scholarly journals Wavelet Based Multicarrier Modulation (MCM) Systems: PAPR Analysis

2020 ◽  
Author(s):  
Jamaluddin Zakaria ◽  
Mohd Fadzli Mohd Salleh
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Wavelet Packet ◽  
Additive White Gaussian Noise ◽  
Average Power ◽  
Poor Performance ◽  
Multicarrier Modulation ◽  
Bandwidth Efficiency ◽  
High Power Amplifier ◽  
Non Stationary Signal ◽  
Orthogonal Modulation

Orthogonal frequency division multiplexing (OFDM) is a prominent system in transmitting multicarrier modulation (MCM) signals over selective fading channel. The system offers to attain a higher degree of bandwidth efficiency, higher data transmission, and robust to narrowband frequency interference. However, it incurs a high peak-to-average power ratio (PAPR) where the signals work in the nonlinear region of the high-power amplifier (HPA) results in poor performance. Besides, an attractive dynamic wavelet analysis and its derivatives such as wavelet packet transform (WPT) demonstrates almost the same criteria as the OFDM in MCM system. Wavelet surpasses Fourier based analysis by inherent flexibility in terms of windows function for non-stationary signal. In wavelet-based MCM systems (wavelet OFDM (WOFDM) and Wavelet packet OFDM (WP-OFDM)), the constructed orthogonal modulation signals behaves similar to the fast Fourier transform (FFT) does in the conventional OFDM (C-OFDM) system. With no cyclic prefix (CP) need to be applied, these orthogonal signals hold higher bandwidth efficiency. Hence, this chapter presents a comprehensive study on the manipulation of specified parameters using WP-OFDM, WOFDM and C-OFDM signals together with various wavelets under the additive white Gaussian noise (AWGN) channel.

scholarly journals A Novel Hybrid Precoding-Companding Technique for Peak-to-Average Power Ratio Reduction in 5G and beyond

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1410
Author(s):  
Mohamed Mounir ◽  
Mohamed B. El_Mashade ◽  
Salah Berra ◽  
Gurjot Singh Gaba ◽  
Mehedi Masud
Keyword(s):  
Computational Complexity ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Average Power ◽  
Papr Reduction ◽  
Power Ratio ◽  
Error Vector Magnitude ◽  
Hybrid Precoding ◽  
High Power Amplifier ◽  
Reduction Techniques

Several high-speed wireless systems use Orthogonal Frequency Division Multiplexing (OFDM) due to its advantages. 5G has adopted OFDM and is expected to be considered beyond 5G (B5G). Meanwhile, OFDM has a high Peak-to-Average Power Ratio (PAPR) problem. Hybridization between two PAPR reduction techniques gains the two techniques’ advantages. Hybrid precoding-companding techniques are attractive as they require small computational complexity to achieve high PAPR reduction gain. Many precoding-companding techniques were introduced to increasing the PAPR reduction gain. However, reducing Bit Error Rate (BER) and out-of-band (OOB) radiation are more significant than increasing PAPR reduction gain. This paper proposes a new precoding-companding technique to better reduce the BER and OOB radiation than previous precoding-companding techniques. Results showed that the proposed technique outperforms all previous precoding-companding techniques in BER enhancement and OOB radiation reduction. The proposed technique reduces the Error Vector Magnitude (EVM) by 15 dB compared with 10 dB for the best previous technique. Additionally, the proposed technique increases high power amplifier efficiency (HPA) by 11.4%, while the best previous technique increased HPA efficiency by 9.8%. Moreover, our proposal achieves PAPR reduction gain better than the most known powerful PAPR reduction technique with a 99% reduction in required computational complexity.

scholarly journals Discrete Cosine Transform Matrix Based SLM Algorithm for OFDM with Diminished PAPR for M-PSK over Different Subcarriers

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Prabal Gupta ◽  
Rajiv Kumar Singh ◽  
H. Pal Thethi ◽  
Balpreet Singh ◽  
Santosh Kumar Nanda
Keyword(s):  
Discrete Cosine Transform ◽  
Orthogonal Frequency Division Multiplexing ◽  
Side Information ◽  
Average Power ◽  
Ofdm Systems ◽  
Matlab Simulation ◽  
Cosine Transform ◽  
High Power Amplifier ◽  
Definite Structure ◽  
Transform Matrix

Orthogonal frequency division multiplexing (OFDM) is the highly spectrally well-organized method that has the difficulty of excessive peak power to average power ratio (PAPR), which ultimately imposes constraints on the high-power amplifier. Many practices have been projected to lessen PAPR of the OFDM systems. Amongst all the practices, the selected mapping (SLM) method has drawn more attention because of distortion-less behaviour. This technique uses unique phase sequences. It has been learnt that phase formation for SLM is very tedious. In the proposed work, the SLM method has been used, but phase arrangement formation is based on the usage of discrete cosine transform (DCT) matrix. In this proposed work, discrete cosine transform matrix has been chosen based on the requirement of optimization so that the arrangement with lowest PAPR can be nominated for the transmission. MATLAB simulation depicts that the remarkable gain is achieved as compared with the existing technique. In the proposed work, scheming of phase sequences are very informal due to the use of a DCT matrix which has a definite structure and can be generated at the receiver side with the help of side information of the phases and communicated from the transmitter to the receiver.

New Tone Reservation Technique for Peak to Average Power Ratio Reduction

Frequenz ◽  
2014 ◽  
Vol 68 (9-10) ◽  
Author(s):  
Joachim Wilharm ◽  
Hermann Rohling
Keyword(s):  
Computational Complexity ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Peak Position ◽  
High Power Amplifier ◽  
Constant Envelope ◽  
Tone Reservation ◽  
Power Ratio Reduction ◽  
Ratio Reduction ◽  
High Computational Complexity

AbstractIn Orthogonal Frequency Division Multiplexing (OFDM) the transmit signals have a highly fluctuating, non-constant envelope which is a technical challenge for the High Power Amplifier (HPA). Without any signal processing procedures the amplitude peaks of the transmit signal will be clipped by the HPA resulting in out-ofband radiation and in bit error rate (BER) performance degradation. The classical Tone Reservation (TR) technique calculates a correction signal in an iterative way to reduce the amplitude peaks. However this step leads to a high computational complexity. Therefore, in this paper an alternative TR technique is proposed. In this case a predefined signal pattern is shifted to any peak position inside the transmit signal and reduces thereby all amplitude peaks. This new procedure is able to outperform the classical TR technique and has a much lower computational complexity.

scholarly journals Analysis of the PAPR Behavior of the OFDM Passband Signal

2019 ◽  
Author(s):  
Frank Andrés Eras ◽  
Italo Alexander Carreño ◽  
Thomás Borja ◽  
Diego Javier Reinoso ◽  
Luis Urquiza-Aguiar ◽  
...  
Keyword(s):  
Bit Error Rate ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Wireless Communication Systems ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm System ◽  
High Power Amplifier

Orthogonal Frequency Division Multiplexing (OFDM) is a technique widely used in today's wireless communication systems due to its ability to combat the effects of multi-path in the signal. However, one of the main limitations of the use of OFDM is its high Peak-to-Average Power Ratio (PAPR), which reduces the efficiency of the OFDM system. The effects of PAPR can produce both out-of-band and in-band radiation, which degrades the signal by increasing the bit error rate (BER), this occurs in both baseband and bandpass sginals. In this document the effect of the PAPR in a OFDM passband signal is analyzed considering the implementation of a High Power Amplifier (HPA) and the Simple Amplitude Predistortion-Orthogonal Pilot Sequences (OPS-SAP) scheme to reduce the PAPR.

scholarly journals Companding Technique for Reducing Peak-to-Average Power Ratio in OFDM Linear Coded Systems

2012 ◽  
pp. 160-165
Author(s):  
B. Ragini ◽  
M. Sushanth Babu ◽  
K. Kishan Rao
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Additive White Gaussian Noise ◽  
Average Power ◽  
Power Ratio ◽  
Frequency Division ◽  
Channel Fading ◽  
Reduction Techniques ◽  
Coded Systems ◽  
Impulse Interference ◽  
Very High

Orthogonal Frequency division multiplexing (OFDM) is a very attractive technique in wireless communications which provides robustness to channel fading and immunity to impulse interference. Despite of its advantages, one of the major drawbacks of OFDM system is very high peak-to-average power ratio (PAPR). Among the various PAPR reduction techniques, companding appears attractive for its simplicity and effectiveness. In this paper novel Low density parity check (LDPC) encoded new companding technique is proposed which offers improved bit error rate, minimizes out-of-band interference and reduce PAPR effectively. Simulation results illustrates the performance of the system under Additive White Gaussian Noise (AWGN) and further evaluation is done for comparing the proposed companding technique with previous techniques.

scholarly journals CE-OFDM-CDMA Phase Modulation for 5G System

2021 ◽  
Vol 6 (4) ◽  
pp. 1100-1114
Author(s):  
Jamal Mestoui ◽  
Mohammed El Ghzaoui ◽  
Serghini Elaage ◽  
Abdelmounim Hmamou ◽  
Jaouad Foshi
Keyword(s):  
Phase Modulation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Additive White Gaussian Noise ◽  
Minimum Mean Square Error ◽  
Average Power ◽  
Multipath Fading ◽  
Modulation Scheme ◽  
Time Frequency ◽  
High Spectral Efficiency ◽  
Code Division Multiple

In the present work, we propose a novel modulation scheme for 5G wireless communication system. Our contribution is to combine PM-OFDM (Phase Modulation Orthogonal Frequency Division Multiplexing) and CDMA (Code Division Multiple Access) to exploit their distinctive advantages. On the one hand, PM-OFDM is an effective technique to combat multipath fading effects. On the other hand, CDMA can serve multiple users who are using the same resources of time/frequency. The aim is to make a combination of PM-OFDM and CDMA techniques. In this paper, the OFDM-CDMA scheme and its PAPR (Peak-to-Average Power Ratio) statistics are reviewed. In this paper, the proposed scheme PM-OFDM-CDMA is described and its performances in terms of PAPR, power spectral density, and BER (Bit Error Rate) are analyzed. Moreover, MMSE (Minimum Mean Square Error) equalizer is used to avoid multipath and noise effects simultaneously. The simulation through AWGN (Additive white Gaussian noise) and Rayleigh channels is performed using MATLAB. From the simulation results, we observed that PM-OFDM-CDMA is an efficient technique in terms of energy consumption (PAPR = 0dB). Besides, CE-OFDM-CDMA offers high spectral efficiency with low BER due to its low PAPR. In CE-OFDM-CDMA method, the shape of the spectrum varies according to the value of the modulation index h. The band occupied by the spectrum increases with the value of h. Therefore, CE-OFDM-CDMA could be considered as a suitable technique for 5G applications.

A Hybrid Method to Reduce PAPR of OFDM to Support 5G Technology

2021 ◽  
pp. 241-257
Author(s):  
Bhavana D. ◽  
Adada Neelothpala ◽  
Pamidimukkala Kalpana
Keyword(s):  
Power Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Multimedia Data ◽  
High Peak ◽  
Modulation Scheme ◽  
Power Ratio ◽  
Digital Subscriber Line ◽  
Asymmetric Digital Subscriber Line ◽  
High Power Amplifier

The orthogonal frequency division multiplexing (OFDM) is a multicarrier modulation scheme used for the transfer of multimedia data. Well-known systems like ADSL (asymmetric digital subscriber line) internet, wireless local area networks (LANs), long-term evolution (LTE), and 5G technologies use OFDM. The major limitation of OFDM is the high peak-to-average power ratio (PAPR). High PAPR lowers the power efficiency, thus impeding the implementation of OFDM. The PAPR problem is more significant in an uplink. A high peak-to-average power ratio (PAPR) occurs due to large envelope fluctuations in OFDM signal and requires a highly linear high-power amplifier (HPA). Power amplifiers with a large linear range are expensive, bulky, and difficult to manufacture. In order to reduce the PAPR, a hybrid technique is proposed in this chapter with repeated clipping and filtering (RCF) and precoding techniques. The proposed method is improving the PAPR as well as BER. Five types of pre-coding techniques are used and then compared with each other.

scholarly journals PAPR reduction in LTE network using both peak windowing and clipping techniques

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Richard Musabe ◽  
Mafrebo B. Lionel ◽  
Victoire Mugongo Ushindi ◽  
Mugisha Atupenda ◽  
James Ntaganda ◽  
...  
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Additive White Gaussian Noise ◽  
Research Work ◽  
Average Power ◽  
Threshold Level ◽  
Papr Reduction ◽  
Major Drawback ◽  
Reduction Techniques ◽  
Secured Data

AbstractMulticarrier technique orthogonal frequency division multiplexing (OFDM) modulation is a solution to provide high-speed and secured data transmission requirement in 4G technologies. Peak-to-average power ratio (PAPR) is one major drawback in OFDM system. Researches described several PAPR reduction techniques, notably peak windowing and clipping. The aim of this paper is to use these techniques to reduce PAPR. The research work describes clipping and windowing techniques such as quadratic amplitude modulation (QAM) and additive white Gaussian noise (AWGN) as channel condition. The simulation results show that in those techniques with clipping threshold level of 0.7, there is a reduction of PAPR of 8 dB, and the reduction of PAPR for the peak windowing when considering Kaiser window is about 11 dB.

scholarly journals A Novel GFDM Waveform Design Based on Cascaded WHT-LWT Transform for the Beyond 5G Wireless Communications

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1831
Author(s):  
Meryem Maraş ◽  
Elif Nur Ayvaz ◽  
Meltem Gömeç ◽  
Asuman Savaşcıhabeş ◽  
Ali Özen
Keyword(s):  
Fading Channels ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Additive White Gaussian Noise ◽  
Average Power ◽  
Hadamard Transform ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Simulation Results ◽  
Walsh Hadamard Transform

In this paper, a new WHT-LWT-GFDM waveform obtained by combining Walsh–Hadamard Transform (WHT), Lifting Wavelet Transform (LWT), and Generalized Frequency Division Multiplexing (GFDM) is presented for use in next-generation wireless communication systems. The proposed approach meets the requirement of 5th-generation (5G) and beyond communication schemes in terms of low latency, low peak-to-average-power ratio (PAPR), and low bit-error rate (BER). To verify the performance of the presented waveform, PAPR and BER simulation results were obtained in additive white Gaussian noise (AWGN) and flat Rayleigh fading channels, and the performance of the proposed system was compared with conventional Orthogonal Frequency Division Multiplexing (OFDM), GFDM, and Walsh–Hadamard transform-based GFDM (WHT-GFDM). Simulation results show that the proposed waveform achieves the best BER and PAPR performances and it provides considerable performance gains over the conventional waveforms.

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