Partial Transmit Sequence Technique Research Articles

PAPR, Spectral Efficiency, BER and SNR Analysis of OFDM: A Novel Partial Transmit Sequence-Particle Swarm Optimization Technique

Orthogonal frequency division multiplexing (OFDM) is a widely used multicarrier modulation (MCM) technique in the field of wireless communications, specifically designed to facilitate high-speed data transmission. The use of several subcarriers inside an OFDM system for the transmission of modulated symbols results in the generation of OFDM signals with a significant peak-to-average power ratio (PAPR). In this study, we propose a novel approach for mitigating the high PAPR in wireless communication systems (WCS). Our method utilizes a partial transmit sequence (PTS) strategy, which is enhanced by using an adaptive particle swarm optimization (PSO) algorithm. In this study, we present a description of an OFDM system employing the standard PTS technique in conjunction with PSO. To mitigate computational complexity, the suggested methodology efficiently explores the optimal amalgamation of phase rotation components. Experimental findings demonstrate that the computational complexity and PAPR have been greatly minimized by the suggested method.

Investigations on Filtered OFDM with Selective Mapping Method and Partial Transmit Sequence Technique for Future Generation Mobile Communication Systems

Future generation mobile communication system requires asynchronous transmission of data, reduced out-of-band power emission, low peak-to-average power ratio, low latency, high data transmission rate, better spectrum, energy, and power efficiency, etc. Investigations on suitable waveform candidates for future-generation mobile communication have been reported in this paper. Filtered Orthogonal Frequency Division Multiplexing (F- OFDM), F- OFDM with Selective Mapping Method (SLM), and F- OFDM with Partial Transmit Sequence (PTS) technique, have been investigated. Its performances have been evaluated in terms of peak-to-average power ratio (PAPR), bit error rate (BER), and out-of-band power emissions. F–OFDM is a suitable candidate for future-generation mobile communication systems that can be used with single-rate or multirate filters. It can also be used in combination with other PAPR reduction techniques. F-OFDM with PTS technique requires a smaller number of IFFT operations than F-OFDM with SLM. The result obtained from my present investigations reveals that F-OFDM with the PTS technique has 4.3 dB less PAPR than that of OFDM at the cost of marginal increase in the BER value.

Performance Analysis of PAPR minimization in OFDM System Using Clipping, SLM and PTS Techniques

In wireless communications, Orthogonal Frequency Division Multiplexing (OFDM) is a method of modulating multicarrier signals to transmit high speed data. OFDM systems use multiple subcarriers to transmit the modulated symbols. There is a high peak to average power ratio (PAPR) in OFDM. PAPR can be reduced by using various methods. Different PAPR minimization techniques, like clipping, selective mapping (SLM) and partial transmit sequence (PTS) are presented in this project. This paper also focuses on Bit Error Rate (BER) and Signal to Noise Ratio (SNR) relative performance. A significant reduction in the PAPR and computational complexity can be seen from the results. The purpose of this study is to compare the results of an analysis recommended for PAPR reduction methods.

A LOW-COMPLEXITY PTS TECHNIQUE–BASED IMPROVED PSO ALGORITHM FOR PAPR REDUCTION IN OFDM SYSTEMS

Partial transmit sequence (PTS) is a potent and distortionless scheme frequently used to lower the high peak-to-average power ratio (PAPR) levels in orthogonal frequency division multiplexing (OFDM) signaling. Although this method effectively reduces the PAPR, its main limitation is the exponential growth in the computational expense caused by the exhaustive search for the optimal complex of rotation factors. This work proposes a suboptimal PTS scheme based on an improved particle swarm optimization (PSO) algorithm. The latter exploits heuristics to find the best-matched weighting factors complex in fewer computations. A comparison against existing techniques ascertains the superior efficiency of the proposed scheme in terms of PAPR mitigation and computational burden.

PAPR Reduction Techniques and Their BIT Error Rate Measurement at OFDM in LTE System

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)and it is indeed in use. These descriptions are simplified version of the detailed descriptions provided by 3gpp. It 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 and reduces its efficiency is the distortion of the signal caused at the High Power Amplifier (HPA) of a transmitter . Therefore, it is highly desirable to reduce the PAPR of an OFDM signal. For this, numerous techniques have been proposed to overcome the PAPR problem such as i) selective mapping(SLM) ii) partial transmit sequence (PTS), iii) clipping, iv) clipping and filtering. In this paper, the PTS technique was analytically reviewed as one of the important methods to reduce the high PAPR problem. Simulations are used to analyze the efficiency of the techniques used which signifies OFDM to be providing much better PAPR reduction and a better Bit Error Rate (BER) . From simulation results clipping method shows good PAPR reduction with significant amount of BER degradation. Clipping and filtering method shows slight increase in PAPR with small degradation in BER performance than Clipping method and both methods are computationally less complex. PTS provides good PAPR reduction with high computational complexity.

PAPR Analysis of OFDM using Partial Transmit Sequence Method

Orthogonal Frequency Division Multiplexing (OFDM) is one of the most widely used multicarrier transmission and effective technologies in today's communication networks. OFDM has many benefits and drawbacks. High Peak to Average Power Ratio (PAPR) is one of its main drawbacks. The spectral efficiency of the high-power amplifiers decreases with increasing PAPR. Therefore, maintaining a wireless system's efficiency is required to lower the PAPR. A possible method for lowering the high PAPR in OFDM systems is Partial Transmit Sequence (PTS). PTS generates a number of candidate signals, and the best signal with the lowest PAPR is chosen for transmission. The results shows that the PTS technique achieves greater PAPR minimization with less complexity. MATLAB simulation has been used to examine the OFDM system's PSD, spectral efficiency, BER performance, and PAPR analysis.

Continuous-unconstrained and global optimization for PSO-PTS based PAPR reduction of OFDM signals

Orthogonal frequency division multiplexing (OFDM) is a superior technology for the high-speed data rate of wire-line and wireless communication systems. However, one of the major drawbacks of OFDM signals is the high peak-to-average power ratio (PAPR) problem inherent in 5G waveform design. High PAPR causes OFDM signal distortion in the nonlinear region of the high power amplifier (HPA), and signal distortion leads to a decrease in bit error rate (BER). Partial transmit sequence (PTS) technique is a very attractive technique for PAPR reduction. However, to match the optimum condition on PTS for PAPR reduction, the computational unpredictability and cost of traditional PTS strategy are enormous, thus it is urgent to enhance computational efficiency to obtain the optimal PTS. In this paper, an improved scheme called Continuous-Unconstrained Particle Swarm Optimization based PTS (CUPSO-PTS) technique for optimum phase rotation factors searching is presented. A class of continuous-phase PTS schemes has been proposed to obtain the global optimal phase factor, and the theoretical boundaries can be determined in the continuous-unconstrained searching space. Conversely, when the phase factor values in continuous-unconstrained domain, the equivalent unconstrained PTS optimization can drastically accelerate convergence and reduce total calculation cost. In this paper, we compare the performance of Binary PSO based PTS (BPSO-PTS) scheme and Elitist Genetic Algorithm based PTS (EGA-PTS) scheme for 16-QAM modulation scheme. Theoretical analysis and simulations show that the proposed CUPSO-PTS scheme could provide a significant PAPR reduction in the OFDM system, which outperforms the OFDM systems with the traditional PTS scheme by 0.55 dB at CCDF of 10−3 in PAPR reduction. And 84.74% computational complexity is saved.

Filtered OFDM PAPR performance for 5G communications is improved utilizing PTS

A waveform candidate for fifth-generation (5G) communications has been recommended: the filtered orthogonal frequency division multiplexing (F-OFDM) system. Filtering-based waveform frameworks are distinguished by the suppression of out-of-band emission (OOBE) and asynchronous transmission. As a result, the new waveform candidates are still struggling with the PAPR issue. In multicarrier systems, partial transmit sequence (PTS) is an efficient way to combat the rising tendency of PAPR. The high PAPR value of an F-OFDM system is reduced using the PTS technique in this study. The OFDM system is then put up against this one. Other relevant metrics, such as frequency localization, bit error rate (BER), and computational complexity, are evaluated and analysed in both systems with and without PTS. According to simulation studies, F-OFDM based on PTS provides better PAPR, BER, and OOBE than OFDM. F-BER OFDM's is unaffected by the PTS technique's implementation.

Precoded SLM and PTS Scheme for Reduced PAPR in OFDM for Wireless Communications

Orthogonal Frequency Division Multiplexing (OFDM) contribute high data rates in current as well as future wireless communication systems but it aches from high Peak to Average Power Ratio (PAPR). But this high PAPR makes the High-Power Amplifier (HPA) complex which increases the cost of it and leads to the drawbacks like Inter Carrier Interference (ICI) and rise in out of band radiation. Even though many techniques are there to decrease the complexity of HPA by reducing the PAPR, Selected Mapping (SLM) and the Partial Transmit Sequence (PTS) provides less PAPR with low complexity. In this paper, both PTS and SLM are combined with Discrete Sine Transform (DST) and their PAPR and efficiencies are also compared with OFDM signal. The proposed hybrid DST-PTS and DST-SLM provides less PAPR compared to OFDM, SLM and PTS techniques with low complexity. Also, the bit error rate for DST-SLM and DST-PTS techniques are compared for different values of SNR. In future wireless communication systems, these proposed techniques can be used as they provide less bit error rate and less PAPR with low complexity

PAPR Reduction in OFDM Systems Using Hybrid Zadoff-Chu Transform Precoding and Partial Transmit Sequence

Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier modulation (MCM) scheme that plays a significant role in digital wireless communication. As a result of its high data rate capability and immunity to multipath fading effect, among others, OFDM remains an ideal technology for 5G communication systems and beyond. Unfortunately, a major drawback of this technology is the high peak-to-average power ratio (PAPR). Nevertheless, many techniques for reducing PAPR have been proposed in the past to address this problem. However, all the techniques previously used have limitations such as high computational complexity, data rate loss, high signal distortion, increase in bandwidth, increase in transmit power, and memory requirements. In this paper, a hybrid technique that combines Zadoff-Chu Transform (ZCT) precoding and Partial Transmit Sequence (PTS) for reducing high PAPR in OFDM signals is presented. To reduce the data rate loss and computational complexity in PTS when a large subblock is used, a Zadoff-Chu precoding is applied to OFDM symbols to precode the symbol before applying PTS with a fewer number of subblocks. An OFDM model was developed where ZCT and PTS techniques were implemented. The performance of the hybrid model was analyzed using Power Spectral Density (PSD), Complementary Cumulative Distribution Function (CCDF), and Bit Error Rate (BER). The simulation result indicates that the hybrid ZCT-PTS provides a better result than using either Zadoff-Chu precoding technique or Partial Transmit Sequence technique separately. A PAPR of 4.2 dB and BER of 3dB is achieved for hybrid ZCT-PTS. The hybrid technique provides a better system performance when compared with Conventional OFDM systems.

Randomization Approaches for Reducing PAPR with Partial Transmit Sequence and Semidefinite Relaxation

To reduce peak-to-average power ratio, we propose a method to choose a suitable vector for a partial transmit sequence technique. With a conventional method for this technique, we have to choose a suitable vector from a large amount of candidates. By contrast, our method does not include such a selecting procedure, and consists of generating random vectors from the Gaussian distribution whose covariance matrix is a solution of a relaxed problem. The suitable vector is chosen from the random vectors. This yields lower peak-to-average power ratio, compared to a conventional method for the fixed number of random vectors.

A Low Computational Complexity Algorithm of PTS Technique for PAPR Reduction in the 4G and 5G Systems

The (OFDM) defined as orthogonal multiplex frequency distribution system is very popular of the design of waveforms for high speed data communication in 4G wireless technology. In addition, a filter-based waveform design, such as filtered OFDM (F-OFDM), has been proposed as a candidate for the 5G technology waveform in order to overcome the current weaknesses of OFDM. And 5G requirements. The high average peak ratio (PAPR) is taken as the main obstacle to OFDM and remains an inherent problem with F-OFDM since both systems support orthogonal transmission. In this study, a new efficient algorithm called groupings of complex variants of PTS (G-C-PTS) was proposed to reduce the level of high complexity in PTS. G-C-PTS can significantly reduce complexity with a slight decrease in PAPR performance compared to traditional PTS. In addition, comparisons were made between (OFDM) and (F-OFDM) systems based on the GC-PTS algorithm for PAPR, bit error rate (BER) and spectral power density (PSD) to validate the proposed algorithm. Partial transmit sequence (PTS) procedure is considered one of the production strategies to decrease the high peak-to-average power ratio (PAPR) in the 4G waveform plane, for example multiplex frames for symmetric repetition division (OFDM).

TanhR nonlinear companding scheme for UWA systems

ABSTRACT The basic idea of this letter is concerned with the large Peak-to-Average Power Ratio (PAPR) problem in multi-carrier Under-Water Acoustic (UWA) communication systems that implement Orthogonal Frequency Division Multiplexing (OFDM). A Tangent Rooting (TanhR) companding technique is presented in this paper to reduce the PAPR in UWA communication systems. This technique achieves a noticeable reduction of the PAPR in UWA systems, while maintaining a good Bit Error Rate (BER) performance . Channel equalisation with Linear Minimum Mean Square Error (LMMSE) and Zero-Forcing (ZF) equalisers is considered in this paper. Simulation results ensure superiority of the proposed technique compared to the Selected Mapping (SLM) and the Partial Transmit Sequence (PTS) techniques from both the PAPR and BER perspectives.

Demonstrating the Effect of Using Goppa Coding with Hybrid Selective Mapping and Partial Transmit Sequence Technique for PAPR Reduction in OFDM Systems

Orthogonal Frequency Division Multiplexing is a multi-carrier modulation technique which provides numerous advantages like high spectral efficiency, minimal interference, low multipath fading, etc. But Peak-to-average Power Ratio is a severe challenge in using such multiplexing technique as it introduces distortions in nonlinear devices. Various Peak-to-average Power Ratio reduction techniques have been investigated in the literature to improve the performance of Orthogonal Frequency Division Multiplexing systems. But, each of them suffers either from high complexity or degraded bit error rate or less spectral efficiency. For reducing Peak-to-average Power Ratio more effectively, a hybrid combination of Partial Transmit Sequence with Selective Mapping is detected to show better performance. In this paper, we have combined Goppa coding technique with this hybrid Selective Mapping and Partial Transmit Sequence for further improving the performance. Along with Peak-to-average Power Ratio reduction capability, the proposed technique also has inherent error control mechanism due to the use of coding. Based on the simulation results, we have concluded that the proposed technique provides good amount of Peak-to-average Power Ratio reduction than conventional techniques. The proposed technique is analyzed for different number of Orthogonal Frequency Division Multiplexing symbol candidates for Selective Mapping and different number of block divisions for Partial Transmit Sequence. Further, this technique is simulated for different number of subcarriers and modulation order and the simulation results are compared with each other. The proposed technique also shows better Bit error rate values for high Signal-to-Noise ratio.

PAPR reduction of asymmetrically clipped optical OFDM signals: Optimizing PTS technique using improved flower pollination algorithm

Orthogonal frequency division multiplexing (OFDM) is a practical approach for indoor optical communications because of its high rate data transmission and high power efficiency. The high peak-to-average power ratio (PAPR) is the main problem of optical OFDM signals which, degrades the system performance due to the LED nonlinearity. Partial transmit sequence (PTS) is the most popular PAPR reduction technique because of its distortionless characteristics and high performance. But, PTS has a high computational complexity, because it requires an exhaustive search to obtain the optimal phase factors. To reduce the search complexity of the PTS, we introduce a new swarm intelligence algorithm, called improved flower pollination (IFP) algorithm. The IFP algorithm is a novel optimization technique derived from the pollination behavior of flowers. The proposed IFP–PTS approach is applied in the asymmetrically clipped optical OFDM (ACO-OFDM) system and evaluated using several PAPR reduction benchmarks and compared with different state-of-the-art approaches in terms of PAPR reduction performance and computational complexity. The results justify the advantages of the IFP–PTS method compared with its counterparts.

Reduction of Peak Average Power Ratio for FBMC Waveform with P-PTS Technique

Background: In this work, Peak Average Power Ratio (PAPR) reduction is achieved in Filter Bank Multi-Carrier (FBMC) by using a Pretreated Partial Transmit Sequence (P-PTS) technique. High PAPR is seen as unitary of the major problems in FBMC. Aim: The proposed work present a double stage optimization technique termed P-PTS. Methods: In the first step, several overlying signals cooperative optimization method that the phase angle sequences of current signal is intended and improved according to preceding overlapped signals. An efficient PTS scheme for PAPR reduction is put through in the second form. Results: The suggested technique is carried out by changing the value of U and V to analyze the BER and PAPR performance of the system. It is likewise noted that increasing the value of V can significantly lessen the peak power. Conclusion: Simulation results reveal that the performance of the proposed P-PTS technique is better than conventional PAPR reduction techniques with simple computations and the design complication can be traded off further compliantly with PAPR diminution.

PTS scheme based on MCAKM for peak‐to‐average power ratio reduction in OFDM systems

This study considers the application of the partial transmit sequence (PTS) technique to reduce the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. The conventional PTS approach has proved its high effectiveness in PAPR reduction for OFDM signals where the reduction performance of PAPR depends mainly on phase rotation factors. Finding the optimal phase rotation factors requires an exhaustive computationally task, which is a serious implementation problem in practical systems. To fix this issue of computational complexity and reduce the PAPR at the same time, in the present work, a novel PTS approach based on multi-population cultural algorithm adopting knowledge migration (MCAKM) has been proposed for optimal phase rotation factors search. Computer simulation results show that the proposed MCAKM–PTS technique leads to a better PAPR reduction and bit error rate performance with a significant reduction in computational complexity compared to the conventional PTS and the previously optimisation algorithms applied to PTS such as particle swarm optimisation, artificial bee colony, and electromagnetism-like algorithm.

Cumulative symbol optimization–based partial transmit sequence technique for PAPR reduction in low complexity GFDM system

AbstractThe new waveform called generalized frequency division multiplexing (GFDM), which has been increasing its popularity among the fifth generation (5G) waveform candidates day by day, is suggested very recently to meet the requirements of the next‐generation cellular systems. On the other hand, it is possible to generate and demodulate the GFDM signal with a less processing load by using low‐complexity GFDM (LC‐GFDM) system proposed shortly after the GFDM scheme. However, similar to the GFDM and the other multicarrier systems, high peak‐to‐average power ratio (PAPR) problem stands as one of the biggest obstacles, making difficulties for smooth communication in the LC‐GFDM system. In this system, the GFDM symbols obtained by the multiplication of time domain GFDM data sequences with circularly shifted prototype filter impulse responses are added together to achieve the transmission signal. Due to the related symbol addition process, direct application of the conventional partial transmit sequence (C‐PTS) technique, which was actually first developed for orthogonal frequency division multiplexing (OFDM), to the LC‐GFDM system without any modification will be useless. For this reason, we developed a new technique called cumulative symbol optimization–based partial transmit sequence (CSO‐PTS) for PAPR reduction in the LC‐GFDM system. In the simulations, the CSO‐PTS technique is compared to two different PAPR reduction methods called selective mapping and GreenOFDM. Simulation results evidently demonstrates that our novel proposal outperforms the other considered methods by ensuring quite efficient PAPR reduction, side lobe suppression, and bit error rate improvement in the LC‐GFDM system.

A novel hybrid genetic algorithm to reduce the peak-to-average power ratio of OFDM signals

Orthogonal frequency division multiplexing (OFDM) is an effective approach for high rate data transmission in telecommunication systems. The high peak-to-average power ratio (PAPR) is one of the main drawbacks of the OFDM systems. Partial transmit sequence (PTS) is an efficient method to decrease the PAPR of OFDM signals. But, the PTS technique needs an exhaustive search over all combinations of phase rotation factors and the computational complexity grows exponentially with the number of sub-blocks. To reduce the search complexity, we introduce a novel hybrid genetic algorithm (HGA) in the PTS technique. The important aspect of the proposed method is the choice of salient phase factors to reduce the high PAPR. The proposed HGA-PTS approach incorporates novel local search operations that are designed and embedded in the genetic algorithm to explore the optimum phase factors. Numerical simulations are performed for 16-QAM modulated symbols and the obtained results show that the HGA-PTS significantly reduces both the PAPR and search complexity.

Dual symbol optimization‐based partial transmit sequence technique for PAPR reduction in WOLA‐OFDM waveform

SummaryWeighted overlap and add‐orthogonal frequency division multiplexing (WOLA‐OFDM) is a new waveform proposed recently for meeting the requirements of fifth generation (5G) telecommunication standards. In spite of being a serious 5G waveform candidate, WOLA‐OFDM is exposed to the problem of high peak to average power ratio (PAPR) similar to the other waveforms in which multicarrier transmission strategy is employed. Due to the overlapping nature of WOLA‐OFDM waveform, where the extension of the current symbol is overlapped with the extension of the previous symbol, it will not be efficient to apply conventional PTS (C‐PTS) directly to the WOLA‐OFDM waveform. Therefore, in this paper, we propose dual symbol optimization‐based partial transmit sequence (DSO‐PTS) technique for PAPR reduction in WOLA‐OFDM waveform. In our proposed technique, two adjacent symbols are jointly considered when searching for the optimal data block with minimum PAPR unlike the C‐PTS where the adjacent symbols are optimized individually. In the simulations, our proposed DSO‐PTS technique, C‐PTS, and GreenOFDM that is developed recently by modifying the conventional selective mapping (SLM) method are compared with each other with regard to PAPR reduction performance for different search numbers (SNs). In addition, the effects of DSO‐PTS, C‐PTS, and GreenOFDM on the amount of out of band (OOB) radiation in the power spectral density (PSD) graph of WOLA‐OFDM employing solid state power amplifier (SSPA) is measured for different SNs and input back off (IBO) values. According to the simulation results, our proposed DSO‐PTS technique clearly demonstrates a superior PAPR reduction and PSD performance.