PAPR and bit error rate (BER) parameters of the designed system. It has been demonstrated that the designed companding scheme provides more flexibility to accomplish an optimum trade-off between the performance parameters PAPR and BER of the designed OFDM system.

scholarly journals Palm Date Leaf Clipping: A New Method to Reduce PAPR in OFDM Systems

Information ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 190 ◽  
Author(s):  
Brahim Bakkas ◽  
Reda Benkhouya ◽  
Idriss Chana ◽  
Hussain Ben-Azza
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Average Power ◽  
Papr Reduction ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Leaf Clipping ◽  
Hyperbolic Cosine ◽  
Transmitted Signal

Orthogonal frequency division multiplexing (OFDM) is the key technology used in high-speed communication systems. One of the major drawbacks of OFDM systems is the high peak-to-average power ratio (PAPR) of the transmitted signal. The transmitted signal with a high PAPR requires a very large linear range of the Power Amplifier (PA) on the transmitter side. In this paper, we propose and study a new clipping method named Palm Clipping (Palm date leaf) based on hyperbolic cosine. To evaluate and analyze its performance in terms of the PAPR and Bit Error Rate (BER), we performed some computer simulations by varying the Clipping Ratio (CR) and modulation schemes. The obtained results show that it is possible to achieve a gain of between 7 and 9 dB in terms of PAPR reduction depending on the type of modulation. In addition, comparison with several techniques in terms of PAPR and BER shows that our method is a strong alternative that can be adopted as a PAPR reduction technique for OFDM-based communication systems.

scholarly journals A CCM-Based OFDM System with Low PAPR for Sparse Source

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Qinbiao Yang ◽  
Zulin Wang ◽  
Qin Huang
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Coded Modulation ◽  
High Peak ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm System ◽  
Simulation Results ◽  
Clipping And Filtering

Orthogonal frequency division multiplexing (OFDM) usually suffers high peak-to-average power ratio (PAPR). As shown in this paper, PAPR becomes even severe for sparse source due to many identical nonzero frequency OFDM symbols. Thus, this paper introduces compressive coded modulation (CCM) in order to restrain PAPR by reducing identical nonzero frequency symbols for sparse source. As a result, the proposed CCM-based OFDM system, together with iterative clipping and filtering, can efficiently restrain the high PAPR for sparse source. Simulation results show that it outperforms about 4 dB over the traditional OFDM system when source sparsity is 0.1.

Optimization and Simulation of OFDM System Based on Orthogonal Wavelet

2014 ◽  
Vol 548-549 ◽  
pp. 1221-1226
Author(s):  
Zeng You Sun ◽  
Fan Ming Zeng
Keyword(s):  
Fourier Transform ◽  
Discrete Fourier Transform ◽  
Orthogonal Frequency Division Multiplexing ◽  
Modulation Method ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Orthogonal Wavelet ◽  
Optimization And Simulation

In order to reduce the Orthogonal Frequency division Multiplexing (OFDM) Inter-Carrier Interference (ICI), Put forward a kind of modulation method that based on the orthogonal frequency division multiplexing of orthogonal wavelet, Using orthogonal wavelet instead of discrete Fourier transform, optimize the design for OFDM systems, on the premise of without protection interval to reduce the system interference, using MATLAB to simulate the OFDM system, results show that the optimization of the OFDM can reduce the power of the ICI and Inter-symbol Interference (ISI) and improve the comprehensive anti-jamming of the OFDM system.

scholarly journals Three Term Weighted Type Fractional Fourier Transform Based Generalized Hybrid Carrier and Its Application into PAPR Suppression

2021 ◽  
Author(s):  
Yong Li ◽  
Zhiqun Song ◽  
Teng Sun ◽  
Bin Wang
Keyword(s):  
Fourier Transform ◽  
Orthogonal Frequency Division Multiplexing ◽  
Fractional Fourier Transform ◽  
Average Power ◽  
The Novel ◽  
Cumulative Density Function ◽  
Ofdm System ◽  
Single Carrier ◽  
Definition Of ◽  
Weighted Type

To suppress the peak to average power ratio (PAPR) of wireless communication based upon multi-carrier system. We, in this paper, proposed the three term weighted type fractional Fourier transform (3-WFRFT) based generalized hybrid carrier (GHC) system. We first provide the definition of 3-WFRFT. Moreover, some useful properties of 3-WFRFT have been presented, in this paper, which will helpful to comprehend the novel 3-WFRFT transform. Furthermore, we take PAPR of the proposed algorithm, in comparison with orthogonal frequency division multiplexing (OFDM) system and single carrier modulation (SC) system under typical complementary cumulative density function (CCDF) level. It would be demonstrated that, from some numerical simulations, the proposed 3-WFRFT based GHC performs better than OFDM system and will be useful to reduce the PAPR level.

SELECTIVECODEWORD SHIFT (SCS) TECHNIQUE FOR PAPR REDUCTION OF OFDM SYSTEMS

2016 ◽  
Vol 78 (5-9) ◽  
Author(s):  
Ezmin Abdullah ◽  
Azlina Idris
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Side Information ◽  
Average Power ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Data Sequence ◽  
Wireless Applications ◽  
Selective Mapping ◽  
Ofdm Signals ◽  
Peak Value

Peak to Average Power Ratio (PAPR) has been known to be a common problem in Orthogonal Frequency Division Multiplexing (OFDM). The peak value of power signals has contributed to other problems, thus the implementation of OFDM system in many wireless applications has been growing slowly. There are many techniques being discussed to reduce the PAPR in OFDM systems where one of them is reduction through scrambling. In this paper, a technique that is based on scrambling method in order to reduce high PAPR in OFDM system is introduced. This proposed technique is called the Selective Codeword Shift (SCS). The key idea of SCS is to produce a scramble data sequence where the candidate with minimum PAPR will then be selected for transmission. This has shown an improvement in reducing PAPR as compared to original OFDM signals and the conventional Selective Mapping (SLM) technique with 29.5% improvement. This technique also has the advantage of lower computational complexity as compared to conventional SLM where no multiplication of the phase factor involved in the process and no explicit side information was needed to retrieve the transmitted data at the receiver.

Research on Peak-to-Average Power Ratio for OFDM System

2013 ◽  
Vol 823 ◽  
pp. 366-369
Author(s):  
Hao Fang ◽  
Wan Hua Wei
Keyword(s):  
High Speed ◽  
Data Flow ◽  
Average Power ◽  
Power Ratio ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Major Drawback ◽  
High Power Amplifier ◽  
Flow Through ◽  
Ofdm Signals

OFDM is a special multi-carrier modulation, its basic idea is to make high-speed transmission of data flow through the serial-parallel conversion and make it to be the low-speed transmission of data flow in a number of narrow-band orthogonal sub-channels. However, a major drawback of OFDM signals is their high Peak-to-Average Power Ratio (PAPR), which makes the inter modulation distortion occur due to the nonlinearity of the high power amplifier. The distortion severely deteriorates the performance of the OFDM systems. According the problems mentioned above, this dissertation focuses on the reducing the PAPR algorithms design for OFDM systems, such as SLM and PTS. In summary, this paper has completed the OFDM system simulation with Matlab and analyses the result.

scholarly journals Coherent Optical DFT-Spread OFDM

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Fanggang Wang ◽  
Xiaodong Wang
Keyword(s):  
Bandwidth Allocation ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Minimum Mean Square Error ◽  
Sampling Rate ◽  
Average Power ◽  
Low Complexity ◽  
Ofdm System ◽  
Fiber Optic Communications ◽  
Single Carrier

We consider application of the discrete Fourier transform-spread orthogonal frequency-division multiplexing (DFT-spread OFDM) technique to high-speed fiber optic communications. The DFT-spread OFDM is a form of single-carrier technique that possesses almost all advantages of the multicarrier OFDM technique (such as high spectral efficiency, flexible bandwidth allocation, low sampling rate, and low-complexity equalization). In particular, we consider the optical DFT-spread OFDM system with polarization division multiplexing (PDM) that employs a tone-by-tone linear minimum mean square error (MMSE) equalizer. We show that such a system offers a much lower peak-to-average power ratio (PAPR) performance as well as better bit error rate (BER) performance compared with the optical OFDM system that employs amplitude clipping.

scholarly journals A New-Trend Model-Based to Solve the Peak Power Problems in OFDM Systems

2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Ashraf A. Eltholth ◽  
Adel R. Mekhail ◽  
A. Elshirbini ◽  
M. I. Dessouki ◽  
A. I. Abdelfattah
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Peak Power ◽  
Dynamic Range ◽  
Average Power ◽  
Problem Definition ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Ofdm Signal ◽  
Nonlinear Amplifier ◽  
Power Problem

The high peak to average power ration (PAR) levels of orthogonal frequency division multiplexing (OFDM) signals attract the attention of many researchers during the past decade. Existing approaches that attack this PAR issue are abundant, but no systematic framework or comparison between them exists to date. They sometimes even differ in the problem definition itself and consequently in the basic approach to follow. In this paper, we propose a new trend in mitigating the peak power problem in OFDM system based on modeling the effects of clipping and amplifier nonlinearities in an OFDM system. We showed that the distortion due to these effects is highly related to the dynamic range itself rather than the clipping level or the saturation level of the nonlinear amplifier, and thus we propose two criteria to reduce the dynamic range of the OFDM, namely, the use of MSK modulation and the use of Hadamard transform. Computer simulations of the OFDM system using Matlab are completely matched with the deduced model in terms of OFDM signal quality metrics such as BER, ACPR, and EVM. Also simulation results show that even the reduction of PAR using the two proposed criteria is not significat, and the reduction in the amount of distortion due to HPA is truley delightful.

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