Filtered Orthogonal Frequency Division Multiplexing: A Waveform Candidate for 5G (original) (raw)
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Filtered orthogonal frequency division multiplexing for improved 5G systems
10.11591/eei.v10i4.3119, 2021
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.
An Overview of Various Waveform Contenders Based on OFDM for 5G Communication
International Journal of Trend in Scientific Research and Development, 2018
The rollout of fifth generation(5G) wireless communication technology provides high spectral efficiency, high speed, greater density of users, high capacity, pseudo outdoor communication etc. In the year 2020, the data consumption is expected to increase 30% which cannot be supported by the current technologies such as 3G and 4G. The (4G) mobile communication uses Orthogonal Frequency Division Multiplexing (OFDM) technique in various systems like-Wi-MAX. Now as the technology is being advanced to 5G, there are some drawbacks of OFDM like-peak to average power ratio (PAPR), out of band emissions (OOB), and use of cyclic prefix (CP).In this paper, the drawbacks of Ofdm in Lte has been removed using the waveforms contenders like UFMC, FBMC, and GFDM overwhelmingly welcomed for the 5G air interface. applications of 5G are Internet of Things (IoT), Vehicle to Vehicle (V2V) communication, Machine to Any (M2X) communication.
International journal of engineering & technology, 2018
4G LTE communication system uses OFDM and for resource allocation control channels like PRACH is used. Around 6% bandwidth is getting used for this PRACH procedure and due to OFDM requirement of strict synchronization, short messaging become tedious and cause power wastage due to the control traffic for every message. The main challenge for 5G communications is to handle the transmission of extremely asynchronous data and control traffic in one go. Existing OFDM based systems have the drawback of very sensitive to the time and frequency offsets and in turn results in synchronization errors. To overcome this challenge, it has been adopted a new waveform based on Bi-orthogonal Frequency Division multiplexing (BFDM) which supports the Internet of Things (IoT) sporadic traffic. In this paper, BFDM principles, behaviour of BFDM under various channel conditions, Matlab simulation results pertaining to the performance of BFDM against the existing OFDM are discussed. The simulation results shows that the Symbol Error Rate of the BFDM system is less than the OFDM under time varying fading conditions such as Extended Pedestrian A (EPA), Extended Vehicular A (EVA), Extended Typical Urban(ETU) models.
Comparison of Various Waveform Contenders of 5G Wireless Communication Based on OFDM
International Journal of Trend in Scientific Research and Development, 2018
This paper presents an extensive and fair comparison among the most promising waveform contenders for the 5G air interface which includes-Filtered OFDM, Filter-bank multi carrier (FBMC), universal multi-carrier (UFMC) has been compared with OFDM in terms of spectral efficiency and rate using mat lab. The disadvantages of OFDM have been addressed and it has shown that (fofdm), (UFMC), (FBMC) could be a more effective solution. FBMC is a method for improving out of band (OOB) characteristics by filtering each subcarrier, it is also expected to improve the Inter-Carrier Interference (ICI) characteristics while UFMC is a method for improving OOB characteristics by filtering each block.
Filtered OFDM Systems, Algorithms, and Performance Analysis for 5G and Beyond
IEEE Transactions on Communications
Filtered orthogonal frequency division multiplexing (F-OFDM) system is a promising waveform for 5G and beyond to enable multi-service system and spectrum efficient network slicing. However, the performance for F-OFDM systems has not been systematically analyzed in literature. In this paper, we first establish a mathematical model for F-OFDM system and derive the conditions to achieve the interference-free one-tap channel equalization. In the practical cases (e.g., insufficient guard interval, asynchronous transmission, etc.), the analytical expressions for inter-symbol-interference (ISI), inter-carrier-interference (ICI) and adjacent-carrier-interference (ACI) are derived, where the last term is considered as one of the key factors for asynchronous transmissions. Based on the framework, an optimal power compensation matrix is derived to make all of the subcarriers having the same ergodic performance. Another key contribution of the paper is that we propose a multi-rate F-OFDM system to enable low complexity low cost communication scenarios such as narrow band Internet of Things (IoT), at the cost of generating intersubband-interference (ISubBI). Low computational complexity algorithms are proposed to cancel the ISubBI. The result shows that the derived analytical expressions match the simulation results, and the proposed ISubBI cancelation algorithms can significantly save the original F-OFDM complexity (up to 100 times) without significant performance loss.
2021
Previous generations of wireless technologies from 0G through 4G used synchronous data transmission for multiple users, which made it difficult to accommodate recent wireless devices and increasing user demands. The Fifth Generation (5G) network standardized by the year 2020 was designed to harmonize the use of asynchronous transmission. This is to accommodate not only new devices and multiple users, but also different type of users. In this regard, so many mitigation schemes were developed to meet the 5G and 5G-A expectations but suffered one limitation or the other, such as Inter Symbol Interference (ISI), Inter Channel Interference (ICI), Peak to Average Power Ratio (PAPR), and more. Each limitation had serious damaging effect on the performance of the 5G network because the techniques were not appropriate. Hence, this paper, presented a novel Feedback Filtered Orthogonal Frequency Division Multiplexing (FF-OFDM) scheme with performance indices of Bit Error Rate (BER) and Signal ...
On the potential of OFDM enhancements as 5G waveforms
The ideal radio waveform for an upcoming 5 th Generation (5G) radio access technology should cope with a set of requirements such as limited complexity, good time/frequency localization and simple extension to multi-antenna technologies. This paper discusses the suitability of Orthogonal Frequency Division Multiplexing (OFDM) and its recently proposed enhancements as 5G waveforms, mainly focusing on their capability to cope with our requirements. Significant focus is given to the novel zero-tail paradigm, which allows boosting the OFDM flexibility while circumventing demerits such as poor spectral containment and sensitivity to hardware impairments.
Under Test Filtered-OFDM And UFMC 5g Waveform Using Cellular Network
Journal of Southwest Jiaotong University
In this study, filtered orthogonal frequency division multiplexing (F-OFDM) and universal filtered multicarrier (UFMC) were proposed for complexity reduction in the 5G waveform. Cyclic prefix orthogonal frequency division multiplexing (CP_OFDM) is well suited for 4G; however, the major problem of the 4G modulation methods is their susceptibility to high peak to average power ratio (PAPR). Another problem of OFDM is the issue of sideband leakage. The existing 4G systems mainly depend on the CP_OFDM waveform, which cannot support the host of applications provided by the 5G platform. 5G-generated traffic is likely to exhibit different features and requirements compared to the existing wireless technology. Consequently, investigations have been devoted to other multiple access schemes. The existing limitations of OFDM can be mitigated by using the UFMC technique. To ensure that the demands and requirements of the upcoming 5G cellular networks are satisfied, this study presents an enable...
Analysis of Candidate Waveforms for 5G Cellular Systems
Towards 5G Wireless Networks - A Physical Layer Perspective, 2016
Choice of a suitable waveform is a key factor in the design of 5G physical layer. New waveform/s must be capable of supporting a greater density of users, higher data throughput and should provide more efficient utilization of available spectrum to support 5G vision of "everything everywhere and always connected" with "perception of infinite capacity". Although orthogonal frequency division multiplexing (OFDM) has been adopted as the transmission waveform in wired and wireless systems for years, it has several limitations that make it unsuitable for use in future 5G air interface. In this chapter, we investigate and analyse alternative waveforms that are promising candidate solutions to address the challenges of diverse applications and scenarios in 5G.
OFDM Pulse Shaping for use in 5G Systems
2015
Currently new waveforms spectrally more efficient than the Orthogonal Frequency Division Multiplexing (OFDM) modulation are being studied by recent research projects for the development of the 5G physical layer. Although OFDM has powerful features such as implementation flexibility and robustness against channel selectivity and intersymbol interference (ISI), its use is not certain in the new emerging communication systems mainly due to its carrier frequency offset sensitivity, very large dynamic amplitude range, and high-power spectral sidelobes around active subcarriers eventually generating out-ofband emissions (OOBE) which in some cases cause intercarrier interference (ICI) among channels. These drawbacks limit its use in heterogeneous and densed 5G networks and in fragmented spectrum and cognitive radio scenarios where flexible use of spectrum is very important. This paper presents the analysis of the time-domain windowing technique applied to OFDM (W-OFDM) to deal with the OFDM OOBE problem. The effect of windowing is analytically derived and constraints are given on the window formats to guarantee the non significant signal-tointerference power ratio (SIR) and BER degradations caused by ISI and ICI. Numerical simulations are elaborated for a scenario based on 5-MHz 3GPP Long-Term Evolution (LTE) and multipath channel.