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.

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 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 Design of an Adaptive Predistorter for Solid State Power Amplifier in Wireless OFDM Systems

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Rui J. P. de Figueiredo ◽  
Lin Fang ◽  
Byung Moo Lee
Keyword(s):  
Performance Improvement ◽  
Power Amplifier ◽  
Communication Systems ◽  
Power Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Wireless Communication Systems ◽  
Ofdm Systems ◽  
High Power Amplifier ◽  
Ofdm Signals

Orthogonal frequency division multiplexing (OFDM) is a powerful modulation choice for wideband wireless communication systems. However, its high peak-to-average power ratio greatly limits the high power amplifier (HPA) power efficiency. Here, we present the design of an adaptive predistorter to compensate the distortion caused by the HPA. Specifically, we deal with the implementation issue of the proposed predistorter in Lee and de Figueiredo's work (2006). The performance improvement by predistorter is verified by both floating-point simulation and fixed-point simulation, where the latter includes the distortion effects from the hardware. The bit widths for OFDM signals, ADC, and DAC are evaluated, and the bit width of 10 is shown to be sufficient for the hardware design.

scholarly journals Polygon Number Algorithm for Peak-to-Average Ratio Reduction of Massive 5G Systems Using Modified Partial Transmit Sequence Scheme

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hayder Alkatrani ◽  
Muhammad Ilyas ◽  
Salam Alyassri ◽  
Ali Nahar ◽  
Fadi Al-Turjman ◽  
...  
Keyword(s):  
Side Information ◽  
Average Power ◽  
Transmission Efficiency ◽  
Similar Data ◽  
Ofdm Systems ◽  
Partial Transmit Sequence ◽  
High Power Amplifier ◽  
Major Shortcoming ◽  
Selective Mapping ◽  
Ratio Reduction

The high peak-to-average power ratio (PAPR) of the transmit signal is a major shortcoming of OFDM systems, which results in band radiation and distortion due to the nonlinearity of the high-power amplifier (H.P). To resolve the traditional OFDM high-PAPR issue, where the transmit sequence is designed to avoid similar data from being sent in the same order to reduce PAPR, there are numerous conventional ways for lowering the PAPR for OFDM system, such as selective mapping, tone reservation, block coding, filtering, clipping, and partial transmit sequence (PTS). This study proposes a new method called polygon number algorithm (PN) with conventional partial transmit sequence (C-PTS). This method (PN-PTS) processes the entered data before sending it, taking advantage of the number nonsimilarity according to the geometry of the number to prevent direct sending of similar data via PTS, and thus, this improved the level of PAPR rise in the proposed system. The amount of reduction that can be achieved in PAPR is up to 8 dB by different techniques. The best result obtained was the amount of reduction between the conventional method and the proposed method is 4.5683 where N = 64 . Besides this, there is no transmission of side information (SI), which improves transmission efficiency. Finally, this method is easy in the calculation process and the ciphering and deciphering of data, which adds a few calculations.

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.

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.

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