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.

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 Multicarrier Waveform Harmonization and Complexity Analysis for an Efficient 5G Air Interface Implementation

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
David Garcia-Roger ◽  
Sandra Roger ◽  
Josue Flores de Valgas ◽  
Jose F. Monserrat
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Filter Bank ◽  
Hardware Implementation ◽  
Complexity Analysis ◽  
Model Complexity ◽  
Component Reuse ◽  
Fifth Generation ◽  
Air Interface ◽  
Filter Bank Multicarrier ◽  
Configurable Hardware

The coexistence of multiple air interface variants in the upcoming fifth generation (5G) wireless technology remains a matter of ongoing discussion. This paper focuses on the physical layer of the 5G air interface and provides a harmonization solution for the joint implementation of several multicarrier waveform candidates. Waveforms based either on cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) or on filter bank multicarrier (FBMC) are first presented through a harmonized system model. Complexity comparisons among five different waveforms are provided. Then, the complexity of a proposed configurable hardware implementation setup for waveform transmission and reception is evaluated. As a result, the harmonized transmitter and receiver exhibit 25–40% and 15–25% less complexity in floating-point operations, respectively, in comparison to two standalone implementations of the most complex waveform instances of the CP-OFDM and FBMC families. This highlights the similarities between both families and illustrates the component reuse advantages associated with the proposed harmonized solution.

scholarly journals Design of an Adaptive Predistorter for Solid State Power Amplifier in Wireless OFDM Systems

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Rui J. P. de Figueiredo ◽  
Lin Fang ◽  
Byung Moo Lee
Keyword(s):  
Performance Improvement ◽  
Power Amplifier ◽  
Communication Systems ◽  
Power Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Wireless Communication Systems ◽  
Ofdm Systems ◽  
High Power Amplifier ◽  
Ofdm Signals

Orthogonal frequency division multiplexing (OFDM) is a powerful modulation choice for wideband wireless communication systems. However, its high peak-to-average power ratio greatly limits the high power amplifier (HPA) power efficiency. Here, we present the design of an adaptive predistorter to compensate the distortion caused by the HPA. Specifically, we deal with the implementation issue of the proposed predistorter in Lee and de Figueiredo's work (2006). The performance improvement by predistorter is verified by both floating-point simulation and fixed-point simulation, where the latter includes the distortion effects from the hardware. The bit widths for OFDM signals, ADC, and DAC are evaluated, and the bit width of 10 is shown to be sufficient for the hardware design.

scholarly journals Analytical bound for the CCDF of Crest Factor in NC-OFDM Systems

2017 ◽  
Vol 11 (4) ◽  
pp. 180
Author(s):  
Mohammed Y. Bendimerad ◽  
Fatima Debbat ◽  
Fethi T. Bendimerad
Keyword(s):  
Fading Channels ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Value Theory ◽  
Design Parameters ◽  
Wireless Communication Systems ◽  
Ofdm Systems ◽  
Crest Factor ◽  
Large Peak

Non-contiguous orthogonal frequency division multiplexing (NC-OFDM) is a promising framework for wireless communication systems due to OFDM characteristics like the spectral bandwidth efficiency, robustness to frequency selective fading channels, etc. However, it has been widely known that multicarrier signals generated by OFDM technique exhibit a large peak to average power ration (PAPR), one of the main impediment that has limited the applicability of OFDM systems. Several approaches are employed in literature to derive the PAPR distribution and thus try to reduce it in OFDM context, as Central limit theorem and modern extreme value theory. In new contexts like NC-OFDM systems when flexible access to spectrum is done with non-contiguous portions, the PAPR distribution remains generally unknown, and it is necessary to describe it, since this is one of the key design parameters. In this correspondence, we develop the PAPR bound expression in NC-OFDM context.

Experimental Demonstration for PAPR Reduction in OFDM System Using Partial-OSLM Technique

2018 ◽  
Vol 27 (07) ◽  
pp. 1850106 ◽  
Author(s):  
M. I. Al-Rayif ◽  
H. Seleem ◽  
A. Ragheb ◽  
S. Alshebeili
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Side Information ◽  
Average Power ◽  
Papr Reduction ◽  
Ofdm Systems ◽  
Power Spectral ◽  
Comparable Performance ◽  
4G Wireless ◽  
Selective Mapping

Orthogonal frequency division multiplexing (OFDM) modulation is proposed in 4G wireless communication systems, and is under consideration for the next generation 5G systems. This is due to the higher spectral efficiency (SE) and the better immunity to channel distortions. One of the shortcomings in OFDM is its high peak-to-average power ratio (PAPR). Several schemes have been proposed to reduce the PAPR in OFDM systems. This includes clipping, coding, and pre/post-distortion schemes with or without side information. In this paper, we experimentally demonstrate one of the most promising method, to mitigate the effect of PAPR, entitled the partial orthogonal selective mapping (POSLM). The experimental results show a comparable performance with respect to the simulation results in terms of PAPR reduction, power spectral density (PSD), and bit error rate (BER) metrics.

scholarly journals Channel Estimation Techniques for OFDM and UFMC Systems for 5G Communications

2019 ◽  
Vol 8 (2S8) ◽  
pp. 1776-1778
Keyword(s):  
Channel Estimation ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Wireless Communication Systems ◽  
Modulation Scheme ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Machine Type ◽  
Machine Type Communications ◽  
Simulation Results

In this paper, pilot-assisted techniques for channel estimation (CE) are simulated for Universal Filtered Multi-Carrier (UFMC) modulation scheme. UFMC aims at replacing orthogonal frequency division multiplexing (OFDM) and improves performance and robustness in the case of timefrequency misalignment. These techniques efficiently support Internet of Things (IoT) and massive machine type communications (mMTC), which are identified as challenges for 5G wireless communication systems (WCS). Pilot-aided techniques are adopted and applied to OFDM and UFMC. Simulation results are supplemented to compare the performance of UFMC systems with conventional CP-OFDM systems.

scholarly journals Robust Preamble-Based Timing Synchronization for OFDM Systems

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Yun Liu ◽  
Fei Ji ◽  
Hua Yu ◽  
Dehuan Wan ◽  
Fangjiong Chen ◽  
...  
Keyword(s):  
Fading Channels ◽  
Orthogonal Frequency Division Multiplexing ◽  
Carrier Frequency Offset ◽  
Estimation Method ◽  
Multipath Fading ◽  
New Method ◽  
Timing Synchronization ◽  
Ofdm Systems ◽  
Multipath Fading Channels ◽  
Timing Offset

This study presents a novel preamble-based timing offset estimation method for orthogonal frequency division multiplexing (OFDM) systems. The proposed method is robust, immune to the carrier frequency offset (CFO), and independent of the structure of the preamble. The performance of the new method is demonstrated in terms of mean square error (MSE) obtained by simulation in multipath fading channels. The results indicate that the new method significantly improves timing performance in comparison with existing methods.

scholarly journals Adaptive Blind Channel Estimation for MIMO-OFDM Systems Based on PARAFAC

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Ruo-Nan Yang ◽  
Wei-Tao Zhang ◽  
Shun-Tian Lou
Keyword(s):  
Channel Estimation ◽  
Cost Function ◽  
Orthogonal Frequency Division Multiplexing ◽  
Weighted Least Squares ◽  
Estimation Method ◽  
Blind Channel Estimation ◽  
Ofdm Systems ◽  
Blind Channel ◽  
Mimo Ofdm ◽  
The Cost

In order to track the changing channel in multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems, it is prior to estimate channel impulse response adaptively. In this paper, we proposed an adaptive blind channel estimation method based on parallel factor analysis (PARAFAC). We used an exponential window to weight the past observations; thus, the cost function can be constructed via a weighted least squares criterion. The minimization of the cost function is equivalent to the decomposition of third-order tensor which consists of the weighted OFDM data symbols. To reduce the computational load, we adopt a recursive singular value decomposition method for tensor decomposition; then, the channel parameters can be estimated adaptively. Simulation results validate the effectiveness of the proposed algorithm under diverse signalling conditions.

scholarly journals Hardware Prototyping and Modelling of Prototype Filter for FBMC

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Bircan Çalişir ◽  
Ayhan Akbal
Keyword(s):  
Communication Networks ◽  
Orthogonal Frequency Division Multiplexing ◽  
Filter Bank ◽  
Filter Design ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Mobile Telecommunication ◽  
Guard Band ◽  
Filter Bank Multicarrier ◽  
Band Limited

Filter bank multicarrier (FBMC) is one of the effective candidates for the fifth generation of wireless communication networks. 5G (5th-generation wireless systems) is accepted as the next major stage of mobile telecommunication technology. The extent of 5G will be expanded mobile broadband services to next-generation automobiles and connected machines. In particular, filter bank multicarrier with offset quadrature amplitude modulation (FBMC/OQAM) is determined as the future generation 5G air interface by researchers recently. Filter bank multicarrier (FBMC) is admitted as one of the alternative technologies for multicarrier modulation. Compared to orthogonal frequency-division multiplexing (OFDM), FBMC has better spectrum shape and supports mobility. Therefore, efficient hardware implementations have highly interested researchers. Cyclic prefix (CP) and guard band are used for orthogonal frequency-division multiplexing (OFDM) and this causes loss of spectral efficiency, but FBMC applications do not need CP and guard band. Due to the fact that FBMC has offset QAM (OQAM) and band-limited filtering features on each subcarrier, the need for CP and guard band is eliminated. In this paper, novel pipelined hardware architecture of the filter design of FBMC/OQAM modulator has been proposed.

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