scispace - formally typeset
Search or ask a question
Author

Brahim Bakkas

Bio: Brahim Bakkas is an academic researcher from Arts et Métiers ParisTech. The author has contributed to research in topics: Orthogonal frequency-division multiplexing & Companding. The author has an hindex of 1, co-authored 3 publications receiving 3 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: This paper proposes and studies a new clipping method named Palm Clipping (Palm date leaf) based on hyperbolic cosine and shows that it is a strong alternative that can be adopted as a PAPR reduction technique for OFDM-based communication systems.
Abstract: 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.

6 citations

Proceedings ArticleDOI
12 Apr 2019
TL;DR: This work proposes and study a new method based on μ-Law companding type and Polar Codes to reduce PAPR values in a MIMO-OFDM system that operates with less complexity and outperforms the most well-known methods.
Abstract: MIMO-OFDM is a method adopted by new highspeed communications technologies such as IEEE802.11, IEEE 802.16 and 4G. Among the advantages of MIMO-OFDM, its ability to increase the transmission rate, and its adaptation to multipath channel with fading. Unfortunately the signals modulated by the OFDM technique generate high values of Peak-to-Average Power Ratio (PAPR). To solve this major drawback, several techniques have been proposed in literature. Among others, we find those that combine coding and companding. In this context we propose and study a new method based on μ-Law companding type and Polar Codes to reduce PAPR values in a MIMO-OFDM system. In order to evaluate the performances of our method in terms of PAPR and BER, several simulations are performed taking into consideration parameters related to coding and companding rates, and the number of sub carriers. The plotted curves show that the results are very significant; indeed, firstly our method achieves a gain of 8 dB in terms of PAPR by ensuring a good compromise in term of BER thanks to the use of the Polar Codes. Secondly our method operates with less complexity and outperforms the most well-known methods.

1 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed a new algorithm called BCB-OFDM based on Bose Chaudhuri Hocquenghem Codes (BCHs) and PI.
Abstract: Orthogonal Frequency Division Multiplexing (OFDM) has a great peak-to-average power ratio (PAPR). This will reduce the performance of the power amplifier (PA). Therefore, PAPR deteriorates the overall energy efficiency of an OFDM system. Peak Insertion (PI) is one of the most commonly used methods to reduce PAPR, it gives the best reduction in PAPR. Therefore, it causes a strong degradation in Bit Error Rate (BER). To solve this problem, we propose a new algorithm called BCB-OFDM based on Bose Chaudhuri Hocquenghem Codes (BCHs) and PI. BCB is implemented in OFDM system with Quadrature Amplitude Modulation (QAM) and two coding rates 1/2 and 1/4 over an Additive White Gaussian Noise (AWGN) channel. Simulation results show that the BCB is very interesting and achieve a good value in terms of PAPR reduction with keeping good performance compared with PI and normal OFDM. In addition, BCB algorithm is simple, robust, and leaves no requirement side information with more flexibility to choose between PAPR reduction and BER performances.

Cited by
More filters
Journal ArticleDOI
20 Jun 2020
TL;DR: In this article, wavelet transform transform (DWT) is used to replace Fourier transform (DFT) that used in conventional OFDM, later in this paper is termed as DFT-OFDM.
Abstract: Orthogonal Frequency Division Multiplexing (OFDM) is chosen as multiplexing techniques and broadly used in today’s radiocommunication environments to overcome spectrum insufficiency. With several superior advantages, however, OFDM is terribly affected by high peak to average power ratio (PAPR) due to offset frequency errors and local oscillator (LO) frequency synchronization errors. The high PAPR can cause nonlinear distortion, which outcomes in intermodulation and spectral leakage. This study aims to model the use of wavelet transform (discrete wavelet transform (DWT)) to replace Fourier transform (discrete Fourier transform (DFT)) that used in conventional OFDM, later in this paper is termed as DFT-OFDM. Clipping filtering techniques then applied to DWT-OFDM. The model was proposed to reduce PAPR in DFT-OFDM. The model was compared to DFT-OFDM using Matlab simulation method. The performance was evaluated using the Complementary Cumulative Distributive Function (CCDF) vs. PAPR. The results show that at PAPR 10 -3 for DFT-OFDM, it was produced PAPR of 10.6 dB whereas in DWT-OFDM, using Daubechies orde 7 (Daubechies7),  Symlet orde 7 (Symlet7), Coiflet orde 2 (Coiflet2), were reached PAPR 4.8 dB, PAPR 3.3 dB, PAPR 3 dB, respectively. It means Coiflet2 providing the best PAPR reduction among other orthogonal wavelets. By applied clipping filtering to wavelet Coiflet2, it was produced PAPR of 2.9 dB for classical clipping and 2.8 dB for deep clipping. It show that wavelet Coiflet2 with deep clipping provided the best PAPR.

2 citations

Journal ArticleDOI
TL;DR: Simulation has been done using MATLAB, evaluated PSD, spectral efficiency, BER performance and PAPR analysis of OFDM system, and the Selective Mapping approach is used in this study to lower the OFDM PAPr.
Abstract: A common standard modulation for several high data rate wireless communication systems is Orthogonal Frequency-Division Multiplexing (OFDM). It operates by splitting up large streams of data into several parallel streams with minimal data rates. Compared to single carrier modulation systems, OFDM offers various benefits. Some of these benefits are high transmission bit rates, great spectral efficiency, and sensitivity to frequency fading channels. However, there are drawbacks with OFDM. Among the major issues is the high Peak to Average Power Ratio (PAPR), due to which the system complexity increases. The Selective Mapping approach is used in this study to lower the OFDM PAPR. In this article, simulation has been done using MATLAB, evaluated PSD, spectral efficiency, BER performance and PAPR analysis of OFDM system.

2 citations

Proceedings ArticleDOI
06 Oct 2020
TL;DR: A simulation was done to evaluate the BER performance of the signal with the implementation of several PAPR reduction techniques, such as the wavelet transform, Partial Transmit Sequence (PTS) technique, and also the clipping technique.
Abstract: The implementation of FFT in OFDM system may provide many advantages, such as the bandwidth becomes more efficient and the signal performance over fading channel is better than single carrier signal. However, the PAPR of the signal is high and it can reach 10 dB, which is equivalent to a peak power that is 10 times higher than the average power. This way, the usage of FFT-based OFDM is not very efficient, especially in terms of power consumption at the transmitter. In this paper, a simulation was done to evaluate the BER performance of the signal with the implementation of several PAPR reduction techniques, such as the wavelet transform, Partial Transmit Sequence (PTS) technique, and also the clipping technique. The implementation was done with the 16 QAM and 64 QAM, and also the signal was sent through Rayleigh fading channel. The result shows that for 16 QAM, the best result is achieved by using db1 with PTS technique. With Eb/No value of 20 dB, the BER can be 10−3, which is 7 dB better than the normal FFT-based OFDM system. As for 64 QAM, the best result is achieved by the usage of normal db3 without PTS nor clipping technique. With Eb/No value of 24 dB, the BER can be 10−3, which is 4.5 dB better than FFT-based OFDM system.

1 citations

Journal ArticleDOI
01 Nov 2022-Optik
TL;DR: In this article , a modified Selective Mapping based PTS (SMPTS) method was proposed to enhance PAPR reduction and power amplifier efficiency in OFDM and MIMO (multiple inputs, multiple outputs)-OFDM methods through selective mapping based PTS method combined with power amplifier reduction methods.
Proceedings ArticleDOI
03 Aug 2021
TL;DR: In this paper, the effect of combining the Partial Transmit Sequence (PTS) with the Palm Date Leaf (PDL) clipping technique was evaluated with several modulation techniques, such as QPSK, 8 PSK, 16 PSK and 8-QAM.
Abstract: FFT, as the key concept in the OFDM system, produces a high PAPR value. Several techniques can be implemented to reduce it, such as the Palm Date Leaf clipping and the Partial Transmit Sequence. Previous researchers have evaluated each technique individually. This paper proposes to evaluate the PAPR value as the effect of combining the Partial Transmit Sequence (PTS) with the Palm Date Leaf (PDL) clipping technique. The evaluation is done with several modulation techniques, such as QPSK, 8-PSK, 16-PSK, 8-QAM, and 16-QAM. Since low PAPR performance is not advantageous if the signal’s BER value worsens, thus the evaluation also considers the BER performance. In this case, the Authors focus on the BER performance over the AWGN channel. The result shows that in all of the scenarios, the PTS technique could improve the signal’s BER and PAPR performance for low CR values such as 5 dB and 7 dB. Additionally, for higher CR values such as 10 dB and 20 dB, the BER performance is similar to the normal OFDM signal. Even so, it provides a consistent PAPR reduction of approximately 3 dB. Do note that the PAPR is evaluated at CCDF of 10−3. This way, the PTS technique always provides an improvement in signal BER performance. As for the PAPR performance, the PTS technique can improve all cases except for 8-QAM and 16-QAM signals with clipping technique at low clipping ratio such as 5 dB. However, the PTS technique still requires Side Information (SI), and it has high computational complexity.