A Pilot Design Method Based on Cyclic Shift PTS

2014 ◽  
Vol 519-520 ◽  
pp. 939-944 ◽  
Author(s):  
Qi Song Yang ◽  
Ken Long
Keyword(s):  
Time Domain ◽  
Orthogonal Frequency Division Multiplexing ◽  
Design Method ◽  
Side Information ◽  
Average Power ◽  
Cyclic Shift ◽  
Ofdm Systems ◽  
Channel Response ◽  
Phase Rotation ◽  
Pilot Design

Partial transmit sequence (PTS) scheme is one of the most effective way to reduce peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. The cyclic shift on time-domain PTS has better performance in PAPR reduction than that of the conventional PTS (C-PTS), and the receiver can recover phase rotations without using side information (SI). However, the receiver must know channel response before detecting and perform complex operations in order to detect the phase rotation factors. In this letter we proposed a pilot design method based on cyclic shift on time-domain PTS, which can estimate phase rotation factors and channel response more easily. Simulation results show that the PAPR performance of the proposed method is approximately same as the cyclic shift PTS scheme and the BER performance is also as well as C-PTS with perfect SI in multipath channel scene.

scholarly journals Estimation of Cyclic Shift with Delayed Correlation and Matched Filtering in Time Domain Cyclic-SLM for PAPR Reduction

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Panca Dewi Pamungkasari ◽  
Yukitoshi Sanada
Keyword(s):  
Time Domain ◽  
Side Information ◽  
Average Power ◽  
Matched Filtering ◽  
Cyclic Shift ◽  
Ofdm Systems ◽  
High Power Amplifier ◽  
Critical Issues ◽  
Cyclic Shifts ◽  
Selective Mapping

Time domain cyclic-selective mapping (TDC-SLM) reduces the peak-to-average power ratio (PAPR) in OFDM systems while the amounts of cyclic shifts are required to recover the transmitted signal in a receiver. One of the critical issues of the SLM scheme is sending the side information (SI) which reduces the throughputs in wireless OFDM systems. The proposed scheme implements delayed correlation and matched filtering (DC-MF) to estimate the amounts of the cyclic shifts in the receiver. In the proposed scheme, the DC-MF is placed after the frequency domain equalization (FDE) to improve the accuracy of cyclic shift estimation. The accuracy rate of the propose scheme reaches 100% at Eb/N0 = 5 dB and the bit error rate (BER) improves by 0.2 dB as compared with the conventional TDC-SLM. The BER performance of the proposed scheme is also better than that of the conventional TDC-SLM even though a nonlinear high power amplifier is assumed.

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.

SELECTIVECODEWORD SHIFT (SCS) TECHNIQUE FOR PAPR REDUCTION OF OFDM SYSTEMS

2016 ◽  
Vol 78 (5-9) ◽  
Author(s):  
Ezmin Abdullah ◽  
Azlina Idris
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Side Information ◽  
Average Power ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Data Sequence ◽  
Wireless Applications ◽  
Selective Mapping ◽  
Ofdm Signals ◽  
Peak Value

Peak to Average Power Ratio (PAPR) has been known to be a common problem in Orthogonal Frequency Division Multiplexing (OFDM). The peak value of power signals has contributed to other problems, thus the implementation of OFDM system in many wireless applications has been growing slowly. There are many techniques being discussed to reduce the PAPR in OFDM systems where one of them is reduction through scrambling. In this paper, a technique that is based on scrambling method in order to reduce high PAPR in OFDM system is introduced. This proposed technique is called the Selective Codeword Shift (SCS). The key idea of SCS is to produce a scramble data sequence where the candidate with minimum PAPR will then be selected for transmission. This has shown an improvement in reducing PAPR as compared to original OFDM signals and the conventional Selective Mapping (SLM) technique with 29.5% improvement. This technique also has the advantage of lower computational complexity as compared to conventional SLM where no multiplication of the phase factor involved in the process and no explicit side information was needed to retrieve the transmitted data at the receiver.

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 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.

scholarly journals PAPR Reduction Approach Based on Channel Estimation Pilots for Next Generations Broadcasting Systems

2011 ◽  
Vol 2011 ◽  
pp. 1-17 ◽  
Author(s):  
Anh-Tai Ho ◽  
Jean-François Helard ◽  
Youssef Nasser ◽  
Yves Louet
Keyword(s):  
Channel Estimation ◽  
Spectral Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Side Information ◽  
Estimation Error ◽  
Average Power ◽  
Gradient Algorithm ◽  
Papr Reduction ◽  
Blind Detection ◽  
Ofdm Systems

A novel peak-to-average power ratio (PAPR) reduction technique for orthogonal frequency division multiplexing (OFDM) systems is addressed. Instead of using dedicated pilots for PAPR reduction as with tone reservation (TR) method selected by the DVB-T2 standard, we propose to use existing pilots used for channel estimation. In this way, we avoid the use of reserved tone pilots and then improve the spectral efficiency of the system. In order to allow their recovery at the receiver, these pilots have to follow particular laws which permit their blind detection and avoid sending side information. In this work, we propose and investigate a multiplicative law operating in discrete frequency domain. The operation in discrete domain aims at reducing degradation due to detection and estimation error in continuous domain. Simulation results are performed using the new DVB-T2 standard parameters. Its performance is compared to the DVB-T2 PAPR gradient algorithm and to the second-order cone programming (SOCP) competitive technique proposed in the literature. We show that the proposed technique is efficient in terms of PAPR reduction value and of spectral efficiency while the channel estimation performance is maintained.

PAPR Reduction in OFDM System Using Hybrid OICF and Phase Rotation Scheme

2019 ◽  
Vol 40 (2) ◽  
pp. 109-112 ◽  
Author(s):  
Richa Bhatia ◽  
Vivek Upadhyay
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Papr Reduction ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Linear Region ◽  
High Power Amplifier ◽  
Phase Rotation ◽  
Rotation Scheme

Abstract Peak to average power ratio (PAPR) is one of the major limitations of orthogonal frequency division multiplexing (OFDM) systems because the higher PAPR induces the signal to get out of linear region of high power amplifier (HPA). In this article, a hybrid PAPR reduction scheme based on the combination of optimized iterative clipping and filtering (OICF) method and phase rotation is proposed. Using phase rotation, signal’s initial PAPR has been reduced by 14.23 dB and then OICF further reduces the final PAPR by 1.37 dB. Decreased PAPR will play an important role in reducing systems power consumption.

Experimental Demonstration for PAPR Reduction in OFDM System Using Partial-OSLM Technique

2018 ◽  
Vol 27 (07) ◽  
pp. 1850106 ◽  
Author(s):  
M. I. Al-Rayif ◽  
H. Seleem ◽  
A. Ragheb ◽  
S. Alshebeili
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Side Information ◽  
Average Power ◽  
Papr Reduction ◽  
Ofdm Systems ◽  
Power Spectral ◽  
Comparable Performance ◽  
4G Wireless ◽  
Selective Mapping

Orthogonal frequency division multiplexing (OFDM) modulation is proposed in 4G wireless communication systems, and is under consideration for the next generation 5G systems. This is due to the higher spectral efficiency (SE) and the better immunity to channel distortions. One of the shortcomings in OFDM is its high peak-to-average power ratio (PAPR). Several schemes have been proposed to reduce the PAPR in OFDM systems. This includes clipping, coding, and pre/post-distortion schemes with or without side information. In this paper, we experimentally demonstrate one of the most promising method, to mitigate the effect of PAPR, entitled the partial orthogonal selective mapping (POSLM). The experimental results show a comparable performance with respect to the simulation results in terms of PAPR reduction, power spectral density (PSD), and bit error rate (BER) metrics.

scholarly journals Preamble design for estimation and compensation of channel distortion parameters in OFDM systems

2014 ◽  
Vol 3 ◽  
Author(s):  
Emmanuel Manasseh ◽  
Shuichi Ohno ◽  
Toru Yamamoto
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Carrier Frequency Offset ◽  
Mean Squared Error ◽  
Average Power ◽  
Ofdm Systems ◽  
Channel Estimate ◽  
Phase Rotation ◽  
Channel Distortion ◽  
Distortion Parameters ◽  
Frequency Selective Channels

In this paper, preamble design for estimation and compensation of channel distortion parameters (or channel impairments) in orthogonal frequency-division multiplexing (OFDM) transmission over peak-limited channels is studied. Specifically, the designed preamble considers the estimation of frequency selective channels, carrier frequency offset (CFO), in-phase/quadrature-phase (I/Q) imbalance together with the minimization of peak-to-average power ratio (PAPR) of the transmitted signals. In the proposed design, we employ adaptive Markov chain Monte Carlo (AMCMC) techniques to select preamble sequence that minimizes the channel estimate mean-squared error while suppressing the effect of the I/Q mismatch. AMCMC algorithm is also deployed to select phase information to the designed preamble in order to minimize the PAPR of the oversampled preamble signals in time domain. To estimate CFO, maximum likelihood-based scheme that utilizes two successive OFDM preambles is employed, and the CFO is estimated by considering phase rotation between two consecutive received OFDM preambles. Numerical simulations are provided to verify the efficacy of the proposed design.

scholarly journals Hybrid Model for PAPR Minimization in OFDM System

2021 ◽  
pp. 16-30
Keyword(s):  
Computational Complexity ◽  
Orthogonal Frequency Division Multiplexing ◽  
New Technologies ◽  
Hybrid Methods ◽  
Side Information ◽  
Hybrid Approach ◽  
Average Power ◽  
Ofdm Systems ◽  
Hybrid Approaches ◽  
Availability Constraints

The technology has been growing rapidly in the form of portable wireless devices that can perform multiple functions to cope with the state-of-the-art technology and synchronization. A total device capacity must be increased to accommodate new wireless applications. This can be achieved by leveraging new technologies, with higher data rates. Spectrum pooling has gained immense popularity, with increased demand for frequency range and bandwidth availability constraints. Statistics suggest that much of the spectrum licensed is not used all the time. Because of the transmitter's nonlinearity nature, the large (peak to average power ratio (PAPR)) phenomenon is a drawback in orthogonal frequency division multiplexing (OFDM). Several hybrid approaches have recently been implemented to minimize PAPR's high value, at the expense of increasing the level of computational complexity in the system. In this paper, a new hybrid approach has been introduced in parallel to combine the selective mapping approach (SLM) with the partial transmit sequence (PTS) approach to improve the efficiency of PAPR reduction with lower numerical method complexity. The findings reveal that the OFDM systems with the proposed hybrid approach have better efficiency in terms of PAPR elimination, side-information, and computational complexity compared to current hybrid methods. Also, a hybrid approach proposed output could be maintained without degradation. Index Terms: OFDM, PTS, PAPR, SLM

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