Filtered Orthogonal Frequency Division Multiplexing Research Articles

Low PAPR Filtered OFDM using Modified Selective Mapping

Wireless Communication has been witnessing generational change in the span of eight to ten years since it came in existence. From generation 1G to 3G and from 4G to 5G the telecommunication world has seen significant improvements along with enhanced performance with every passing year. The objective of research is to comprehensive study of Filtered Orthogonal Frequency Division Multiplexing (F-OFDM) as a promising waveform option for fifth-generation (5G) communications, distinguished by its capacity to suppress out-of-band emission (OOBE) and accommodate asynchronous transmission. Though there are many advantages but the challenge of a high peak-to-average power ratio (PAPR) among new waveform candidates can’t be ignored. To address this problem, the selective mapping technique is used as a key method to alleviate the elevated PAPR trend within multicarrier systems. This research put emphasis on applying selective mapping technique to overcome the high PAPR values in an F-OFDM system with different windowed filters such as kaiser, Nuttles blackman harris and Root raised cousine followed by a proposed Modified Selective mapping technique for further improved performance in terms of PAPR for the Filtered OFDM for different window functions in comparison with the conventional OFDM system, SLM F-OFDM system. Furthermore, PAPR performance is evaluated for all the three-system using the different window techniques analyzed for both systems, both with and without the SLM technique and Modified SLM technique to mitigate the PAPR disadvantage of the Filtered OFDM system. Simulation results underscore that F-OFDM enhanced by SLM and MSLM outperforms OFDM across PAPR.

Filtered Ofdm System Model for Papr Reduction in the Growth Of 5g

A proposed waveform for fifth generation (5G) communications is the filtered orthogonal frequency division multiplexing (F-OFDM) system. Filtering-based waveform frameworks distinguish themselves by suppressing out-of-band emission and asynchronous transmission. Meanwhile, the high Peak-To-Average Power Ratio (PAPR) remains a barrier to new waveform possibilities. Partials transmit sequence (PTS) is a successful strategy for reducing high PAPR in multicarrier networks. This work presents a multicarrier in OFDM and UFMC based on the Filter Bank Multicarrier (FBMC) waveform for communication systems. Furthermore, FBMC waveforms have limited orthogonality between subcarriers, which can mitigate Doppler and multipath effects. This FBMC approach uses the cosine law to filter the traffic signal, and the Welch algorithm is offered for segmentation, which lowers noise in estimated power spectra. As a result, a hybrid Selective Mapping (SLM) with Cuckoo Search and Ant Lion Optimization (CS-ALO) algorithms is suggested using the FBMC framework to reduce PAPR in the OFDM system. The proposed work is implemented, and detailed experimental research is carried out to show the increased performance in 5G networks. Based on a fair comparison, the F-OFDM scheme outperforms previous approaches in terms of BER and multicarrier system capacity. Simulation results show that the proposed waveform design and processing method outperform standard OFDM and F-OFDM methods in PAPR reduction and communication integrated systems.

Enhancing spectral efficiency with low complexity filtered‐orthogonal frequency division multiplexing in visible light communication system

AbstractThe filtered‐orthogonal frequency division multiplexing (F‐OFDM) scheme has gained attention as a promising solution in the field of visible light communication (VLC) systems. One crucial aspect in VLC is the conversion of the complex F‐OFDM signal into a real signal that corresponds with direct detection and intensity modulation. Traditionally, achieving a real F‐OFDM signal has involved imposing Hermitian symmetry (HS) on the samples of the Inverse Fast Fourier transform (IFFT), which requires 2N‐point IFFT and obtains an N‐point FFT, thus adding complexity. In this study, a novel approach is presented and implemented, aiming to enhance spectral efficiency and reduce system complexity by generating a real F‐OFDM signal without relying on HS. This approach is then compared with HS‐free (HSF)‐OFDM, direct current biased optical OFDM, and asymmetrically clipped optical OFDM. The suggested method offers a remarkable improvement of ~50% in the required IFFT/FFT volume. Consequently, this method reduces hardware complexity and power usage compared with the traditional F‐OFDM method. Moreover, regarding error rates, the proposed method demonstrates better spectral efficiency than HSF‐OFDM.

Improved autocorrelation method for time synchronization in filtered orthogonal frequency division multiplexing

Time synchronization is essential in multicarrier systems such as filtered orthogonal frequency division multiplexing (F-OFDM) because it determines the whole system’s performance. Differ with OFDM, where subcarrier allocation is not flexible. In F-OFDM, the subcarrier allocation is more flexible, and the whole subcarrier in one symbol can be grouped into several subbands. The use of subcarriers that are limited to only one subband can reduce the performance of time synchronization based on autocorrelation (AC) methods. In this study, we first compare the performance of the AC-based time synchronization algorithms used in F-OFDM when training symbols are limited to one subband. Secondly, we made improvements to the AC-based time synchronization with the averaging technique of its timing metric, thus increasing the accuracy of time estimates in the F-OFDM system. The averaging technique of the timing metric improved the performance of the AC method in cases where the training symbol is limited to one subband, as shown in the simulation results.

Massive Connectivity and Low-Latency for Next-Generation Internet of Things: A Filtered OFDM-based Deep Learning Approach

Abstract The Internet of Things (IoT) is one of the numerous services offered by sixth-generation (6G) mobile communications. It is necessary to meet heterogeneous criteria for large connectivity and low latency to serve the various kinds of IoT applications. In order to concurrently provide enormous connectivity and meet the low-latency conditions in the uplink IoT network, we proposed filtered orthogonal frequency division multiplexing (FOFDM) based on a service group adopting the deep learning (DL) technique. The proposed FOFDM-DL platform focuses on two key areas: first, it works for the concurrence of different time-frequency granularity appropriate for distinct service-based grouping, and secondly, it facilitates low latency and massive connectivity to deliver dependable communications. The suggested FOFDM-DL architecture may accommodate the needs of massive machine-type communication referred as mMTC and ultra-reliable and low-latency communications known as uRLLC concurrently for the next-generation communication systems. However, the uRLLC and mMTC requirements can only be supported separately by the new radio (NR)-5G, beyond 5G (or 6G). In comparison to the traditional scheme, simulation results demonstrate that the suggested FOFDM-DL platform works surprisingly well in the next-generation IoT network.

An analysis of 5G-MIMO communication system based SS for centralized cooperative and non-cooperative users

The purpose of 5G-MIMO communication systems is to boost the intensity of the received signal, and facilitate the application of the users’ apparatus. However, in band-grabbing systems such as these, the accessibility of a spectrum is hindered by gridlocks. Also, to be considered is the spectrum’s waveform, which is the type that contends with 5G networks specifically. This undertaking involves the development of a 5G-MIMO communication system based SS, in which the spectrum is enhanced, by way of a spectrum sensing (SS) algorithm. By replicating the energy detection procedure, this recommended SS algorithm engages the cosine law to filter the traffic signal, and subsequently portions it using the Welch algorithm. The Hann algorithm is then utilized, to window the traffic signal, to damp the high power delivered to the MIMO. The key role, of the SS algorithm, is to sense a spectrum for 5G-MIMO communication system, with the capacity to damp the MIMO effect for a variety of waveforms. The SS algorithm expressions are applicable for both non-cooperative and centralized cooperative users. For each expression, an examination was performed for waveforms used by 5G-MIMO communication systems. This included filtered-orthogonal frequency division multiplexing (F-OFDM), universal filtered multi-carrier (UFMC), and filter bank multi-carrier (FBMC) waveforms. The operating parameters, including SNR, the signal span and power, the antenna count, as well as the types of modulation for both non-cooperative and centralized cooperative users, were scrutinized. The simulation results revealed a notable achievement for the parameters lower than zero dB of SNR, greater than 95% global detection probability, less than 1% global system error probability, and less than 1% global false alarm probability. An evaluation of the recommended system’s parameters discloses its superiority, in comparison to other previously developed systems.

An adaptive channel estimation scheme based on redundancy minimization for filtered OFDM networks

Filtered orthogonal frequency division multiplexing (F-OFDM), a technology which is being considered as a promising platform for beyond 4G era is expected to help deliver the new features at millimeter wave in the new 5 th generation of cellular communication. Some of its key features notably better spectral utilization, enhanced throughput and immunity to interference can be enabling for the new cellular standards. These features of filtered OFDM comes with strict requirements of filter design, guard tone managements, and efficient channel state information harness. This paper is intended to propose an intuitive channel estimation scheme which will allow efficient acquisition of channel state information (CSI) through exploiting the redundant steps of the conventional pilot training-based algorithms and by also using an adaptive weight to expedite the minimization of the error between the estimated values and the actual values. Various simulations will follow to demonstrate the superiority of the scheme over traditional pilot-based algorithms and thus prove its utility in the current 5G cellular era.

The impact of M-ary rates on various quadrature amplitude modulation detection

The 5G system-based cognitive radio network is promised to meet the requirements of huge data applications with spectrum. However, the M-ary effect on the detection has not been thoroughly investigated. In this paper, an M-ary of quadrature amplitude modulation detection system is studied. Many rates are used in this study 4, 16, 64, and 256 constellation points. The detection system is applied to cooperative spectrum sensing to enhance the performance of detection for various rates of M-ary with low signal-to-noise ratio (SNR). Further, three kinds of signals based 5G system are sensed: filtered-orthogonal frequency division multiplexing (F-OFDM), filter bank multi-carrier (FBMC), and universal filtered multi-carrier (UFMC). The best detection performance is obtained when the M-ary=4 and number of SUs=50 user, whereas the worst detection performance is obtained when the M-ary=256 and number of SUs=10 user, as revealed in the simulation results. In addition, the detection performance for the F-OFDM signal is better than that of UFMC and FBMC signals for SNR <0 dB.

An analysis of low complexity of 5G-MIMO communication system based CR using hybrid filter detection

The exponential growth in wireless communication has resulted in a high demand for novel wireless services within the frequency bands that can deal with the challenge pertaining to the current spectrum shortage. Thus, a 5G-MIMO based CR communication system has been developed to enhance the spectrum by employing a spectrum sensing (SS) algorithm. This recommended SS algorithm, based on the hybrid filter detection (HFD) method, employs the Cosine law for filtering the traffic signal, and then enables segmentation by applying the Welch algorithm. Then, the Hann algorithm is employed to window the traffic signal, and facilitates damping the MIMO impact for different waveforms. This also includes universal filtered multi-carrier (UFMC), filtered-orthogonal frequency division multiplexing (F-OFDM), filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and Generalized Frequency Division Multiplexing (GFDM) waveforms. Also, evaluation of the operating parameters such as SNR, the antenna count, the signal span, and power as well as computational complexity was done. Based on the simulation results, a notable achievement was seen for the parameters that were below 0 dB of SNR, <0.09 % global system error probability, >96 % global detection probability, <0.06 % global false alarm probability, and possessing simple complexity. The recommended system’s parameters were assessed, which demonstrated its superiority versus other previously developed systems. This algorithm was found to identify all types of 5G signals and not just one type of 5G.

Multicarrier Modulation Schemes for 5G Wireless Access

The 5G wireless access technology will supersede its predecessor, 4G, in the current decade, at first coexisting with it and later as a standalone technology. This work examines and compares the performance of the following orthogonal multicarrier schemes: Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM), Windowed Orthogonal Frequency Division Multiplexing (W-OFDM), Filtered Orthogonal Frequency Division Multiplexing (F-OFDM), Universal Filtered Multi-Carrier (UFMC), and Filter Bank Multi-Carrier (FBMC). The system architecture of each scheme is investigated while considering the performance in fading channel models. The simulation was performed using a standard set of parameters, and the performance was appraised based on Power Spectral Density (PSD), Peak to Average Power Ratio (PAPR), Complementary Cumulative Distribution Function (CCDF) of PAPR, Bit Error Rate (BER), and Signal to Noise Ratio (SNR). In addition, a comprehensive analysis is presented concerning filter or window implementation, filtering method, orthogonality, roll-off rate, spectral leakage, spectral efficiency, computational complexity, and runtime complexity. Based on the results, each scheme has its advantages and disadvantages compared with the other methods. FBMC, F-OFDM, and W-OFDM are preferred for better spectrum utilization, transmission accuracy, and power efficiency, respectively. UFMC offers a fine balance between these multicarrier schemes. Therefore, the modulation scheme for the future physical layer will strongly depend on the requirements.

Performance analysis of modulation techniques in 5G communication system

In the 5 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> generation mobile communication (5G) system, better bitrate, better power consumption, and better Bit Error Rate are needed. To meet all these requirements in 5G, the waveform is important. Although the Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme has been commonly used in 4G, it is difficult to meet the requirements of 5G. A lot of candidate waveforms are discussed in the 5G system included Filter Bank Multicarrier (FBMC), Universal Filtered Multicarrier (UFMC), Filtered OFDM (F-OFDM), and Generalized Frequency Division Multiplexing (GFDM), etc. However, since GFDM is no longer widely used, in this paper, FBMC, UFMC, and F-OFDM modulation schemes are discussed and compared with OFDM. Power Spectral Density (PSD), Bit Error Rate (BER), Transmitted Signal Power, Peak Average Power Ratio (PAPR) and Bit Rate parameters of the modulation schemes are studied and compared with OFDM. FBMC demonstrates to be the most promising modulation scheme for 5G systems.

A CR-5G network based on multi-user for various waveforms detection

The 5G network is promised to provide all the requirements surfacing from the speedily rising number of mobile phone users rather than huge amount of data transmission. Many 5G waveforms can be used by 5G network such as Filtered-Orthogonal Frequency Division Multiplexing (F-OFDM), Universal Filtered Multi-Carrier (UFMC), or Filter Bank Multi-Carrier (FBMC) waveform. To effectively capitalize on the spectrum resources, Internet of Thing (IoT), and multimedia transmission, the Cooperative Spectrum Sensing (CSS) system is being extensively utilized by Cognitive Radio (CR). It is able to meet the requisite communication services, however, the conventional CSS systems have been designed to detect only single kind of 5G waveform and poor detection performance for low signal-to-noise ratio (SNR). In this paper, a hybrid filter based CSS system is proposed for detection of various 5G waveforms by multi-user. The proposed filter includes three cascaded stages: cosine filtering, Welch segmentation, and Hamming windowing. The proposed detection system is applied on different data such as various of waveforms and SNRs. The simulation results exhibit a significant detection performance for the parameters of less than zero dB of SNR, greater than 95% global detection probability, less than 1% global system error probability, and less than 1% global false alarm probability. In addition, the detection performance reveals that the proposed system is outperformed related works as shown in the comparison in terms of the previous parameters.

Filtered OFDM PAPR performance for 5G communications is improved utilizing PTS

A waveform candidate for fifth-generation (5G) communications has been recommended: the filtered orthogonal frequency division multiplexing (F-OFDM) system. Filtering-based waveform frameworks are distinguished by the suppression of out-of-band emission (OOBE) and asynchronous transmission. As a result, the new waveform candidates are still struggling with the PAPR issue. In multicarrier systems, partial transmit sequence (PTS) is an efficient way to combat the rising tendency of PAPR. The high PAPR value of an F-OFDM system is reduced using the PTS technique in this study. The OFDM system is then put up against this one. Other relevant metrics, such as frequency localization, bit error rate (BER), and computational complexity, are evaluated and analysed in both systems with and without PTS. According to simulation studies, F-OFDM based on PTS provides better PAPR, BER, and OOBE than OFDM. F-BER OFDM's is unaffected by the PTS technique's implementation.

Implementing Enhanced MIMO with F-OFDM to Increase System Efficiency for Future 5G Cellular Networks

The upcoming fifth generation of cellular communication system is most likely to be deployed by the year 2020. The new generation of mobile network is expected to have high data rates, low latency and support a huge number of devices. Aside from this, machine type communication (MTC) and internet of things (IoT) are expected to be handled by 5G system in a better and efficient way. For this reason, a number of waveform candidates have been proposed. Filtered orthogonal frequency division multiplexing (F-OFDM) is one of the proposed candidates for 5G systems, which highly resembles to its predecessor that is orthogonal frequency division multiplexing (OFDM). The crucial difference between the two multicarrier waveforms is the use of a well-designed filter. F-OFDM in comparison with OFDM thus provides reduced out of band emission, which enables it to utilize the allocated spectrum efficiently. This research paper provides a brief review of F-OFDM performance with multiple input multiple output (MIMO) implementation. Using MATLAB, the MIMO system with F-OFDM has been tested for different configurations such as SIMO (receive diversity) and MISO (transmit diversity) with different digital modulation schemes including QPSK, 16-QAM, 64-QAM and 256-QAM. The bit error rate (BER) vs the signal to noise ratio (SNR) plots judge the performance of the system.

Investigation of pattern division multiple access technique in wireless communication networks

Recently, &lt;span&gt;pattern division multiple access (PDMA) is a non-orthogonal multiple access system that is now being developed in next-generation telecoms to address the requirement for mass connectivity. The core premise of non-orthogonal multiple access is to simultaneously serve multiple users with varying power levels across the same spectrum resources such as time, frequency, code, as well as space with minimal inter-user interference. A simulation analysis of significant technology enhancements focusing on PDMA aims to describe the benefits of the two plans now being examined by the third-generation partnership project for 5G technologies, namely filtered orthogonal frequency division multiplexing (F-OFDM) and windowed orthogonal frequency division multiplexing (W-OFDM), and to compare them to alternative modulation processes such as 16, 32, and 128 modulations. The research results explained the PDMA is less bit error rate used in multiple access technologies compare with W-OFDM and F-OFDM.&lt;/span&gt;

Filtered-orthogonal wavelet division multiplexing (F-OWDM) technique for 5G and beyond communication systems.

Filtered-orthogonal frequency division multiplexing (F-OFDM) is one of the most protruding multicarrier modulation (MCM) techniques for fifth-generation and beyond wireless communication. However, it possesses a high peak-to-average power ratio (PAPR), which results in its poor performance. Thus, a novel wavelet based MCM technique, namely filtered orthogonal wavelet division multiplexing (F-OWDM), is proposed as an efficient alternative to conventional F-OFDM (C-F-OFDM) to reduce the PAPR. In this model, the traditional Fourier transforms (FT) as used in C-F-OFDM was replaced with Wavelet Transforms. The proposed F-OWDM system does not require a cyclic prefix because of the overlapping sub-carriers in the time and frequency domains. Thus, the F-OWDM system exhibits higher bandwidth efficiency. In this paper, the performance of the F-OWDM system with various wavelets from different wavelet families under an additive white Gaussian noise and flat fading channel is investigated. The PAPR and bit error rate (BER) of the F-OWDM system using Haar, discrete Meyer, bi-orthogonal, symlet, and Daubechies wavelets are analyzed. A comparative study between F-OWDM and C-F-OFDM is also presented. From the results, it is able to prove that F-OWDM has the advantage of lower PAPR and lower bit error rate than the C-F-OFDM system.

Architecture Optimization for Filtered Multicarrier Waveforms in 5G

Wireless communication network is the backbone of each and every organization of today modern globe. The rapid emergence of smart devices, smart homes, internet of things and clean energy become key sources in today society. In result the data traffic, emerging of new service and application are increased every year. Hence, there is a growing demand for 5G technology in all above mentioned fields. Therefore, better waveform types for 5G technology is needed, which has ability of high spectral efficiency, lower latency and less complexity. It is predicted that the data traffic will arise 1000 × in near future. In this work filtered orthogonal frequency division multiplexing (F-OFDM) and universal filtered orthogonal frequency division multiplexing (UF-OFDM) techniques are discussed to degrade key issues such as computational complexity, peak average power ratio (PAPR), lower spectral efficiency, and higher latency. The suggested work decreases the drawbacks faced by previous work like limited capacity and complexity. We also analyze algorithms and simplification for F-OFDM and UF-OFDM waveforms from an implementation perspective towards low complexity and efficient transceiver design. Moreover, F-OFDM and UF-OFDM are studied based on multicarrier modulation and enabled to reduce to out-of-band power leakage (OOBPL) of OFDM.

5G F-OFDM Waveform Based Software-Defined 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.

Theoretical Analysis and Performance Comparison of Multi-carrier Waveforms for 5G Wireless Applications

Fifth generation (5G) wireless technology is a new wireless communication system that must meet different complementary needs: the high data rate for mobile services, low energy consumption and long-range for connected objects, low latency to ensure real-time communication for critical applications and, high spectral efficiency to improve the overall system capacity. The waveforms and associated signal processing present a real challenge in the implementation of each generation of wireless communication networks. Different research works have discussed this topic; but, these works are limited to the Filter-Bank Multi-Carrier (FBMC), Universal Filtered Multi-Carrier (UFMC), and Filtered Orthogonal Frequency-Division Multiplexing (F-OFDM) waveforms. In this work, we review the technical basics of the physical layer for the LTE system which uses, OFDM modulation for the downlink and the single carrier frequency division multiple access (SC-FDMA) technique for the uplink. Besides, this paper presents the diverse waveforms candidate for 5G systems, including, FBMC, UFMC, and F-OFDM, and compares these techniques with Constant Envelope-OFDM (CE-OFDM), which is an advantageous form regarding power consumption, especially for battery-powered devices. Simulations are carried out to compare the performance of the OFDM, CE-OFDM, F-OFDM, UFMC, and FBMC in terms of power spectral density (PSD) and Bit Error Rate (BER). It has been demonstrated that (CE-OFDM) constitutes a more efficient solution in terms of energy consumption than the other technics. By comparison with the other technics, the CE-OFDM scheme performances, in terms of BER and PSD, are controllable by the values of its parameters (M, h, and J). This advantage gives designers of the system to consider the mutual choice between spectral efficiency and the BER. Moreover, the (F-OFDM), (UFMC), and (FBMC) schemes could constitute a more efficient solution in terms of power spectral density. It can be concluded from this paper that CE-OFDM wave form gives the best performance in terms of power consumption by reducing the Peak to Average Power Ratio (PAPR) associated with the OFDM system and FBMC is an efficiency technique to reduce the inter-carrier interference (ICI).

Performance Analysis of Filtered OFDM Based Downlink and Uplink NOMA System over Nakagami-m Fading Channel

Efficient consumption of available resources and fulfillment of increasing demands are the two main challenges which are addressed by exploring advanced multiple access schemes along with efficient modulation techniques. To this end, non-orthogonal multiple access (NOMA) is discussed as a promising scheme for future 5G traffic. NOMA enables the users to share same resource block, permitting certain level of interference. In this paper, we propose filtered OFDM (F-OFDM) as a transmission waveform for NOMA systems, as it offers all the advantages of OFDM with the additional provision of sub-band filtering to satisfy the diverse services of the users. We examine F-OFDM in both downlink and uplink NOMA systems. Error-related performances of both downlink and uplink F-OFDM NOMA systems are analyzed and compared with conventional OFDM NOMA system over Nakagami-m fading channel. The results show that the error performance of F-OFDM NOMA is better than that of OFDM NOMA. An improvement of about 2 dB and 1 dB in bit error rate is achieved in downlink and uplink F-OFDM NOMA, respectively. Monte Carlo simulations are conducted for different values of fading parameter m, supporting the obtained analytical results