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Design of multi-antenna relaying for OFDM in impulsive noise environment

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Digital Communications and Networks 2019年第3期5卷 189-195页

作者： Ahmed El-Mahdy MennaTullah Seraj-Eldin Professor in the Faculty of Information Engineering and Technology German University in Cairo Cairo Egypt The Faculty of Information Engineering and Technology German University in Cairo Cairo Egypt

A low-complexity multi-antenna relaying scheme is proposed for Orthogonal Frequency Division Multiplexing (OFDM) in the presence of Class-A Impulsive Noise (IN). One way and two way relaying are considered. The signal is transmitted and received by two terminal nodes, each with a single antenna in two time phases. In the proposed design, the processing at the relay consists of Maximal-Ratio Combining (MRC) or Power-based Selection Combining (PSC) for receive combining, Amplify and Forward (AF) for power scaling, and Space Time Block Coding (STBC) for transmit diversity. Channel State Information (CSI), Discrete Fourier Transform (DFT), and Inverse Discrete Fourier Transform (IDFT) are not needed. The Selective Mapping (SLM) technique is used at the transmitter to reduce the peak-to-average Power Ratio (PAPR) of the OFDM signal. Then, at the receiver, the clipping technique is used to reduce the impulses that result from the impulsive noise. The proposed system reduces the complexity of the conventional system, which uses multi-relay with a single antenna. Simulation results show that the Bit Error Rate (BER) of the proposed scheme outperforms that of the conventional scheme due to the diversity inherent in the proposed scheme.

关键词： Orthogonal frequency division multiplexing Impulsive noise Multi-antenna relay Reception combining Transmit diversity peak-to-average power ratio reduction techniques

PAPR Distribution Analysis at the Output of Nonlinear PAPR Reducers

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Journal of Signal and Information Processing 2012年第4期3卷 465-468页

作者： Désiré Guel Jacques Palicot SUPELEC/IETR Campus de Rennes Avenue de la Boulaie CS 47601 F-35576 Cesson-Sévigné cedex

Nonlinear PAPR reducers, such as clipping and companding techniques, are some simple methods used to reduce the peak-to-average Power Ratio (PAPR). In this paper, assuming that the baseband OFDM signal is characterized as a band-limited complex Gaussian process, we investigate the PAPR distribution of an OFDM signal when it is passed through a nonlinear PAPR reducer. The obtained PAPR distribution depends on the nonlinear function which characterizes the PAPR reducer. Later in this paper, we apply the obtained PAPR distribution in the clipping case. The comparisons made between the proposed distribution and that obtained thanks to computer simulations show good agreement.

关键词： Orthogonal Frequency Division Multiplexing (OFDM) peak-to-average Power Ratio (PAPR) Distribution Nonlinear PAPR Reducers

A new post-coding approach for PAPR reduction in DC-biased optical OFDM systems

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Optoelectronics Letters 2019年第4期15卷 302-305页

作者： Abbas Ali Sharifi Department of Electrical Engineering University of Bonab

The high peak-to-average power ratio(PAPR) is one of the main drawbacks in orthogonal frequency division multiplexing(OFDM) communication systems, which also exists in the optical OFDM(O-OFDM) systems. In this letter, a new approach based on the discrete Hartley transform(DHT) post-coding technique is proposed to reduce PAPR of an O-OFDM signal in visible light communication systems. The proposed method is compared with Walsh-Hadamard transform(WHT) and discrete cosine transform(DCT) techniques in terms of PAPR reduction and bit error rate(BER)performance. Experimental results indicate that the proposed DHT post-coding method remarkably reduces the PAPR of an OFDM signal for optical intensity modulated direct detection systems without any corruption in the BER performance.

关键词： peak-to-average power ratio(PAPR) optical OFDM(O-OFDM) discrete Hartley transform(DHT)

Reduction PAPR of OFDM Signals by Combining Grouped DCT Precoding with PTS

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Journal of Signal and Information Processing 2014年第4期5卷 135-142页

作者： Zhongpeng Wang Shoufa Chen School of Information and Electronic Engineering Zhejiang University of Science and Technology Hangzhou China State Key Laboratory of Millimeter Waves Southeast University Nanjing China

The high peak-to-average power ratio (PAPR) is one of the serious problems in the application of OFDM technology. In this paper, an improved partial transmit sequence (PTS) scheme based on combining the grouped discrete cosine transform (DCT) with PTS technique is proposed. In the proposed scheme, the adjacent partitioned data are firstly transformed by a DCT into new modified data. After that the proposed scheme utilizes the conventional PTS technique to further reduce the PAPR of the OFDM signal. The performance of the PAPR is evaluated using a computer simulation. The simulation results indicate that the proposed scheme may improve the PAPR performance compared with the conventional PTS scheme, the grouped DCT scheme, and original OFDM respectively.

关键词： Orthogonal Frquency-Division Multiplexing (OFDM) peak-to-average Power Ratio (PAPR) Partial Transmit Sequence (PTS) Discrete Cosine Transform (DCT)

OFDM Wireless Downhole Transmission Systems and Proposed SLM Method for PAPR Reduction

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Communications and Network 2014年第1期6卷 9-14页

作者： Renze Luo Yupu Dang Rui Li Jiao Yang Department of Well Tech China Oilfield Services Limited Beijing China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu China

At present, mud pulse transmission systems are widely used in downhole data transmission. But the systems are very low in transmission efficiency, only 5-10 bits/s, with very large anti-inter-symbol-interference (ISI). It cannot meet high requirements for high-speed transmission of modern logging system. The development of communication technology has laid some foundation for this requirement. For this purpose, the Orthogonal Frequency Division Multiplexing (OFDM) Wireless Downhole Transmission Systems are proposed for the first time because of their high transmission rate, anti-inter-symbol-interference (ISI), and high spectral efficiency, etc. Due to non-linear power amplifier (PA) of logging systems with limited dynamic range, the drawbacks of high peak-average power ratio (PAPR) may outweigh all the potential benefits of OFDM wireless downhole transmission systems. Selective mapping (SLM) method can reduce the PAPR of OFDM logging signals without distortion. But at the receiver, the conventional SLM method needs exact bits of side information (SI) to recover the data signal. The probability of erroneous SI detection has a significant influence on the error performance of the system. And individual transmissions of SI result in the reduction of bandwidth efficiency. To restore the exact data signal, our scheme codes the SI bits by linear block codes (LBC), and is easily decoded by syndrome decoding. And then the coding SI bits are superimposed onto the logging signals to omit SI bits transmission. The theory and simulation results show that the proposed method has better performance than the conventional one. Accordingly, the OFDM wireless downhole transmission systems can tackle the high PAPR problem, and highten the transmission rate of logging signals.

关键词： Orthogonal Frequency Division Multiplexing Wireless Downhole Transmission Systems Orthogonal Frequency Division Multiplexing (OFDM) Logging While Drilling (LWD) peak-to-average Power Ratio (PAPR) Selected Mapping (SLM)

A PTS Optimization Scheme with Superimposed Training for PAPR Reduction in OFDM System

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Communications and Network 2014年第2期6卷 97-104页

作者： Renze Luo Rui Li Xiaoqiong Wu Shuainan Hu Na Niu State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu Sichuan China Zhongshan Branch China Telecom Co. Ltd. Zhongshan Guangdong China

Partial Transmit Sequences (PTS) is an efficient scheme for peak-to-average Power Ratio (PAPR) reduction in Orthogonal Frequency Division Multiplexing (OFDM) system. It does not bring any signal distortion. However, its remarkable drawback is the high computational complexity. In order to reduce the computational complexity, currently many PTS methods have been proposed but with the cost of the loss of PAPR performance of the system. In this paper, we introduce an improved PTS optimization method with superimposed training. Simulation results show that, compared with conventional PTS, improved PTS scheme can achieve better PAPR performance while be implemented with lower computation complexity of the system.

关键词： Orthogonal Frequency Division Multiplexing (OFDM) peak-to-average Power Ratio (PAPR) Partial Transmit Sequences (PTS) Superimposed Training

不同叠加训练序列PTS降低PAPR性能比较

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计算机技术与发展 2014年第5期24卷 113-116页

作者：张杰罗仁泽党煜蒲牛娜李芮杨娇西南石油大学四川成都610500

部分传输序列(PTS)能有效降低正交频分复用(OFDM)系统的峰均功率比(PAPR),但是其存在降低性能有限和边带信息占用频谱资源的问题。文中在传统PTS方法的基础上,基于叠加训练序列PTS降低PAPR的方法,分析了叠加不同训练序列、不同训练序列... 详细信息

部分传输序列(PTS)能有效降低正交频分复用(OFDM)系统的峰均功率比(PAPR),但是其存在降低性能有限和边带信息占用频谱资源的问题。文中在传统PTS方法的基础上,基于叠加训练序列PTS降低PAPR的方法,分析了叠加不同训练序列、不同训练序列作相位旋转因子及功率分配因子对降低PAPR性能的影响。仿真结果表明:叠加自相关性较好的训练序列,降低PAPR的能力更强;不同训练序列作相位旋转因子时,对降低PAPR的效果影响不大;采用Hadama码、功率分配因子大于0.15时,降低PAPR的能力增强。该方法中的训练序列,不仅可以用于同步﹑信道估计,而且可以降低PAPR,并提高系统频谱利用率。

关键词：正交频分复用部分传输序列峰均功率比叠加训练序列频谱利用率 Orthogonal Frequency Division Multiplexing (OFDM) Partial Transmit Sequences (PTS) peak-to-average Power Ratio (PAPR)