scholarly journals THE REDUCTION OF PAPR IN OFDM BY USING NEW COMPANDING TRANSFORM

Author(s):  
T. NAGARAJU ◽  
K. RAMANAIDU

The main drawback of the OFDM is its high peak to average power ratio(PAPR).There are several PAPR reduction techniques. Among the various PAPR reduction techniques, companding transform is attractive for its simplicity and effectiveness. This paper proposes a new companding algorithm. The proposed algorithm offers an improved bit error rate and minimized out-of-band interference while reducing PAPR effectively, compared with the others. Theoretical analysis and numerical simulation are presented.

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.


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.


Author(s):  
PRITANJALI KUMARI ◽  
US TRIAR

Orthogonal Frequency Division Multiplexing (OFDM), widely used in digital wireless communication, has a major drawback of high Peak to Average Power Ratio (PAPR). A reduced complexity partial transmit sequence (PTS) scheme has been proposed to solve high peak to average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) system. In the proposed PTS scheme, a function is generated by summing the power of time domain samples at time ‘n’ in each sub blocks, known as “Hn”.Only those samples, having Hn greater than or equal to a preset threshold value (αT) are used for peak power calculation during the process of selecting a candidate signal with the lowest PAPR for transmission. As compared to conventional PTS scheme, the proposed scheme achieves almost the same PAPR reduction performance with much lower computational complexity.


2014 ◽  
Vol 635-637 ◽  
pp. 1081-1085
Author(s):  
Xin Xin Sha ◽  
Jian Zhou ◽  
Yuan Xue Song

OFDM is a key modulation and multiplexing technique. The basic system structure of OFDM is introduced firstly. This paper chose appropriate implementation schemes for channel coding, PAPR(Peak To Average Power Ratio) reducing and synchronization of the OFDM system based on the minimum BER(Bit Error Rate). Finally, the paper realized the simulation and got the BER in different SNR(Signal To Noise Ratio) in the matlab environment .


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.


In the transmitted signal, the high peak-toaverage power ratio (PAPR) is the real disadvantage of multiple input, multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems. Among different PAPR reduction techniques, selected mapping (SLM) is a famous strategy that accomplishes good PAPR reduction performance without signal distortion. Likewise, Partial transmit sequence (PTS) is additionally solitary of the successful techniques to decrease the PAPR in OFDM. Though, result an optimal segment issue in PTS system is measured to exist a critical concern. To progress the existing PAPR reduction techniques, we have incorporated ideal SLM and PTS based PAPR reduction strategy in parallel. By utilizing, the OGWO algorithm; the transmit succession was chosen with least PAPR above all communication antennas. The proposed PAPR reduction approach is applied independently on each transmitted antenna, and so the PAPR can be extremely reduced. Moreover, the OGWO optimization based PAPR reduction technique will provide better performance and it was been promoted as an uncomplicated way for PAPR reduction. The proposed approach will be analyzed with various novel PAPR reduction schemes to show the effectiveness.


2011 ◽  
Vol 145 ◽  
pp. 489-493
Author(s):  
H.A. Hamada ◽  
Usama S. Mohammed ◽  
Moon Kyou Song

Orthogonal Frequency Division Multiplexing (OFDM) technique is becoming the chosen modulation technique for wireless communications. OFDM can provide large data rates with sufficient robustness to radio channel impairments. There are two main drawbacks with OFDM, the peak to average power ratio and its sensitivity to frequency errors. The signal peak to average power ratio reduction solution play an important role to improve performance of OFDM that peak occurs after symbols fed to FFT to produce time domain signal, adding signals up coherently. In This paper we proposes technique to reduce the PAPR using Huffman coding combined with selective interleaver as distortion less scrambling technique. We utilize the amount saved in the total bit rate by the Huffman coding to send the information of the selected interleaver and encoding table for accurate decoding at the receiver without reducing the effective throughput. Performed computer simulations have shown that the proposed scheme outperform the performance of most of the recent PAPR reduction techniques in most cases. By using this method 2.63 dB PAPR reduction is achieved.


Most of the wireless standards used these days, heavily rely on Orthogonal Frequency Division Multiplexing (OFDM). Peak to Average Power Ratio (PAPR) is one of the known key acknowledged confines of OFDM. Reduced PAPR at OFDM transmitter helps power amplifier to operate in stable mode and reduction in complexity of digital to analog converter (DAC). Several PAPR reduction techniques have been evolved from different principles such as signal scrambling techniques, such as Partial Transmit Sequence (PTS), signal distortion techniques such as Clipping, etc. Reducing PAPR degrades bit error rate (BER) or computational complexity. PTS is one of the best methods of PAPR reduction. There is large scope of betterment of PTS to get a best PAPR reduction technique. In this paper we have concentrated on PTS scheme by exploring PTS and its variants evolved over a period of time. We proposed a novel PTS with best performance balancing PAPR and BER performance. Design and development of scheme is done using a graphical programming environment LabVIEW (Laboratory Virtual Instrumentation Engineering Workbench) and real time environment validation is done with software defined radio – NIUSRP2922, which is National Instruments Universal Software Radio Peripheral. The paper has three sections in first section, Introduction, the OFDM fundamentals and PAPR are defined in design perspective, in second section conventional and proposed PTS schemes have been explained. The third section consists of result and conclusion


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