Partial transmitting sequence method based on trellis factor search

To obtain good trade-offs between complexity and performance onpeak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM)using partial transmitting sequence (PTS) schemes, a trellis structure based PTS factor searchmethod is proposed. The trellis search is with a variant constraint length L_C, 1 ≤ L_C ≤ V-1,where V is the number of PTS subblocks. The method is to decide a PTS factor by searching all thepossible paths obtained by varying L_C consecutive factors. The trellis search can be viewed as ageneral PTS factor search model. If L_C = V-1, it is a full search, and if L_C = 1, it is aniterative search. Using different constraint lengths, trellis factor search PTS exhibits differentPAPR reduction performances. A larger L_C results in a better performance and L_C = V-1 results inthe optimum. However, a larger L_C requires more computation. This helps to choose a good trade-offbetween complexity and performance.

Phase Factor Sequences Algorithm in Partial Transmit Sequence

Partial transmit sequence (PTS) is a promising technique for peak-to-average power ratio (PAPR) re-duction in orthogonal frequency division multiplexing (OFDM). While in optimal PTS, an exhaustive search for all combinations of phase factor sequences is required, this results in huge computation. In this paper, by introducing the orthogonal design, a phase factor sequences algorithm is proposed. The algorithm uses orthogonal table to gen-erate phase factor sequences, and the regular PAPR computation result is then followed by the parameter estima-tion. The simulation result shows that the proposed algorithm reduces the computation notably and obtains a good PAPR performance approaching the optimal PTS.

Low-complexity PTS scheme based on phase factor sequences optimization

In this paper, a new partial transmit sequence（PTS）scheme with low computational complexity is proposed for the problems of high computational complexity in the conventional PTS method. By analyzing the relationship of candidate sequences in the PTS method under the interleaved partition method, it has been discovered that some candidate sequences generated by phase factor sequences have the same peak average power ratio（PAPR）. Hence, phase factor sequences can be optimized to reduce their searching times. Then, the computational process of generating candidate sequences can be simplified by improving the utilization of data and minimizing the calculations of complex multiplication. The performance analysis shows that, compared with the conventional PTS scheme, the proposed approach significantly decreases the computational complexity and has no loss of PAPR performance.

PSO-DBNet for Peak-to-Average Power Ratio Reduction Using Deep Belief Network

Data transmission through a wireless network has faced various signal problems in the past decades.The orthogonal frequency division multiplexing(OFDM)technique is widely accepted in multiple data transfer patterns at various frequency bands.A recent wireless communication network uses OFDM in longterm evolution(LTE)and 5G,among others.The main problem faced by 5G wireless OFDM is distortion of transmission signals in the network.This transmission loss is called peak-to-average power ratio(PAPR).This wireless signal distortion can be reduced using various techniques.This study uses machine learning-based algorithm to solve the problem of PAPR in 5G wireless communication.Partial transmit sequence(PTS)helps in the fast transfer of data in wireless LTE.PTS is merged with deep belief neural network(DBNet)for the efficient processing of signals in wireless 5G networks.Result indicates that the proposed system outperforms other existing techniques.Therefore,PAPR reduction in OFDM by DBNet is optimized with the help of an evolutionary algorithm called particle swarm optimization.Hence,the specified design supports in improving the proposed PAPR reduction architecture.

Correlation-based subblock partition design for PTS approach

In order to exploit the capability of the peak-to-average power ratio（PAPR）reduction afforded by the partial transmit sequences （PTS）approach in orthogonal frequency division multiplexing（OFDM）systems, subblock partition schemes for the PTS approach are studied. The motivation is to establish the relationship between the subblock partition and the capability of PAPR reduction through the periodic autocorrelation functions （ACFs）of partial transmit sequences and the periodic cross-correlation functions（CCFs）of signal candidates.Let Q represent the variation of the square magnitudes of ACFs.It is found that the lower the Q-value is, the better PAPR performance can be achieved, which is introduced as a design criterion for subblock partition.Based on this criterion, four common partition methods are compared and an efficient partition strategy is proposed. It is shown that structured partition schemes with low computational complexity have a large Q-value, leading to a poor PAPR performance.The new strategy can be regarded as a trade-off between PAPR performance and computational complexity.The simulation results show that the strategy can achieve an optimal performance with a relatively low complexity and, moreover,does not increase the amount of side information.

An Efcient Genetic Hybrid PAPR Technique for 5G Waveforms

Non-orthogonal multiple access(NOMA)is a strong contender multicarrier waveform technique for the fth generation(5G)communication system.The high peak-to-average power ratio(PAPR)is a serious concern in designing the NOMA waveform.However,the arrangement of NOMA is different from the orthogonal frequency division multiplexing.Thus,traditional reduction methods cannot be applied to NOMA.A partial transmission sequence(PTS)is commonly utilized to minimize the PAPR of the transmitting NOMA symbol.The choice phase aspect in the PTS is the only non-linear optimization obstacle that creates a huge computational complication due to the respective non-carrying sub-blocks in the unitary NOMA symbol.In this study,an efcient phase factor is proposed by presenting a novel bacterial foraging optimization algorithm(BFOA)for PTS(BFOA-PTS).The PAPR minimization is accomplished in a two-stage process.In the initial stage,PTS is applied to the NOMA signal,resulting in the partition of the NOMA signal into an act of sub-blocks.In the second stage,the best phase factor is generated using BFOA.The performance of the proposed BFOA-PTS is thoroughly investigated and compared to the traditional PTS.The simulation outcomes reveal that the BFOA-PTS efciently optimizes the PAPR performance with inconsequential complexity.The proposed method can signicantly offer a gain of 4.1 dB and low complexity compared with the traditional OFDM.

A KIND OF PAPR REDUCTION METHOD BASED ON PRUNING WPM AND PTS TECHNOLOGY

Wavelet packet multicarrier system gains widespread concern because of its better resistance performance to Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI), as well as the higher spectrum efficiency. However, multicarrier system has a high Peak to Average Power Ratio (PAPR), which will lead to many problems such as lower system performance. In order to solve the problem, a kind of PAPR reduction method based on pruning Wavelet Packet Modulation (WPM) and Partial Transmit Sequences (PTS) technology is proposed in this paper, through proper pruning of the full-tree structure of wavelet packet modulation in the PTS technology to reduce the number of nodes in the system, and finally improve the reduction effect of PAPR. Simulation results show that when Complementary Cumulative Distribution Function (CCDF) is 10 -3 , PTS based on pruning WPM compared with PTS technique and pruning technique has improved about 1 dB and 1.5 dB, which will not affect the system's Bit Error Rate (BER) performance in the wavelet packet multicarrier system.

A correlation OPTS algorithm for reducing peak to average power ratio of FBMC-OQAM systems

A correlation overlapping partial transmit sequence(C-OPTS) algorithm is proposed to solve the issue of high complexity of overlapping partial transmit sequence(OPTS) algorithm in suppressing the peak to average power ratio(PAPR) of filter bank multicarrier-offset quadrature amplitude modulation(FBMC-OQAM) signals.The V subblocks in partial transmit sequence(PTS) are regrouped into U combinations according to the correlation coefficient p,and overlapping subblocks are allowed between adjacent groups.The search starts from the first group and sets the phase factors of the subsequent groups to 1.When the phase factors of the non-overlapping subblocks in the first group are determined,the subsequent groups are searched in turn to determine their respective phase factors.Starting from the second data block,the data overlapped with it should be taken into account when determining its optimal phase factor vector.Theoretical analysis and simulation results indicate that compared with the OPTS algorithm,the proposed algorithm can significantly reduce the computational complexity at the cost of slight deterioration of PAPR performance.Meanwhile,compared with the even-odd iterative double-layers OPTS(ID-OPTS) algorithm,it can further reduce the complexity and obtain a better PAPR suppression effect.

Discrimination between Demodex folliculorum(Acari:Demodicidae) isolates from China and Spain based on mitochondrial cox1 sequences

For a long time,classification of Demodex mites has been based mainly on their hosts and phenotypic characteristics.A new subspecies of Demodex folliculorum has been proposed,but not confirmed.Here,cox1 partial sequences of nine isolates of three Demodex species from two geographical sources(China and Spain) were studied to conduct molecular identification of D.folliculorum.Sequencing showed that the mitochondrial cox1 fragments of five D.folliculorum isolates from the facial skin of Chinese individuals were 429 bp long and that their sequence identity was 97.4%.The average sequence divergence was 1.24% among the five Chinese isolates,0.94% between the two geographical isolate groups(China(5) and Spain(1)),and 2.15% between the two facial tissue sources(facial skin(6) and eyelids(1)).The genetic distance and rate of third-position nucleotide transition/transversion were 0.0125,2.7(3/1) among the five Chinese isolates,0.0094,3.1(3/1) between the two geographical isolate groups,and 0.0217,4.4(3/1) between the two facial tissue sources.Phylogenetic trees showed that D.folliculorum from the two geographical isolate groups did not form sister clades,while those from different facial tissue sources did.According to the molecular characteristics,it appears that subspecies differentiation might not have occurred and that D.folliculorum isolates from the two geographical sources are of the same population.However,population differentiation might be occurring between isolates from facial skin and eyelids.