scholarly journals The Research on Improved Companding Transformation for Reducing PAPR in Underwater Acoustic OFDM Communication System

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Jinqiu Wu ◽  
Gang Qiao ◽  
Xiaofei Qi
Keyword(s):  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Low Complexity ◽  
Underwater Acoustic Communication ◽  
Frequency Division ◽  
Underwater Acoustic ◽  
Simulation And Experiment ◽  
The Cost ◽  
Ber Performance

To solve the problem of the high peak-to-average power ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) for the underwater acoustic communication system, the paper offers a method of reducing PAPR which combines the amplitude limiting and the improved nonlinear transformation. Traditional amplitude limiting technique can reduce PAPR in OFDM system effectively, at the cost of reducing the bit error rate (BER). However the companding transformation has far less computation complexity than SLM or PTS technologies and can improve the BER performance compared to the amplitude limiting technique simultaneously. The paper combines these two kinds of techniques, takes full use of advantages of the two method, and puts forward a low-complexity scheme choosing parameters that are more appropriate to the underwater acoustic field, with the result of improved BER performance even in lower SNR. Both simulation and experiment results show that the new method which combines clipping and companding transformation can effectively reduce the PAPR in the underwater acoustic OFDM communication system and improve the BER performance simultaneously.

scholarly journals OFDM PAPR reduction for image transmission using improved tone reservation

2021 ◽  
Vol 11 (1) ◽  
pp. 416
Author(s):  
Zainab Noori Ghanim ◽  
Buthaina M. Omran
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Image Transmission ◽  
Low Complexity ◽  
Papr Reduction ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm System ◽  
Tone Reservation ◽  
The Cost

High peak to average power ration (PAPR) in orthogonal frequency division multiplexing (OFDM) is an important problem, which increase the cost and complexity of high power amplifiers. One of the techniques used to reduce the PAPR in OFDM system is the tone reservation method (TR). In our work we propose a modified tone reservation method to decrease the PAPR with low complexity compared with the conventional TR method by process the high and low amplitudes at the same time. An image of size 128×128 is used as a source of data that transmitted using OFDM system. The proposed method decrease the PAPR by 2dB compared with conventional method with keeping the performance unchanged. The performance of the proposed method is tested with several numbers of subcarriers; we found that the PAPR is reduced as the number of subcarriers decreased.

Implementation of an Impulse Noise Suppression Method in OFDM Underwater Acoustic Communication System

2011 ◽  
Vol 268-270 ◽  
pp. 1537-1542
Author(s):  
Wen Han Ma ◽  
Xiao Yi Hu ◽  
Li Yang Bai
Keyword(s):  
Shallow Water ◽  
Acoustic Communication ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Impulse Noise ◽  
Underwater Acoustic Communication ◽  
Ofdm System ◽  
Underwater Acoustic ◽  
Sea Trial ◽  
Ber Performance

This paper describes the characteristics of the impulse noise in the shallow water acoustic channel, and its influence on the bit error rate (BER) performance of the Orthogonal Frequency Division Multiplexing (OFDM) system. The simulation has been carried out to analyze the performance of the joint suppression of impulse noise in time and frequency domain in OFDM underwater acoustic communication system. Data processing of the actual sea trial in Xiamen Harbor shows that the method has some impressive effect on impulse noise in shallow water acoustic OFDM system, and improves the BER performance on different levels.

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.

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