scholarly journals Filtered orthogonal frequency division multiplexing for improved 5G systems

2021 ◽  
Vol 10 (4) ◽  
pp. 2079-2087
Author(s):  
Ammar A. Sahrab ◽  
Alaa Doohee Yaseen
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Human Life ◽  
Sinc Function ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Error Vector Magnitude ◽  
Band Emission ◽  
Fifth Generation ◽  
Power Spectral ◽  
High Spectral Efficiency

Wireless communications became an integrated part of the human life. Fifth generation (5G) is the modern communication which provides enhanced mobile broadband (eMBB), ultra reliable low latency communications (URLLC), and massive machine type communication (mMTC). Thus, 5G have to provide coverage to multi-numerology devices, therefore, modulation and access schemes are suggested in the literature such as cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) and filtered OFDM (f-OFDM). CP-OFDM suffers from the high out of band emission which limited the multi-numerology applications. In f-OFDM, the out of band emission can be suppressed to an accepted extent such that different numerologies can be coexisting. On the other hand, f-OFDM can be more improved by using a proper filtering approach. In this paper three different filters are suggested based windowed-sinc function; Hanning, Hamming, and Blackman. Simulation results show that the proposed filters are promising for high spectral efficiency and out of band emission rejection. Furthermore, the bit error rate, error vector magnitude, and power spectral density are further improved with respect to CP-OFDM scheme but some trade-off is present. Overall, the suggested windowed-sinc filters are outperforming the traditional CP-OFDM. As a conclusion, the suggested windnowed-sinc filters have no limitations on the modulation order or the number of subcarriers utilized in the system.

scholarly journals 5G Multi-Carrier Modulation Techniques: Prototype Filters, Power Spectral Density, and Bit Error Rate Performance

2021 ◽  
Author(s):  
Shaik Nilofer ◽  
Praveen Kumar Malik
Keyword(s):  
Wireless Communication ◽  
Spectral Density ◽  
Power Spectral Density ◽  
Bit Error Rate ◽  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Fifth Generation ◽  
Power Spectral

Abstract In recent years for fourth-generation wireless communication systems Orthogonal Frequency Division Multiplexing (OFDM) multi-carrier modulation (MCM) has been an excellent choice. But for the fifth-generation air interface, the choice of multi-carrier modulation remains the biggest challenge. A potential multi-carrier modulation or candidate waveforms are required for the design of the physical layer. This paper highlights the merits and limitations of new candidate waveforms for fifth-generation wireless communication system. This paper mainly reviews Orthogonal frequency division multiplexing, Filtered-OFDM (F-OFDM), Universal Frequency Division Multiplexing (UFMC), Filtered Bank Multi-Carrier Modulation (FBMC), and Generalized Frequency Division Multiplexing (GFDM). This paper mainly reviews some of the comparisons of the parameters as power spectral density and bit error rate.

scholarly journals EVM Loss: A Loss Function for Training Neural Networks in Communication Systems

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1094
Author(s):  
Scott Stainton ◽  
Martin Johnston ◽  
Satnam Dlay ◽  
Paul Anthony Haigh
Keyword(s):  
Neural Networks ◽  
Loss Function ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Frequency Division Multiplexing ◽  
Efficiency Gain ◽  
Frequency Division ◽  
Error Vector Magnitude ◽  
Modulation Formats ◽  
Complex Approach

Neural networks and their application in communication systems are receiving growing attention from both academia and industry. The authors note that there is a disconnect between the typical objective functions of these neural networks with regards to the context in which the neural network will eventually be deployed and evaluated. To this end, a new loss function is proposed and shown to increase the performance of neural networks when implemented in a communication system compared to previous methods. It is further shown that a ‘split complex’ approach used by many implementations can be improved via formalisation of the ‘concatenated complex’ approach described herein. Experimental results using the orthogonal frequency division multiplexing (OFDM) and spectrally efficient frequency division multiplexing (SEFDM) modulation formats with varying bandwidth compression factors over a wireless visible light communication (VLC) link validate the efficacy of the proposed method in a real system, achieving the lowest error vector magnitude (EVM), and thus bit error rate (BER), across all experiments, with a 5 dB to 10 dB improvement in the received symbols EVM overall compared to the baseline implementation, with bandwidth compressions down to 40% compared to OFDM, resulting in a spectral efficiency gain of 67%.

scholarly journals Research of the Influence of the Quadrature Components Mismatch on the Noise Immunity of OFDM and UFMC Signals

2021 ◽  
Vol 24 (1) ◽  
pp. 71
Author(s):  
A. Yu. Belousov ◽  
V. V. Khvorenkov
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Noise Immunity ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Error Vector Magnitude ◽  
Error Vector ◽  
Vector Magnitude

Метод непосредственной модуляции с использованием комплексных сигналов применяется при реализации сигнальных трактов передатчиков в базовых станциях систем сотовой связи. В процессе модуляции возникают рассогласования коэффициента усиления и фазы квадратурных составляющих сигнала. Рассогласование ухудшает модуль вектора ошибки (Error Vector Magnitude, EVM) в приемнике, что, в свою очередь, приводит к повышению частоты появления ошибочных битов (Bit Error Rate, BER). Качество принимаемого сигнала выражается в частоте появления битовых ошибок. Рассогласование амплитуды и фазы квадратурных составляющих является одним из важнейших факторов, вносящих наибольший вклад в амплитуду вектора ошибки, который необходимо исследовать.В статье приведено исследование влияния рассогласования квадратурных составляющих сигналов технологий OFDM (Orthogonal frequency-division multiplexing) и UFMC (universal filtered multi-carrier). Разработана модель передатчика, канала связи и приемника для сигналов OFDM и UFMC. Модель построена в програм­мной среде MatLab при помощи языка MatLab и представляет собой программную модель m-script.В ходе работы путем исследования имитационной модели изучена зависимость помехоустойчивости технологий путем изменения параметров канала связи, таких как амплитудное и фазовое рассогласование квадратурных составляющих сигнала, а также отношение сигнал/шум. Проведен сравнительный анализ таких параметров сигналов, как занимаемая полоса частот, пик-фактор, частота появления битов с ошибкой. По результатам исследования получены графики зависимости вероятности ошибки и пик-фактора сигнала от рассогласования квадратурных составляющих для двух технологий – OFDM и UFMC. Проведенное исследование позволяет выделить преимущества технологии UFMC, которые выражаются в спектральной эффективности, помехоустойчивости и уровне пик-фактора сигнала.

scholarly journals Development of a GFDM waveform with radio defined with software

2018 ◽  
Vol 1 (2) ◽  
pp. 282-292
Author(s):  
Daniel Ricardo Pérez-Riaño ◽  
Elkin Andrés Ducuara-Hernández ◽  
Luis Fernando Pedraza-Martínez
Keyword(s):  
Software Defined Radio ◽  
Orthogonal Frequency Division Multiplexing ◽  
Spectrum Analyzer ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Gnu Radio ◽  
Advantages And Disadvantages ◽  
Fifth Generation ◽  
Usrp N210

In this paper the performance of a Generalized Frequency Division Multiplexing waveform is evaluated when compared to an Orthogonal Frequency Division Multiplexing signal. For the development of the previous waveforms, the GNU radio software and the Software Defined Radio (SDR) equipment USRP N210 are used. Through a spectrum analyzer the power of both waveforms are measured and the Out-of-Band Radiation is analyzed. Then, the results obtained are compared and the advantages and disadvantages of the implementation of GFDM as a waveform within the fifth generation systems are exposed.

scholarly journals 5G F-OFDM Waveform Based Software-Defined Radio Technology

2021 ◽  
Vol 20 ◽  
pp. 68-80
Author(s):  
Dia Mohamad Ali ◽  
Zhraa Zuheir Yahya
Keyword(s):  
Software Defined Radio ◽  
Orthogonal Frequency Division Multiplexing ◽  
Hardware Implementation ◽  
Software Radio ◽  
Spectrum Efficiency ◽  
Practical Implementation ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Fifth Generation ◽  
Radio Technology

Filtered-orthogonal frequency division multiplexing (F-OFDM) is a quasi-orthogonal waveform candidate for the applications of the fifth generation (5G) communication system. In this study, an F-OFDM waveform with unequal sub-band sizes is proposed to improve the spectrum efficiency (SE) of the 5G system. The proposed waveform is modeled with the Blackman window-sinc filter and is developed based on the software-defined radio (SDR) technology for practical implementation. The result shows that the F-OFDM performance of the simulation and hardware implementation is approximately the same. The SE using the proposed F-OFDM waveform is 6% and 5.8% higher than the SE using the conventional OFDM waveform under the simulation in the LabVIEW NXG simulator and under the practical use in the universal software radio peripheral (USRP) platform, respectively.

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