A Novel PAPR Reduction in Filter Bank Multi-Carrier (FBMC) with Offset Quadrature Amplitude Modulation (OQAM) Based VLC Systems

The peak to average power ratio (PAPR) is one of the major problem with multicarrier-based systems. Due to its improved spectral efficiency and decreased PAPR, Filter Bank Multicarrier (FBMC) has recently become an effective alternative to the orthogonal multiplexing division (OFDM). For filter bank multicarrier communication/offset quadrature amplitude modulation-Visible light communication (FBMC/OQAM-VLC) systems is proposed a PAPR reduction technique. The suggested approach overlaps the proposed FBMC/OQAM-based VLC data signal with the existing signals. Non-redundant signals and data signals do not overlap in the frequency domain because data signals are scattered on odd subcarriers whereas built signals use even subcarriers. To reduce the effects of large-amplitude signal reduction, the suggested technique converts negative signals into positive signals rather than clipping them off as in conventional FBMC-based VLC systems. The PAPR reduction and bit error rate (BER) are realized using a scaling factor in the transformed signals. Complementary cumulative distribution function(CCDF) and BER are used to calculate the performance of the proposed approach. The presented study found that FBMC/OQAM-VLC systems to achieve a good trade-off between PAPR reduction and BER

Integration of hybrid networks, AI, Ultra Massive-MIMO, THz frequency, and FBMC modulation toward 6g requirements : A Review

The fifth-generation (5G) wireless communications have been deployed in many countries with the following features: wireless networks at 20 Gbps as peak data rate, a latency of 1-ms, reliability of 99.999%, maximum mobility of 500 km/h, a bandwidth of 1-GHz, and a capacity of 106 up to Mbps/m2. Nonetheless, the rapid growth of applications, such as extended/virtual reality (XR/VR), online gaming, telemedicine, cloud computing, smart cities, the Internet of Everything (IoE), and others, demand lower latency, higher data rates, ubiquitous coverage, and better reliability. These higher requirements are the main problems that have challenged 5G while concurrently encouraging researchers and practitioners to introduce viable solutions. In this review paper, the sixth-generation (6G) technology could solve the 5G limitations, achieve higher requirements, and support future applications. The integration of multiple access techniques, terahertz (THz), visible light communications (VLC), ultra-massive multiple-input multiple-output ( μm -MIMO), hybrid networks, cell-free massive MIMO, and artificial intelligence (AI)/machine learning (ML) have been proposed for 6G. The main contributions of this paper are a comprehensive review of the 6G vision, KPIs (key performance indicators), and advanced potential technologies proposed with operation principles. Besides, this paper reviewed multiple access and modulation techniques, concentrating on Filter-Bank Multicarrier (FBMC) as a potential technology for 6G. This paper ends by discussing potential applications with challenges and lessons identified from prior studies to pave the path for future research

A Survey of Blind Modulation Classification Techniques for OFDM Signals

Blind modulation classification (MC) is an integral part of designing an adaptive or intelligent transceiver for future wireless communications. Blind MC has several applications in the adaptive and automated systems of sixth generation (6G) communications to improve spectral efficiency and power efficiency, and reduce latency. It will become a integral part of intelligent software-defined radios (SDR) for future communication. In this paper, we provide various MC techniques for orthogonal frequency division multiplexing (OFDM) signals in a systematic way. We focus on the most widely used statistical and machine learning (ML) models and emphasize their advantages and limitations. The statistical-based blind MC includes likelihood-based (LB), maximum a posteriori (MAP) and feature-based methods (FB). The ML-based automated MC includes k-nearest neighbors (KNN), support vector machine (SVM), decision trees (DTs), convolutional neural networks (CNNs), recurrent neural networks (RNNs), and long short-term memory (LSTM) based MC methods. This survey will help the reader to understand the main characteristics of each technique, their advantages and disadvantages. We have also simulated some primary methods, i.e., statistical- and ML-based algorithms, under various constraints, which allows a fair comparison among different methodologies. The overall system performance in terms bit error rate (BER) in the presence of MC is also provided. We also provide a survey of some practical experiment works carried out through National Instrument hardware over an indoor propagation environment. In the end, open problems and possible directions for blind MC research are briefly discussed

An efficient reconfigurable peak cancellation model for peak to average power ratio reduction in orthogonal frequency division multiplexing communication system

The peak to average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) communication system will be reduced using reconfigurable peak cancellation (RPC). RPC will also aid in improves the error vector magnitude (EVM) and reduces adjacent channel leakage ratio (ACLR) in OFDM communication system. The proposed RPC design methodology and practical implementation using field programmable gate array (FPGA) are discussed. The proposed RPC has been demonstrated using VIRTEX-7 XC7Z100 dual-core FPGA device with less hardware difficulty and minimum utilization of FPGA resources. The proposed RPC improves the efficiency of OFDM communication process by reducing complementary cumulative distribution function (CCDF) with respect to instantaneous power in dB. A comparison analysis was done between the existing selective mapping (SLM) method with proposed RPS method with respect FPGA resource utilization. The proposed RPC is implemented using VIRTEX-7 XC7Z100 dual-core FPGA device. Its effectively utilizing sub-carriers, fast Fourier transform (FFT) filter, bandwidth, and sampling frequency. Due to parallel switching operation, it reduces the PAPR, ACLR and improves EVM in OFDM signal with less hardware complexity

Results and achievements of the ALLIANCE Project: New network solutions for 5G and beyond

Leaving the current 4th generation of mobile communications behind, 5G will represent a disruptive paradigm shift integrating 5G Radio Access Networks (RANs), ultra-high-capacity access/metro/core optical networks, and intra-datacentre (DC) network and computational resources into a single converged 5G network infrastructure. The present paper overviews the main achievements obtained in the ALLIANCE project. This project ambitiously aims at architecting a converged 5G-enabled network infrastructure satisfying those needs to effectively realise the envisioned upcoming Digital Society. In particular, we present two networking solutions for 5G and beyond 5G (B5G), such as Software Defined Networking/Network Function Virtualisation (SDN/NFV) on top of an ultra-high-capacity spatially and spectrally flexible all-optical network infrastructure, and the clean-slate Recursive Inter-Network Architecture (RINA) over packet networks, including access, metro, core and DC segments. The common umbrella of all these solutions is the Knowledge-Defined Networking (KDN)-based orchestration layer which, by implementing Artificial Intelligence (AI) techniques, enables an optimal end-to-end service provisioning. Finally, the cross-layer manager of the ALLIANCE architecture includes two novel elements, namely the monitoring element providing network and user data in real time to the KDN, and the blockchain-based trust element in charge of exchanging reliable and confident information with external domains.This work has been partially funded by the Spanish Ministry of Economy and Competitiveness under contract FEDER TEC2017-90034-C2 (ALLIANCE project) and by the Generalitat de Catalunya under contract 2017SGR-1037 and 2017SGR-605.Peer ReviewedPostprint (published version

A hybrid-structure offset-QAM filter-bank multi-carrier MIMO system

Offset quadrature amplitude modulation (OQAM) filter-bank multi-carrier (FBMC), has great potential for boosting the spectral efficiency (SE) and energy efficiency (EE) of future communication systems. This is due to its superior spectral localization, CP-less transmission and relaxed synchronization requirements. Our research focuses on three main OQAM/FBMC research problems: the computational complexity reduction taking equalization into consideration, its integration with multiple-input multiple-output (MIMO) and its high peak-to-average power ratio (PAPR). OQAM/FBMC systems are mainly implemented either using frequency spreading (FS) or polyphase network (PPN) techniques. The PPN technique is generally less complex, but when using frequency domain equalization (FDE) to equalize multipath channel effects at the receiver, there is a computational complexity overhead when using PPN. A novel hybrid-structure OQAM/FBMC MIMO space-frequency block coding (SFBC) system is proposed, to achieve the lowest possible overall complexity in conjunction with FDE at the receiver in frequency selective Rayleigh fading channel. The Alamouti SFBC block coding is performed on the complex-orthogonal signal before OQAM processing, which resolves the problems of intrinsic interference when integrating OQAM/FBMC with MIMO. In better multipath channel conditions with a line-of-sight (LOS) path, a zero-forcing (ZF) time domain equalization (TDE) is exploited to further reduce the computational complexity with comparable performance bit-error-rate (BER). On the other hand, to tackle the high PAPR problem of the OQAM/FBMC system in the uplink, a novel single carrier (SC)-OQAM/FBMC MIMO system is proposed. The system uses DFT-spreading applied to the OQAM modulated signal, along with interleaved subcarrier mapping to significantly reduce the PAPR and enhance the BER performance over Rayleigh fading channels, with relatively low additional computational complexity compared to the original complexity of the FBMC system and compared to other FBMC PAPR reduction techniques.The proposed hybrid-structure system has shown significant BER performance in frequency-selective Rayleigh fading channels compared to OFDM, with significantly lower OOB emissions in addition to the enhanced SE due to the absence of CP. In mild multipath fading channels with a LOS component, the PPN OQAM/FBMC MIMO using TDE has a comparable BER performance with significantly less computational complexity. As for the uplink, the SC-OQAM/FBMC MIMO system significantly reduces the PAPR and enhances the BER performance, with relatively low additional computational complexity

Power Converters in Power Electronics

In recent years, power converters have played an important role in power electronics technology for different applications, such as renewable energy systems, electric vehicles, pulsed power generation, and biomedical sciences. Power converters, in the realm of power electronics, are becoming essential for generating electrical power energy in various ways. This Special Issue focuses on the development of novel power converter topologies in power electronics. The topics of interest include, but are not limited to: Z-source converters; multilevel power converter topologies; switched-capacitor-based power converters; power converters for battery management systems; power converters in wireless power transfer techniques; the reliability of power conversion systems; and modulation techniques for advanced power converters