scholarly journals ECCM Schemes against Deception Jamming Using OFDM Radar with Low Global PAPR

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2071
Author(s):  
Xinhai Wang ◽  
Gong Zhang ◽  
Xiangmin Wang ◽  
Qingqing Song ◽  
Fangqing Wen
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Optimization Problem ◽  
Average Power ◽  
Doppler Spectrum ◽  
Frequency Division ◽  
Ofdm Symbol ◽  
Alternating Direction ◽  
Parseval’S Theorem ◽  
Joint Range ◽  
Huge Challenge

In this paper, a type of effective electronic counter-countermeasures (ECCM) technique for suppressing the high-power deception jamming using an orthogonal frequency division multiplexing (OFDM) radar is proposed. Concerning the velocity deception jamming, the initial phases of the pulses transmitted in a coherent processing interval (CPI) are designed to minimize the jamming power within a specific range, forming a notch around the jamming in the Doppler spectrum. For the purpose of suppressing the range deception jamming and the joint range-velocity deception jamming, the phase codes of the subcarriers belonging to the OFDM pulses are optimized to minimize the jamming power, distributing some specific bands in the range and the range-velocity domain, respectively. According to Parseval’s theorem, the phase encoding, acting as the coding manner of the OFDM subcarriers can ensure that the energy of each OFDM symbol stays the same. It is worth noticing that the phase codes of the OFDM subcarriers can influence the peak-to-average power ratio (PAPR). Thus, an optimization problem is formulated to optimize the phase codes of the subcarriers under the constraint of global PAPR, which can regulate the PAPRs of multiple OFDM symbols at the same time. The proposed problem is non-convex; therefore, it is a huge challenge to tackle. Then we present a method named by the phase-only alternating direction method multipliers (POADMM) to solve the aforementioned optimization problem. Some necessary simulation results are provided to demonstrate the effectiveness of the proposed radar signaling strategy

scholarly journals An Improved GreenOFDM Scheme for PAPR Reduction

Telecom ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 196-210
Author(s):  
Jorge Luis Gulfo Monsalve ◽  
Laurent Ros ◽  
Jean-Marc Brossier ◽  
Denis Mestdagh
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Fourier Transforms ◽  
Average Power ◽  
Reduction Technique ◽  
Papr Reduction ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm Symbol ◽  
Papr Performance ◽  
The One

In this paper, we propose an improvement to a recent Peak-to-Average Power Ratio (PAPR) reduction technique for Orthogonal Frequency Division Multiplexing (OFDM), the GreenOFDM. This technique, which is inspired by SeLected Mapping (SLM), generates several waveform candidates using a given number of Inverse Fast Fourier Transforms (IFFT), and selects the one with the lowest PAPR for the transmission of the OFDM symbol. For U IFFTs, GreenOFDM provides better PAPR reduction capabilities than SLM-OFDM as it increases the number of waveform candidates from U (for SLM-OFDM) to U2/4. In this work, we propose an extension of the GreenOFDM that further increases the number of waveform candidates by a factor of 4 (from U2/4 to U2), or equivalently reduces by a factor of 2 the number of IFFTs for a same PAPR performance. Compared to SLM-OFDM, the improved GreenOFDM technique reduces the complexity by requiring only the square-root of the number of IFFTs for a same PAPR reduction performance. Furthermore, exciting methods for additional complexity reduction are also implemented and discussed.

scholarly journals Advantages of Spectrally Efficient Frequency Division Multiplexing Over Orthogonal Frequency Division Multiplexing

2020 ◽  
Vol 9 (8) ◽  
pp. 238-244
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Sphere Decoder ◽  
Symbol Rate ◽  
Transmission Length ◽  
Spectrally Efficient ◽  
The Impact

An analysis on Spectrally Efficient Frequency Division Multiplexing (SEFDM) is contrast with Orthogonal Frequency Division Multiplexing (OFDM) considering the impact on Peak to Average Power Ratio (PAPR) and nonlinearities within fibre. With respect to OFDM the sub-carriers in SEFDM signals are compressed adjacent to each other at a rate of frequency lesser than the symbol rate. At the receiver end we have utilized the Sphere Decoder which is used to recover the data to remunerate the Interference created by the compressed signals (ICI) faced in the system. This research shows the advantages by using SEFDM and evaluates its achievement. PAPR. when compared with OFDM, while effects of non-linear fibres are considered. The use of various formats of modulation going from 4-QAM to 32-QAM, shows that the SEFDM signals have a noteworthy increment in the transmission length with respect to ordinary signals.

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 Spectral Efficiency of FBMC Over OFDM System

2019 ◽  
Vol 9 (2S3) ◽  
pp. 235-237
Keyword(s):  
Spectral Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Filter Bank ◽  
Average Power ◽  
Primary Objective ◽  
Mobile Environments ◽  
Frequency Division ◽  
Doppler Shifts ◽  
Wireless Broadband ◽  
High Spectral Efficiency

Significant wireless broadband technology used in various cellular standards is Orthogonal Frequency Division Multiplexing (OFDM) which will make use of Multi Carrier Modulated (MCM) systems. Even though OFDM has numerous advantages, it is hard to employ OFDM for complex networks. It is very hard to establish synchronization in mobile environments as it is difficult to predict the Doppler shifts of different users, which results in inter carrier interference (ICI). Further, filters associated with OFDM carrier have comparatively large sidebands which outcomes in Out of Band (OOB) radiations. Insufficient spectral usage is provided by CP-OFDM by using more guard band. So the problems caused by traditional OFDM/CP-OFDM can be answered by employing a new system termed as Filter Bank Multi Carrier (FBMC) System. It is a form of MCM and it can be considered as an advanced cyclic-prefix (CP-OFDM). In OFDM, whole band gets filtered while in FBMC, each sub carrier band is independently filtered. The primary objective of this work is to relate the performance of 5G modulation technique such as FBMC against OFDM and to suggest an ideal waveform for 5G communication in regard to high spectral efficiency, spectral density, BER and less Peak to Average Power Ratio (PAPR).

Dynamic Hyperchaotic Key Generation Using Optical Orthogonal Frequency Division Multiplexing-based Visible Light Communication Networks

2021 ◽  
Author(s):  
Mohammed Alresheedi ◽  
YAHYA AL-MOLIKI ◽  
Yahya Al-Harthi ◽  
Ali Alqahtani
Keyword(s):  
Visible Light ◽  
Communication Networks ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Visible Light Communication ◽  
Frequency Division Multiplexing ◽  
Key Generation ◽  
Frequency Division ◽  
Degree Of Protection ◽  
Communication Time

Abstract This paper introduces an optical orthogonal frequency division multiplexing (OFDM)-based hyperchaotic key generation encryption approach that can improve confidentiality in visible light communication (VLC) networks. Using a hyperchaotic four-dimensional method, the bipolar real-valued OFDM signal can be used for constructing dynamic cypher keys modified at every frame over the communication time, resulting in a superior degree of protection against statistical and correlation attacks. In accordance with our findings, this approach decreases the ratio of peak-to-average power of the transmitted signal, and enhances the bit error rate efficiency and secrecy capacity of the OFDM-based VLC network, which improves confidentiality.

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