scholarly journals Low-Complexity Blind Selected Mapping Scheme for Peak-to-Average Power Ratio Reduction in Orthogonal Frequency-Division Multiplexing Systems

Information ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 220 ◽  
Author(s):  
Yujie Xia ◽  
Jinwei Ji
Keyword(s):  
Time Domain ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Low Complexity ◽  
Power Ratio ◽  
Frequency Division ◽  
Phase Rotation ◽  
Rotation Vectors ◽  
The Time Domain ◽  
Ofdm Signals

Orthogonal frequency-division multiplexing (OFDM) is an attractive multicarrier technique for the simplicity of equalization and high data throughput. However, the transmitted OFDM signal has a very high peak-to-average power ratio (PAPR), which severely degrades the performance of practical OFDM systems and reduces the efficiency of high-power amplifiers (HPA). The selected mapping (SLM) scheme is an effective PAPR reduction method of OFDM signals. However, this approach usually requires side information (SI) transmission, which increases the difficulty of the hardware implementation with high complexity and reduces the data transmission rate. In this paper, based on designing phase rotation vectors in the time domain, a novel blind SLM method with low complexity is proposed to reduce the PAPR of OFDM signals. At the transmitter, the proposed method properly designs the phase rotation vectors in the time domain, which can be considered as an equivalent wireless channel without SI transmission. At the receiver, the effect of phase rotation vectors can be removed by the conventional channel estimation method, and the data demodulation processing can be easily performed by the frequency domain equalization. Simulation results show that the proposed scheme can achieve low complexity in PAPR reduction and has great robustness in bit error rate (BER) performance compared to the other low-complexity SLM PAPR schemes.

scholarly journals PAPR Reduction of OFDM Signals by Novel Global Harmony Search in PTS Scheme

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Hojjat Salehinejad ◽  
Siamak Talebi
Keyword(s):  
Smart Grids ◽  
Orthogonal Frequency Division Multiplexing ◽  
Signal Transmission ◽  
Harmony Search ◽  
Average Power ◽  
Wind Farms ◽  
Papr Reduction ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm Signals

The orthogonal frequency division multiplexing (OFDM) modulation technique is one of the key strategies for multiuser signal transmission especially in smart grids and wind farms. This paper introduces an approach for peak-to-average power ratio (PAPR) reduction of such signals based on novel global harmony search (NGHS) and partial transmit sequence (PTS) schemes. In PTS technique, the data block to be transmitted is partitioned into disjoint subblocks, which are combined using phase factors to minimize PAPR. The PTS requires an exhaustive search over all combinations of allowed phase factors. Therefore, with respect to the fast implementation and simplicity of NGHS technique, we could achieve significant reduction of PAPR.

scholarly journals A low complexity partial transmit sequence approach based on hybrid segmentation scheme

2020 ◽  
Vol 9 (6) ◽  
pp. 2371-2379
Author(s):  
Ali Hussein Fadel ◽  
Hasanain H. Razzaq ◽  
Salama A. Mostafa
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Low Complexity ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Wave Shape ◽  
Data Sequence ◽  
Practical Applications ◽  
Phase Rotation ◽  
Hybrid Segmentation

The partial transmit sequences (PTS) is regarded as a promising scheme for inhibiting ‎the high peak-to-average power ratio (PAPR) problem in the orthogonal frequency division ‎multiplexing (OFDM) systems. The PTS scheme relies on partitioning the ‎data sequence into subsets and weighting these subsets by a group of the phase rotation ‎factors. Although the PTS can efficiently reduce the high PAPR value, a great ‎computational complexity (CC) level restricts the utilization of the PTS scheme in practical ‎applications. In PTS, there are three common types of segmentation schemes; ‎interleaving (IL-PTS), pseudo-random (PR-PTS), and adjacent (Ad-PTS) schemes. This ‎paper presents a new algorithm named hybrid pseudo-random and interleaving cosine wave shape ‎‎(H-PRC-PTS) by combining the PR-PTS scheme and the symmetrical ‎interleaving cosine wave shape (S-IL-C-PTS) scheme which was proposed in our previous ‎work. The results indicate that the suggested algorithms can ‎diminish the PAPR value like the PR-PTS scheme, whereas the CC level is reduced significantly.

scholarly journals A REVIEW OF NOVEL APPROACH FOR REDUCTION IN SUB CARRIER PEAK TO AVERAGE POWER RATIO IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING

2020 ◽  
Vol 5 (2) ◽  
pp. 114-122
Author(s):  
Manju Sangar ◽  
Professor Brijendra Mishra ◽  
Professor Bhupendra Verma
Keyword(s):  
High Power ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
High Mobility ◽  
Low Complexity ◽  
Multimedia Data ◽  
Papr Reduction ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division

In last few decades the demand for multimedia data services has grown up fastly. One of the most promising multicarrier system, Orthogonal Frequency Division Multiplexing (OFDM) allow large number of capacity the number of subcarriers, high data rates and ubiquitous coverage with high mobility. But OFDM is extensively affected by peak to average power ratio (PAPR). Unfortunately, the high PAPR inherent to OFDM signal envelopes will frequently drive high power amplifiers (HPAs) which are operate in the nonlinear region. The nonlinearity of the High Power Amplifier exhibits phase and amplitude distortions, which causes loss of orthogonality between the subcarriers; also (ICI) is introduced in the source signal. This dissertation is basically focused on PAPR reduction in OFDM system and measuring BER in different Modulation Technique. In PAPR reduction Signal companding methods have low complication, high distortion and spectral properties; however, we have limited PAPR reduction capabilities. Partial transmit sequences (PTS) and selected mapping (SLM), have also been considered for PAPR reduction. Such kind of techniques are very efficient and distortion less, Also the SLM is very good technique to the PAPR problem in single carrier system. This method has low complexity as well as it is data independent. In this paper, we are describing a combine technique of SLM and PTS to minimize the PAPR. In PTS scheme, number of sub blocks increases; the IFFT block to be performed for sub blocks also increases. Simulation results have shown that the reductions of PAPR of proposed scheme is more than PTS and SLM methods as well as the difficulty reduced considerably.

Evaluating and Reducing the Envelope Fluctuations of OFDM Signals Based on Distortion Prediction

Frequenz ◽  
2017 ◽  
Vol 71 (1-2) ◽  
pp. 73-81
Author(s):  
Xiangyin Zhang ◽  
Xiaodong Zhu ◽  
Youxi Tang
Keyword(s):  
System Performance ◽  
Orthogonal Frequency Division Multiplexing ◽  
Nonlinear Distortion ◽  
Average Power ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Selective Mapping ◽  
Mapping Scheme ◽  
Ofdm Signals

Abstract Orthogonal frequency division multiplexing (OFDM) signals with large envelope fluctuations are prone to be affected by power amplifier (PA), resulting in degradation of system performance. Peak-to-average power ratio (PAPR) and cubic metric (CM) are commonly used as the reduction criteria of envelope fluctuations of OFDM signals. However, our analysis shows that minimizing the PAPR or CM does not necessarily mean the optimization of system performance, since both metrics are inadequate to quantify the distortion in nonlinear OFDM transmission. In this paper, we fully discuss the effects of PA nonlinearity on OFDM signals and propose a new metric called distortion component metric (DCM), which is closely related to the nonlinear distortion caused by the PA. We compare the system performance when several metrics are respectively used as the reduction criterion for the selective mapping scheme. It is shown that in the presence of memoryless or memory PA, the usage of DCM can provide better inband and out-of-band performance than PAPR and CM.

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