scholarly journals PAPR Reduction of FBMC by Clipping and Its Iterative Compensation

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Zsolt Kollár ◽  
Péter Horváth
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Spectral Characteristics ◽  
Average Power ◽  
Real Life ◽  
Modulation Scheme ◽  
Physical Layers ◽  
Filter Bank Multicarrier ◽  
Transmitted Signal ◽  
Noise Cancelation

Physical layers of communication systems using Filter Bank Multicarrier (FBMC) as a modulation scheme provide low out-of-band leakage but suffer from the large Peak-to-Average Power Ratio (PAPR) of the transmitted signal. Two special FBMC schemes are investigated in this paper: the Orthogonal Frequency Division Multiplexing (OFDM) and the Staggered Multitone (SMT). To reduce the PAPR of the signal, time domain clipping is applied in both schemes. If the clipping is not compensated, the system performance is severely affected. To avoid this degradation, an iterative noise cancelation technique, Bussgang Noise Cancelation (BNC), is applied in the receiver. It is shown that clipping can be a good means for reducing the PAPR, especially for the SMT scheme. A novel modified BNC receiver is presented for SMT. It is shown how this technique can be implemented in real-life applications where special requirements must be met regarding the spectral characteristics of the transmitted signal.

scholarly journals Palm Date Leaf Clipping: A New Method to Reduce PAPR in OFDM Systems

Information ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 190 ◽  
Author(s):  
Brahim Bakkas ◽  
Reda Benkhouya ◽  
Idriss Chana ◽  
Hussain Ben-Azza
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Average Power ◽  
Papr Reduction ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Leaf Clipping ◽  
Hyperbolic Cosine ◽  
Transmitted Signal

Orthogonal frequency division multiplexing (OFDM) is the key technology used in high-speed communication systems. One of the major drawbacks of OFDM systems is the high peak-to-average power ratio (PAPR) of the transmitted signal. The transmitted signal with a high PAPR requires a very large linear range of the Power Amplifier (PA) on the transmitter side. In this paper, we propose and study a new clipping method named Palm Clipping (Palm date leaf) based on hyperbolic cosine. To evaluate and analyze its performance in terms of the PAPR and Bit Error Rate (BER), we performed some computer simulations by varying the Clipping Ratio (CR) and modulation schemes. The obtained results show that it is possible to achieve a gain of between 7 and 9 dB in terms of PAPR reduction depending on the type of modulation. In addition, comparison with several techniques in terms of PAPR and BER shows that our method is a strong alternative that can be adopted as a PAPR reduction technique for OFDM-based communication systems.

scholarly journals BCH codes in UFMC: A new contender candidate for 5G communication systems

2021 ◽  
Vol 10 (2) ◽  
pp. 904-910
Author(s):  
Ghasan Ali Hussain ◽  
Lukman Audah
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Error Correcting Codes ◽  
Bch Codes ◽  
Fourth Generation ◽  
Bch Code ◽  
Modulation Scheme ◽  
Ofdm System ◽  
Lte Advanced

Nowadays, fifth generation (5G) wireless network is considered one of the most important research topics in wireless industry and it will be substituting with fourth generation (4G) in several aspects. Although the robustness of orthogonal frequency division multiplexing (OFDM) system against channel delays which is the reason behind using it in LTE/LTE Advanced however, it is suffering from high peak to average power ration (PAPR) and out of band side lobes. So, universal filtered multi-carrier (UFMC) technique is considered a new modulation scheme for 5G wireless communication system to overcome on the common OFDM demits. In contrast, to achieve reliable data transmission in digital communication systems, using error correcting codes are considered an essential over noisy channels. In this paper, BCH code has been used for UFMC system over AWGN. The results showed that using BCH codes in UFMC contributed in enhancing BER performance while could decreasing both of PAPR and OOBE values better than conventional OFDM system.

Peak-to-Average Power Ratio Reduction for Acoustic Orthogonal Frequency Division Multiplexing Systems

2010 ◽  
Vol 44 (4) ◽  
pp. 30-41 ◽  
Author(s):  
Guillem Rojo ◽  
Milica Stojanovic
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multipath Propagation ◽  
Average Power ◽  
Gradient Algorithm ◽  
High Rate ◽  
Modulation Scheme ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division

AbstractOrthogonal frequency division multiplexing (OFDM) is an appealing modulation scheme for high-rate underwater acoustic communications that are challenged by multipath propagation. However, it has a drawback in the large peak-to-average power ratio (PAR). Techniques for PAR reduction have been extensively studied for radio communication systems. Although these techniques are applicable to acoustic systems, we take a different approach that aims to capitalize on the fundamental differences between the acoustic and the radio systems; namely, the fact that acoustic transmissions are inherently band limited. We extend the tone reservation technique to the out-of-band carriers and design efficient methods for constructing OFDM signals with lower PAR. Two approaches are investigated, one based on a gradient algorithm and another that uses random sequences. Simulation results show that our techniques can provide PAR reduction without the loss in data rate.

scholarly journals Análisis de la técnica UFMC en un canal multitrayecto y usando estimación de canal

2021 ◽  
Vol 9 (17) ◽  
pp. 26-39
Author(s):  
Hugo Wladimir Iza Benítez ◽  
Diego Javier Reinoso Chisaguano
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Filter Bank ◽  
Estimation Method ◽  
Wireless Communication Systems ◽  
Ofdm Systems ◽  
Matlab Simulation ◽  
Fifth Generation ◽  
Power Spectral ◽  
Filter Bank Multicarrier

UFMC (Universal Filtered Multi-Carrier) is a novel multi-carrier transmission technique that aims to replace the OFDM (Orthogonal Frequency Division Multiplexing) modulation technique for fifth generation (5G) wireless communication systems. UFMC, being a generalization of OFDM and FBMC (Filter Bank Multicarrier), combines the advantages of these systems and at the same time avoids their main disadvantages. Using a Matlab simulation, this article presents an analysis of the robustness of UFMC against fading effects of multipath channels without using a CP (cyclic prefix). The behavior of the UFMC system is analyzed in terms of the PSD (Power Spectral Density), BER (Bit Error Rate) and MSE (Mean Square Error). The results show that UFMC reduces the out-band side lobes produced in the PSD of the processed signal. Also, it is shown that the pilot-assisted channel estimation method applied in OFDM systems can also be applied in UFMC systems.

FBMC OQAM: novel variant of OFDM

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shiv Om Tiwari ◽  
Rajeev Paulus
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Data Transfer ◽  
Average Power ◽  
Hybrid Technique ◽  
Filter Bank Multicarrier ◽  
Novel Variant ◽  
Good Technique ◽  
Pass Through ◽  
Papr Performance ◽  
Better Than

Abstract Orthogonal frequency division multiplexing (OFDM) revolutionizes the transmission technologies, including, optical as well as wireless communication. In OFDM the orthogonal nature of carriers makes it very good technique for data transfer. Still the out-of-band (OOB) radiation in OFDM leads to inter symbol interference (ISI) and bit error rate (BER) goes down. Moreover amplitude variations of the subcarriers lead to power variations and peak-to-average power ratio (PAPR) problem. To overcome these issues a novel filter bank multicarrier (FBMC) scheme is proposed, where each carrier is allowed to pass through to a separate filter and orthogonality among subcarriers is relaxed. Thus FBMC has better OOB and PAPR performance. In this work, we also have evaluated the PAPR performance by the simulation results. For the improvement of PAPR nonlinear companding scheme along with clipping is presented. The hybrid technique (clipping + companding) parameters are set in such a way that PAPR is reduced while signal power remains constant. Results are also compared with recent methods and it has been found that the proposed technique preforms better than other chosen techniques.

BER Improvement in OFDM Systems Using Wavelet Transform Based on Kalman Filter

2020 ◽  
pp. 102-124
Author(s):  
Sajjan Singh
Keyword(s):  
Kalman Filter ◽  
Wavelet Transform ◽  
Fading Channels ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Performance Enhancement ◽  
Average Power ◽  
Discrete Wavelet ◽  
Rate Analysis

Orthogonal frequency division multiplexing (OFDM) is an efficient method of data transmission for high speed communication systems over multipath fading channels. However, the peak-to-average power ratio (PAPR) is a major drawback of multicarrier transmission systems such as OFDM is the high sensitivity of frequency offset. The bit error rate analysis (BER) of discrete wavelet transform (DWT)-OFDM system is compared with conventional fast Fourier transform (FFT)-OFDMA system in order to ensure that wavelet transform based OFDMA transmission gives better improvement to combat ICI than FFT-based OFDMA transmission and hence improvement in BER. Wavelet transform is applied together with OFDM technology in order to improve performance enhancement. In the proposed system, a Kalman filter has been used in order to improve BER by minimizing the effect of ICI and noise. The obtained results from the proposed system simulation showed acceptable BER performance at standard SNR.

scholarly journals A Hybrid PAPR Reduction Method Based on SLM and Multi-Data Block PTS for FBMC/OQAM Systems

Information ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 246 ◽  
Author(s):  
Han Wang
Keyword(s):  
Communication Systems ◽  
Filter Bank ◽  
Reduction Method ◽  
Average Power ◽  
Data Block ◽  
Papr Reduction ◽  
Wireless Communication Systems ◽  
Transmission Scheme ◽  
Filter Bank Multicarrier ◽  
Selective Mapping

The filter bank multicarrier employing offset quadrature amplitude modulation (FBMC/OQAM) is a candidate transmission scheme for 5G wireless communication systems. However, it has a high peak-to-average power ratio (PAPR). Due to the nature of overlapped signal structure of FBMC/OQAM, conventional PAPR reduction schemes cannot work effectively. A hybrid PAPR reduction scheme based on selective mapping (SLM) and multi data block partial transmit sequence (M-PTS) methods is proposed for FBMC/OQAM signals in this paper. Different from the simple SLM-PTS method, the proposed hybrid algorithm takes into account the overlapping effect of multiple adjacent data blocks on its PTS process. From simulation results, it can be obtained that the proposed method can offer a significant PAPR reduction performance improvement compared with the SLM, PTS and SLM-PTS methods. The proposed method can effectively reduce the PAPR in FBMC/OQAM systems.

scholarly journals ICI Cancellation in OFDM Systems by Frequency Offset Reduction

2014 ◽  
Vol 513-517 ◽  
pp. 3987-3991
Author(s):  
Naveed Ur Rehman ◽  
Lei Zhang ◽  
Muhammad Zahid Hammad ◽  
Emmanuel Anania Mwangosi
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Video Data ◽  
Modulation Scheme ◽  
Ofdm Systems ◽  
Receiver Side ◽  
High Data ◽  
Redundant Data ◽  
Wide Range

The rapid growth within the field of digital communication during the recent years expanded the need for high-speed data transmission to support a wide range of services such as: video, data and voice in wireless communication systems, etc. Orthogonal frequency division multiplexing (OFDM) and a multicarrier modulation scheme are employed to achieve the high data rates. Since OFDM is very much sensitive to carrier frequency offsets, which cause the Inter-carrier Interference (ICI) leads to mitigation of this ICI is necessary. The objectives of this paper are to, proposed an efficient ICI self-cancellation scheme to mitigate the effect of ICI on OFDM systems. For this purpose, a redundant data is transmitted onto adjacent sub-carriers such that the ICI between adjacent sub-carriers cancels out at the receiver side. One data symbol is modulated into a group of adjacent sub carriers with a group of weighting coefficients. At the receiver side, the received signals are linearly combined on these sub carriers with proposed coefficients. The residual ICI contained in the received signals can then be further reduced. This study provides significant carrier-to-interference power ratio (CIR) improvement, which has been studied theoretically and supported by simulations. Since no channel equalization is required to reduce ICI, so the proposed scheme doesnt increase the system complexity.

scholarly journals An Efficient Adaptive Technique with Low Complexity for Reducing PAPR in OFDM-Based Cognitive Radio

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Hefdhallah Sakran ◽  
Omar Nasr ◽  
Mona Shokair
Keyword(s):  
Cognitive Radio ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Low Complexity ◽  
Papr Reduction ◽  
Modulation Scheme ◽  
Ofdm Systems ◽  
Cpu Time ◽  
Reduction Techniques ◽  
Selective Mapping

Cognitive radio (CR) is considered nowadays as a strong candidate solution for the spectrum scarcity problem. On standards level, many cognitive radio standards have chosen Non-Contiguous Orthogonal Frequency Division Multiplexing (NC-OFDM) as their modulation scheme. Similar to OFDM, NC-OFDM suffers from the problem of having a high Peak to Average Power Ratio (PAPR). If not solved, either the transmitted signal will be distorted, which will cause interference to primary (licensed) users, or the effeciency of the power amplifier will be seriously degraded. The effect of the PAPR problem in NC-OFDM based cognitive radio networks is worse than normal OFDM systems. In this paper, we propose enhanced techniques to reduce the PAPR in NC-OFDM systems. We start by showing that combining two standard PAPR reduction techniques (interleaver-based and selective mapping) results in a lower PAPR than using them individually. Then, an “adaptive number of interleavers” will be proposed that achieves the same performance of conventional interleaver-based PAPR reduction while reducing the CPU time by 41.3%. Finally, adaptive joint interleaver with selective mapping is presented, and we show that it gives the same performance as conventional interleaver-based technique, with reduction in CPU time by a factor of 50.1%.

scholarly journals Number of subcarrier filter coefficients in GFDM system: effect on performance

Ingenius ◽  
2019 ◽  
pp. 53-61
Author(s):  
Randy Verdecia Peña ◽  
Humberto Millán Vega
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Modulation Scheme ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Transmission Scheme ◽  
System Effect ◽  
Simple Method ◽  
Multicarrier Transmission ◽  
Prototype Filter

Generalized Frequency Division Multiplexing (GFDM) is a non-orthogonal multicarrier transmission scheme proposed for fifth (5G) and future generation wireless networks. Due to its attractive properties, it has been recently discussed as a candidate waveform for the future wireless communication systems. GFDM is introduced as a generalized form of the widely used Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme and it uses only one cyclic prefix (CP) for a group of symbols. The main focus of this work is to present like impact on the system performance the coefficient quantity of the subcarrier filter. A simple method for the computation of the coefficients of the prototype filter is employed. Besides, it is presented a structure for the GFDM by taking advantage of the arrangement in the modulation matrix. We evaluated the Bit Error Rate (BER) using the receiver models presented in this work. The results showed that the BER is affected according to the coefficients quantity of the prototype filter. Based on the obtained results, the coefficients quantity has a relation with the number of time slots of the GFDM system.

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