scholarly journals AN EFFICIENT METHOD FOR PAPR REDUCTION IN OFDM SYSTEMS WITH REDUCED COMPLEXITY

2013 ◽  
pp. 96-100
Author(s):  
PRITANJALI KUMARI ◽  
US TRIAR
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
High Peak ◽  
Papr Reduction ◽  
Power Calculation ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Reduced Complexity

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.

scholarly journals Peak-to-Average Power Ratio Reduction Based on Cross- Correlation in Orthogonal Frequency Division Multiplexing Systems

2018 ◽  
Vol 1 (1) ◽  
pp. 87
Author(s):  
Mohsen Kazemian
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Cross Correlation ◽  
Average Power ◽  
Complete Analysis ◽  
Papr Reduction ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Power Ratio Reduction

<p>Three of the most important techniques of Peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems are Partial Transmit Sequence PAPR (PTS-PAPR), Selected Mapping PAPR (SLM-PAPR) and Cross-Correlation-PTS. This paper performs a complete analysis on these three techniques providing simulation and discussion of their performance on PAPR reduction and bit error rate (BER). Moreover, the comparison of these methods by using Saleh model amplifier in an OFDM system is provided. The results show that PTS-PAPR outperforms the Cross-Correlation-PTS in terms of PAPR performance while Cross-Correlation-PTS method is more efficient in BER reduction compared to PTS-PAPR and SLM-PAPR.</p>

scholarly journals A CCM-Based OFDM System with Low PAPR for Sparse Source

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Qinbiao Yang ◽  
Zulin Wang ◽  
Qin Huang
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Coded Modulation ◽  
High Peak ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm System ◽  
Simulation Results ◽  
Clipping And Filtering

Orthogonal frequency division multiplexing (OFDM) usually suffers high peak-to-average power ratio (PAPR). As shown in this paper, PAPR becomes even severe for sparse source due to many identical nonzero frequency OFDM symbols. Thus, this paper introduces compressive coded modulation (CCM) in order to restrain PAPR by reducing identical nonzero frequency symbols for sparse source. As a result, the proposed CCM-based OFDM system, together with iterative clipping and filtering, can efficiently restrain the high PAPR for sparse source. Simulation results show that it outperforms about 4 dB over the traditional OFDM system when source sparsity is 0.1.

scholarly journals Analytical Investigation on Papr Reduction in OFDM Systems Using Golay Codes

2014 ◽  
Vol 65 (5) ◽  
pp. 289-293 ◽  
Author(s):  
Sabhyata Uppal ◽  
Sanjay Sharma ◽  
Hardeep Singh
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Analytical Investigation ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Common Technique ◽  
Golay Codes ◽  
Modulation Code

Abstract Orthogonal frequency division multiplexing (OFDM) is a common technique in multi carrier communications. One of the major issues in developing OFDM is the high peak to average power ratio (PAPR). Golay sequences have been introduced to construct 16-QAM and 256-QAM (quadrature amplitude modulation) code for the orthogonal frequency division multiplexing (OFDM), reducing the peak-to-average power ratio. In this paper we have considered the use of coding to reduce the peakto- average power ratio (PAPR) for orthogonal frequency division multiplexing (OFDM) systems. By using QPSK Golay sequences, 16 and 256 QAM sequences with low PAPR are generated

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.

scholarly journals Performance Investigation of Peak Shrinking and Interpolating the PAPR Reduction Technique for LTE-Advance and 5G Signals

Information ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 20 ◽  
Author(s):  
Somayeh Mohammady ◽  
Ronan Farrell ◽  
David Malone ◽  
John Dooley
Keyword(s):  
Fourier Transform ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Papr Reduction ◽  
Rf Power Amplifiers ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Waveform Generation ◽  
5G Systems

Orthogonal frequency division multiplexing (OFDM) has become an indispensable part of waveform generation in wideband digital communication since its first appearance in digital audio broadcasting (DAB) in Europe in 1980s, and it is indeed in use. As has been seen, the OFDM based waveforms work well with time division duplex operation in new radio (NR) systems in 5G systems, supporting delay-sensitive applications, high spectral efficiency, massive multiple input multiple output (MIMO) compatibility, and ever-larger bandwidth signals, which has demonstrated successful commercial implementation for 5G downlinks and uplinks up to 256-QAM modulation schemes. However, the OFDM waveforms suffer from high peak to average power ratio (PAPR), which is not desired by system designers as they want RF power amplifiers (PAs) to operate with high efficiency. Although NR offers some options for maintaining the efficiency and spectral demand, such as cyclic prefix based (CP-OFDM), and discrete Fourier transform spread based (DFT-S-OFDM) schemes, which have limiting effects on PAPR, the PAPR is still as high as 13 dB. This value increases when the bandwidth is increased. Moreover, in LTE-Advance and 5G systems, in order to increase the bandwidth, and data-rate, carrier aggregation technology is used which increases the PAPR the same way that bandwidth increment does; therefore, it is essential to employ PAPR reduction in signal processing stage before passing the signal to PA. In this paper, we investigate the performance of an innovative peak shrinking and interpolation (PSI) technique for reducing peak to average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) based signals at waveform generation stage. The main idea behind the PSI technique is to extract high peaks, scale them down, and interpolate them back into the signal. It is shown that PSI technique is a possible candidate for reducing PAPR without compromising on computational complexity, compatible for existing and future telecommunication systems such as 4G, 5G, and beyond. In this paper, the PSI technique is tested with variety of signals in terms of inverse fast Fourier transform (IFFT) length, type of the signal modulation, and applications. Additional work has been carried out to compare the proposed technique with other promising PAPR reduction techniques. This paper further validates the PSI technique through experimental measurement with a power amplifier (PA) test bench and achieves an adjacent channel power ratio (ACPR) of less than –55 dBc. Results showed improvement in output power of PA versus given input power, and furthermore, the error vector magnitude (EVM) of less than 1 % was achieved when comparing of the signal after and before modification by the PSI technique.

scholarly journals Cos and Sine (CAS) Pre-coding for PAPR drop in OFDM systems

2019 ◽  
Vol 8 (2S11) ◽  
pp. 3147-3150
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Sine Transform ◽  
Canonic Signed Digit ◽  
The Common ◽  
Papr Performance

Extreme Peak to Average Power Ratio (PAPR) is as yet the common significant test in Orthogonal Frequency Division Multiplexing (OFDM) framework. A consolidated strategy of Discrete Cosine Transform (DCT) and Discrete Sine Transform (DST) precoding based CSD procedure for PAPR decrease in OFDM frameworks are represented in this article. Here, the constants are spoken to utilizing a canonic signed digit (CSD) depiction. For bit-positions relating to a positive digit in the CSD portrayal, the bit-item is included that segment. For negative digits in the CSD portrayal, a one-piece two's supplement portrayal is utilized. To evade sign-expansion a remuneration vector is utilized. Analyzed results demonstrate that our proposed procedure can diminish the PAPR performance very effectively than following the conventional PAPR lessening methods.

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