scholarly journals Shaping code in conjunction with DCT for PAPR reduction in multicarrier system

Author(s):  
Younes Aimer ◽  
Boubakar Seddik Bouazza ◽  
Smail Bachir ◽  
Claude Duvanaud

AbstractNonlinear behavior and power efficiency of the Power Amplifier (PA) contradictorily depend on the input signal amplitude distribution. The transmitted signal in multi-carrier modulation exhibits high Peak-to-Average Power Ratio (PAPR) and large bandwidths, leading to the degradation of the radio link and additional generation out-of-band interferences, which degrade the quality of the transmission. Practical solutions exist, like a power back-off, but with unacceptable efficiency performances of the transmitter. This paper deals with efficiency and linearity improvement using a new PAPR reduction method based on the combination of Discrete Cosine Transform and shaping technique. The main principle is to determine an optimal coding scheme according to a trade-off between coding complexity and performance benefits in the presence of PA nonlinearities. Simulation and experimental results in the context of OFDM signal and using a 20 W–3.7 GHz Radio-Frequency Power Amplifier show an improvement on PAPR reduction of about 3.25 dB. Also, the communication criteria like Bit Error Rate and Error Vector Magnitude are improved by about one decade and a half and $$8\%$$ 8 % , respectively.

2021 ◽  
Author(s):  
Younes Aimer ◽  
Boubakar Seddik Bouazza ◽  
Smail Bachir ◽  
Claude Duvanaud

Abstract Nonlinear behavior and power efficiency of the Power Amplifier (PA) contradictorily depend on the input signal amplitude distribution. The transmitted signal in multi-carrier modulation exhibits high Peak-to-Average Power Ratio (PAPR) and large bandwidths, leading to the degradation of the radio link and additional generation out-of-band interferences, which degrade the quality of the transmission. Practical solutions exist, like a power back-off, but with unacceptable efficiency performances of the transmitter. This paper deals with efficiency and linearity improvement using a new PAPR reduction method based on the combination of Discrete Cosine Transform (DCT) and shaping technique. The main principle is to determine an optimal coding scheme according to a trade-off between coding complexity and performance benefits in the presence of PA non-linearities. Simulation and experimental results in the context of OFDM signal and using a 20W - 3.7GHz Radio-Frequency Power Amplifier (RF-PA) show an improvement on PAPR reduction of about 3.25dB. Also, the communication criteria like BER (Bit Error Rate) and EVM (Error Vector Magnitude) are improved by about one decade and a half and 8%, respectively.


2020 ◽  
Author(s):  
Younes Aimer ◽  
Boubakar Seddik Bouazza ◽  
Smail Bachir ◽  
Claude Duvanaud

Abstract Nonlinear behavior and power efficiency of the power amplifier (PA) depend in a contradictory way on the input signal amplitude distribution. The transmitted signal in multi-carrier modulation exhibits high peak-to-average power ratio (PAPR) and large bandwidths, leading to the degradation of the radio link and the generation of additional out-of-band interferences, which degrade the quality of the transmission. Practical solutions exist, like a power back-off, but with unacceptable cost-efficient conditions at the transmitter. This paper deals with efficiency improvement using a new PAPR reduction method based on the combination of Discrete Cosine Transform (DCT) and shaping technique. The main principle is to determine an optimal coding scheme according to a trade-off between efficiency performances and coding complexity. Simulation and experimental results in the context of OFDM Signal and in presence of a 20 W - 3,7 GHz RF-PA show an improvement on PAPR reduction of about 3,25 dB. Also, the communication criteria like BER (Bit Error Rate) and EVM (Error Vector Magnitude) are improved of about 2 decades and 8 %, respectively.


2014 ◽  
Vol 596 ◽  
pp. 794-798
Author(s):  
Rui Zhang ◽  
Zhi Bin Zeng

The main disadvantage of multicarrier system is the high peak-to-average power ratio which can easily result in significant cut-the-top distortion of power amplifier. However, the power efficiency of power amplifier will be reduced by power back-off technology. Therefore, crest factor reduction is important in reducing the peak-to-average power ratio of multicarrier system and improving the efficiency of power amplifier. The peak-to-average power ratio can be effectively reduced with small distortion by the algorithm of crest factor reduction based on peak cancellation. And the performance of peak-to-average power ratio is better with the same error vector magnitude.


2013 ◽  
Vol 380-384 ◽  
pp. 3538-3541
Author(s):  
Qian Hui Liu ◽  
Jian Wang

High peak-to-average power ratio (PAPR) is one of the main disadvantages for OFDM signals, which will always result in low power efficiency of power amplifier. The peak cancellation method is a powerful PAPR reduction technique. In this paper, the advanced peak cancellation implement method (APC) is proposed for OFDM signals. Extensive simulations demonstrate that in comparison with the conversational peak cancellation implement method, the APC is more suitable for OFDM signals due to less iteration and comparative performance.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2831
Author(s):  
Teng Wang ◽  
Wantao Li ◽  
Roberto Quaglia ◽  
Pere L. Gilabert

This paper presents an auto-tuning approach for dual-input power amplifiers using a combination of global optimisation search algorithms and adaptive linearisation in the optimisation of a multiple-input power amplifier. The objective is to exploit the extra degrees of freedom provided by dual-input topologies to enhance the power efficiency figures along wide signal bandwidths and high peak-to-average power ratio values, while being compliant with the linearity requirements. By using heuristic search global optimisation algorithms, such as the simulated annealing or the adaptive Lipschitz Optimisation, it is possible to find the best parameter configuration for PA biasing, signal calibration, and digital predistortion linearisation to help mitigating the inherent trade-off between linearity and power efficiency. Experimental results using a load-modulated balanced amplifier as device-under-test showed that after properly tuning the selected free-parameters it was possible to maximise the power efficiency when considering long-term evolution signals with different bandwidths. For example, a carrier aggregated a long-term evolution signal with up to 200 MHz instantaneous bandwidth and a peak-to-average power ratio greater than 10 dB, and was amplified with a mean output power around 33 dBm and 22.2% of mean power efficiency while meeting the in-band (error vector magnitude lower than 1%) and out-of-band (adjacent channel leakage ratio lower than −45 dBc) linearity requirements.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1410
Author(s):  
Mohamed Mounir ◽  
Mohamed B. El_Mashade ◽  
Salah Berra ◽  
Gurjot Singh Gaba ◽  
Mehedi Masud

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.


2021 ◽  
Author(s):  
Srinivas Ramavath ◽  
Umesh Chandra Samal

Abstract In this paper, two new companders are designed to reduce the ratio of peak to average power (PAPR) experienced by filter bank multicarrier (FBMC) signals. Specifically, the compander basic model is generalized, which alter the distributed FBMC signal amplitude peak. The proposed companders design approach provides better performance in terms of reducing the PAPR, Bit Error Rate (BER) and phase error degradation over the previously existing compander schemes. Many PAPR reduction approaches, such as the µ-law companding technique, are also available. It results in the formation of spectrum side lobes, although the proposed techniques result in a spectrum with fewer side lobes. The theoretical analysis of linear compander and expander transform for a few specific parameters are derived and analyzed. The suggested linear companding technique is analytically analysed using simulations to show that it efficiently decreases the high peaks in the FBMC system.


2021 ◽  
Vol 2128 (1) ◽  
pp. 012004
Author(s):  
Sahar M. Alrabeiy ◽  
Sameh A. Fathy ◽  
Safa M. Gasser ◽  
Mohamed S. El-Mahallawy

Abstract One of the most promising 5G waveform candidates is the universal-filtered multicarrier system (UFMC). The UFMC system reduces the out-of-band (OoB) emission, bringing about higher spectral efficiency. This is assumed to reach robustness against frequency offset and low latency. Although, as aforementioned, the UFMC system offers many advantages, it lacks high peak-to-average power ratio (PAPR) as a multicarrier transmission technique. This research paper tackles two approaches; firstly, RCS, by developing a simulated conventional SLM system, with modifications to generate the same number of waveforms, while using fewer UFMC modulators. Secondly, by developing a simulated conventional SLM system, with modifications using the same number of modulators to generate more waveforms that would be generated in the conventional scheme. The two sets of results from the proposed M-SLM scheme are compared to each other, and to other PAPR reduction schemes using OFDM and UFMC. To reduce PAPR in UFMC systems, (M-SLM) scheme with low complexity is proposed. The essence of the proposed M-SLM scheme is represented in making use of the cyclically shifting process and FMC modulator’s linearity property. The proposed M-SLM scheme uses Um UFMC modulators to produce Uw alternative UFMC waveforms, where Uw = Um (2Um − 1). As a result, drawing a comparison with existing SLM based PAPR reduction schemes for UFMC systems; the proposed M-SLM scheme's computational complexity is reduced. Finally, there is a comparison between the proposed M-SLM scheme and the schemes there in the literature according to PAPR reduction ability.


Author(s):  
Zainab M Abid ◽  
Awatif A Jaffaar ◽  
Suha Q Hadi

<p>A special form of multicarrier modulation is Orthogonal Frequency Division Multiplexing (OFDM) which is offer high spectral efficiency for high speed data transmission through multipath fading channels. Many advantages can be achieved by using OFDM in addition to spectral efficiency like its robustness against intersymbol interference and multipath effect. One of a major drawback of OFDM is high Peak-to-Average Power Ratio (PAPR) of the transmitted signal which leads to a distortion in the power amplifier and causes decreasing the efficiency of power amplifier. To reduce PAPR of OFDM signal many of promising solutions have been proposed and implemented. In this paper, a joint Low Density Parity Check code (LDPC), Discrete Cosine Transform (DCT) and μ-law companding is proposed to reduce PAPR of OFDM signal at transmitter. Comparison of these PAPR reduction techniques is done based on CCDF performance of the system.</p>


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