Sliding the SLM-technique to Reduce the Non-Linear Distortion in OFDM Systems

Abstract-Although the orthogonal frequency division multiplexing system (OFDM) is widely used in high-speed data rate wire and wireless environment, the peak-to-average-powerratio (PAPR) is one of its major obstacles for the real applications. The high PAPR value leads some devices of the OFDM system such as power amplifiers and analog to digital converters to work out of band of these devices. Thus the system efficiency is degraded. Many techniques have been proposed to overcome the high PAPR in OFDM systems such as partial transmit sequences (PTS), selected mapping and interleaving technique. PTS is considered as one of the effective PAPR reduction methods; this scheme depends on segmentation of the input data into several subblocks and then combined again. The three well-known segmentation schemes are pseudo-random, adjacent and interleaving; each scheme has PAPR reduction performance, and computational complexity differs from one to another. In this paper, five types of segmentation schemes are proposed to improve the PAPR reduction execution including sine and cosine shape as well as hybrid interleaving and adjacent schemes in new approaches. From the simulation results, the proposed methods can achieve PAPR reduction performance greater than that of the adjacent and interleaving partition schemes, without increasing the computational complexity of the system. Moreover, the enhanced schemes can realize better PAPR performance with any number of subcarriers.

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“…The PAPR is the ratio of the maximum peak power signal to average power of OFDM signal, which can be written as [29] …”

Section: Ofdm Systemmentioning

confidence: 99%

An Enhanced Partial Transmit Sequence Segmentation Schemes to Reduce the PAPR in OFDM Systems

Al‐Jawhar¹,

Shah²,

Taher³

et al. 2016

ijacsa

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“…Unlike CSLM, our method uses the time-domain data vector to reduce the PAPR and the computational complexity, and the side information will be reduced dramatically; therefore, it is called post-IFFT-modified SLM (PI-MSLM). PI-MSLM uses only one PRV [35] after the IFFT block of the original OFDM system. Moreover, the length of the PRV is a small part of the OFDM total length, N , such that it is only w = N /r where r < N where r is the length control of the PRV.…”

Section: Proposed Approachmentioning

confidence: 99%

“…Moreover, the best PRVs should have phases of 0 and π with equal probabilities [41]. Taher et al [35] introduced a technique that slides a constant PRV selected from Hadamard sequences over the data sequence; the PAPR, the computational complexity, and the side information were reduced dramatically. A technique that enabled the receiver to recover the data without side information was introduced in [1]; in other words, the PRVs have the ability to make the receiver remove the side information, the cost of which was paid in terms of the degradation in the BER performance because this method is applicable to small constellation mappings.…”

Section: Introductionmentioning

confidence: 99%

Post-IFFT-Modified Selected Mapping to Reduce the PAPR of an OFDM System

Taher

Singh

Ismail

et al. 2014

Circuits Syst Signal Process

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Orthogonal frequency-division multiplexing is now one of the most important modulation techniques due to its advantages. Despite its ability to overcome the equalization problem, multipath fading channels, and other issues, this system has a serious problem concerning the high output peaks with respect to the average power, which is called the peak-to-average power ratio (PAPR). Selected mapping (SLM), partial transmitted sequence, and amplitude clipping and filtering are some efficient methods to reduce the PAPR. In a previous work, we slid a single-phase rotation vector Circuits Syst Signal Process on the data sequence in the frequency domain to reduce the PAPR and the complexity compared to the conventional SLM. In this paper, we present a novel method that utilizes the same approach of our previous work, but it processes the data after the inverse fast Fourier transform block (time-domain operations) using a modified version of the SLM scheme, which has less computational complexity than the conventional one. The mathematical derivations and the simulation results show that the PAPR, the computational complexity, and the side information were reduced significantly by the proposed method.

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“…Many techniques have been proposed to reduce the PAPR value and they can be classified into two categories, the first category consists of signal distortion techniques such as clipping [30], clipping and filtering [31], [32], peak windowing [33], active constellation extension (ACE) [34], non-linear companding transforming [35]- [37], and trellis assisted constellation subset selection (TACSS) [38]. The second category includes of signal scrambling techniques such as selective mapping (SLM) [39]- [41], partial transmit sequence (PTS) [42], [43], block coding [44], interleaving technique [45], tone reservation (TR) [46], [47], and tone injection [48].…”

Section: Introductionmentioning

confidence: 99%

A Review of Partial Transmit Sequence for PAPR Reduction in the OFDM Systems

et al. 2019

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Orthogonal frequency division multiplexing (OFDM) is a superior technology for the high-speed data rate of wire-line and wireless communication systems. The OFDM has many advantages over other techniques such as its high capacity and immunity against multipath fading channels. However, one of the main drawbacks of the OFDM system is the high-peak-to-average power ratio (PAPR) that leads the system to produce in-band distortion and out-of-band radiation because of the non-linearity of the high-power amplifiers. Therefore, numerous techniques have been proposed to overcome the PAPR problem such as selective mapping, partial transmit sequence (PTS), clipping, and nonlinear companding. In this paper, the PTS technique was analytically reviewed as one of the important methods to reduce the high PAPR problem. The PAPR performance and the computational complexity level are discussed in terms of modifying the PTS technique in the frequency domain, time domain and modulation stage (inverse fast Fourier transform block). Moreover, the numerical statistic comparison of the current modified-PTS methods is introduced, and the criteria for selecting the suitable modified-PTS method in the OFDM system are also given. The simulation and the numerical calculations results show that the rows exchange-interleaving PTS scheme is the best method for reducing the PAPR value with low complexly in the frequency domain, and the cooperative PTS method is the best among the modulation stage methods, while the cyclic shift sequence PTS method achieves the superior performance in PAPR reduction and computational complexity for the time domain methods.

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Sliding the SLM-technique to Reduce the Non-Linear Distortion in OFDM Systems

Cited by 15 publications

References 36 publications

An Enhanced Partial Transmit Sequence Segmentation Schemes to Reduce the PAPR in OFDM Systems

An Enhanced Partial Transmit Sequence Segmentation Schemes to Reduce the PAPR in OFDM Systems

Post-IFFT-Modified Selected Mapping to Reduce the PAPR of an OFDM System

A Review of Partial Transmit Sequence for PAPR Reduction in the OFDM Systems

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