Filter Bank Multicarrier Research Articles

Visible light communication optical FBMC-OQAM PAPR reduction using FHT-PTR algorithm for beyond 5G system

Abstract This paper addresses the reduction of peak-to-average power ratio (PAPR) in optical filter bank multicarrier (FBMC) with offset quadrature amplitude modulation (OQAM) using a fast Hadamard transform (FHT) centered partial transmit sequence (PTS) algorithm. High PAPR in FBMC-OQAM systems can cause non-linear distortions in optical transmitters, such as LEDs, leading to signal degradation. The proposed FHT-PTS algorithm effectively mitigates this issue by dividing the data symbols into disjoint subsets, applying phase rotations, and performing inverse FHT to generate multiple candidate sequences. The sequence with the lowest PAPR is selected for transmission. This technique ensures significant PAPR reduction while maintaining acceptable bit error rate (BER) performance. Simulation results demonstrate that the FHT-PTS algorithm achieves substantial PAPR reduction gain of 3 dB–6 dB compared to conventional PTS and other existing methods. The power spectrum density (PSD) analysis shows that the spectral efficiency of the FBMC-OQAM system is preserved, with minimal out-of-band emissions. The FHT operations significantly reduce the complexity compared to traditional Fourier transform-based methods, making the algorithm more feasible for real-time applications.

Performance study of the compensations dispersion systems for an optical filter bank multicarrier transceivers technique

Performance study of the compensations dispersion systems for an optical filter bank multicarrier transceivers technique

CD-aware non-orthogonal DFT-precoding for C-band IM/DD multicarrier signals over a 50-km dispersion-uncompensated link.

In this paper, a chromatic-dispersion-aware non-orthogonal discrete Fourier transform precoding (CDA-NODFTP) scheme is proposed for CD-constrained intensity-modulation and direct detection (IM/DD) multicarrier-signal transmission systems. The performance of the proposed CDA-NODFTP scheme is experimentally evaluated and compared with conventional DFTP and NODFTP schemes over a 50-km C-band dispersion-uncompensated link, utilizing 90-Gb/s orthogonal frequency division multiplexing (OFDM) and filter bank multicarrier (FBMC) signals. Experimental results show that the proposed CDA-NODFTP with adaptive spectral compression outperforms conventional DFTP, NODFTP, and the non-precoding schemes in terms of bit error rate (BER) performance. Moreover, based on CD response only, the CDA-NODFTP-FBMC exhibits superior performance compared to both CDA-NODFTP-OFDM and adaptive bit and power loading (ABPL) FBMC, achieving receiver sensitivity improvements of over 2 dB at a BER of 3.8 × 10-3.

Spectral efficiency analysis on massive MIMO filter bank

ABSTRACT This article covers the potential of Filter Bank Multicarrier (FBMC) modulation as an alternative to be used in the future 5 G wireless networks in which Massive Multiple-Input Multiple-Output (MIMO) is implemented. The ‘energy efficient Massive Multiple Input Multiple Output (M-MIMO) Filter bank Multi-carrier Modulation (FBMC)’ is necessary and beneficial for the upcoming wireless communiqué system. This is because there is an ever-increasing demand for higher data rates with higher Spectral Efficiency (SE). This paper compares orthogonal frequency division multiplexing (OFDM) with FBMC. This helps to evaluate the Spectral Efficiency (SE) of a Massive MIMO system that performs transmission under a unicellular environment. The variation in Massive MIMO allows equilibrium of the channel because FBMC has extra benefits due to the confinement of the subcarrier in an assigned range. However, the high Peak to Average Power Ratio (PAPR) in an M-MIMO-FBMC system is recognised as a serious problem that causes nonlinear signal deformation and restricts the effectiveness of the Power Amplifier (PA). In this work, to increase the SE in the system, the antenna count is optimised, such that the SNR or SNDR is maximum. For this, the antenna counts are optimised via Self Improved SSO with a Chaotic Map (SISSO-CM).

Automatic classification of multi-carrier modulation signal using STFT spectrogram and deep CNN

In the realm of communication systems, categorizing Multi-Carrier Modulation (MCM) signals without cooperative communication poses a significant technical challenge. In this paper, we introduce a novel approach for accurately categorizing five distinct MCM signals, including Orthogonal Frequency Division Multiplexing (OFDM), Filter Bank Multicarrier (FBMC), Filtered Orthogonal Frequency Division Multiplexing (FOFDM), Windowed Orthogonal Frequency Division Multiplexing (WOLA), and Universal Filtered Multicarrier (UFMC). Each signal is considered with two types of subcarrier waveforms, Quadrature Amplitude Modulation 16 (QAM16) and Quadrature Amplitude Modulation 64 (QAM64), resulting in a total of 10 unique MCM signals for classification. Our proposed methodology leverages Short-Time Fourier Transform (STFT) spectrograms for feature extraction at the frontend, while at the backend, we employ three variants of Convolutional Neural Network (CNN) models; CNN, CNN with Dropout (CNN_d), CNN with both Dropout and L1 Regularization (CNN_dL1) and one deep CNN model; Xception, individually. We aim to provide an efficient and reliable means of categorizing MCM signals, with practical applications in signal processing and communication systems. Extensive simulations demonstrate the effectiveness of our approach, achieving remarkable accuracies. Notably, the Xception model exhibits the highest accuracy among the four models considered. Specifically, we attain an accuracy of 98% at 10 dB SNR using the Xception model. These results underscore the efficacy of our proposed methodology and highlight the potential for its deployment in real-world scenarios.

Effect of Line-of-sight Channels on DC-biased Optical Filter Bank Multicarrier Visible Light Communication with Multiple LED Arrays

This paper investigates the impact of propagation delay and channel loss due to the use of multiple LED arrays in visible light communication (VLC) systems based on filter bank multicarrier (FBMC) modulation. FBMC offers greater spectral efficiency, and asynchronous transmission and is a promising alternative scheme to orthogonal frequency division modulation (OFDM). The proposed FBMC model is based on 4-quadrature amplitude modulation (QAM) and 16-QAM formats and uses 100 symbols and 600 input bits per symbol. In this paper, the VLC-FBMC system is designed based on the line-of-sight (LOS) model under the additive white Gaussian noise (AWGN) channel. Comparison analyses between different bit rates in terms of bit error rate (BER), best sampling point, and signal-to-noise ratio (SNR) requirement have been carried out to show the delay and loss effect on communication quality and system performance. The results demonstrate that the proposed FBMC model achieves a bit rate of up to 29.296 Mbit/s with a low BER of 10-3 and less SNR penalty in high QAM formats, demonstrating its potential as a viable alternative to OFDM for future VLC systems.

The application of artificial intelligence in Unmanned Underwater Vehicle communication systems

Artificial Intelligence (AI) has the potential to significantly enhance decision-making techniques in Unmanned Underwater Vehicle (UUV) communication systems by utilizing real-time sensor feedback and environmental data. To address the challenges posed by high data volume and error rates, we propose an advanced methodology known as the Variational Deep Network (VDN). This method integrates Variational Modal Decomposition (VMD) algorithms with the Deep Convolutional Neural Network (DCNN) to create a realizable AI decision-making system. In conjunction with the DCNN and VMD algorithms, our research focuses on accurately identifying received signals under data constraints. Considering the spectral efficiency and robustness, the Filter-Bank Multicarrier (FBMC) technology have been employed in this paper. Our results demonstrate that the VDN significantly reduces the volume of data needed for neural network training and effectively recognizes FBMC signals. These insights confirm the potential of VDN decision-making systems to drive advancements in UUV communication technologies.

A Novel 4 × 1 MISO-VLC System with FBMC-OQAM Downlink Signals

A novel visible-light communication (VLC) system with 4 × 1 multi-input–single-output (MISO) channels is designed. In the system, the filter bank multicarrier (FBMC) and offset quadrature amplitude modulation (OQAM) techniques are used to generate downlink signals. The principles and implementation methods are proposed and analyzed, and the light intensity and received light power distribution of four LED emitters are discussed. The results demonstrate that it not only satisfies the requirements of indoor information access but also provides daily lighting. The used FBMC-OQAM signals exhibit better reception performance than orthogonal frequency division multiplexing (OFDM) signals. The system used has a lower bit error rate (BER) and larger access bandwidth compared to a 1 × 1 single-input–single-output (SISO) system. It has the potential for application advantages in future indoor VLC system applications.

Channel estimation techniques based on intrinsic interference mitigation for FBMC/OQAM systems

Filter bank multicarrier with offset quadrature amplitude modulation (FBMC/OQAM) emerges as a noteworthy alternative to orthogonal frequency division multiplexing (OFDM). FBMC/OQAM addresses the limitations of OFDM by utilizing real-valued, even-symmetrical prototype filters with smaller side lobes and faster spectrum decay. This results in lower out-of-band energy and higher spectral efficiency (SE). However, the orthogonality condition of FBMC/OQAM in the real domain introduces an intrinsic interference (II) component that poses challenges for channel estimation (CE). The conventional straightforward OFDM CE techniques cannot be applied directly. To obtain a precise CSI with the FBMC/OQAM system, Kalman filter (KF) is altered and incorporated into the use of AP and coding. The first proposed method, KalCod, employs a data spreading method to diminish the II effect. The simulation results indicate that KalCod has a superior capacity to the other CE methods, while still maintaining a reasonable level of complexity. In the second proposed method, modified Kalman-auxiliary pilot (KAP), an AP is used to eliminate the II at pilot symbols then updating the channel coefficients using modified KF. When used as a CE method for FBMC/OQAM systems, the modified KAP outperforms its competitors in terms of estimation accuracy, simpler implementation, as well as higher throughput and spectral efficiency.

Novel Orthogonal Time Frequency Space Based on Universal Filter Multi Carrier for 6G Wireless Networks

Obtaining an efficient multicarrier signalling technique is an essential part in signal processing of the (6G) wireless networks. In order to achieve their intended objectives, the 6G mobile networks needs the utilization of a multicarrier scheme that possesses the ability to withstand multipath fading and inter-symbol interference (ISI), as well as exhibit resilience against inter-carrier interference (ICI) and Doppler spread. In recent research, several filter-based methods have been suggested, including Filter Bank Multicarrier (FBMC), as well as various Orthogonal Frequency Division Multiplexing (OFDM) based techniques such as Universal Filtered Multicarrier (UFMC). Orthogonal Time-Frequency Space (OTFS) technique has been identified as a promising candidate waveform for 6G, particularly in high-mobility scenarios, where it has demonstrated superior performance compared to traditional OFDM-based techniques. The OTFS method offers an advantage in that it can be considered the pre-and post-processing stages for techniques based on OFDM. This papaer presents the design (OTFS) using (UFMC) technique. Additionally, a novel structure is proposed for coded/uncoded UFMC-based OTFS technique, which combines the advantages of both strategies while mitigating their limitations. The results of our analysis demonstrate that the UFMC-based OTFS system exhibits superior performance in terms of error probability and time-spectral efficiency compared to the OFDM-based OTFS system.

Simulation and analysis of 5G waveforms to reduce BER for vehicular communications

In today's rapidly evolving world, wireless communication has become a pervasive force, profoundly impacting various facets of our daily lives. Wireless Vehicular Networks stand out as a captivating realm of research, with a key focus on fostering information exchange among autonomous vehicles. As researchers witness surging demand in this domain, there is a growing emphasis on devising advanced techniques to augment network performance, particularly within the context of Fifth-generation (5G) applications, such as vehicular communication. The concept of Vehicle-to-vehicle (V2V) communications is poised to play a pivotal role in the future, presenting formidable challenges for the air interface by accommodating asynchronous multiple access and high mobility. Within this dynamic landscape, security and privacy issues loom large for 5G-enabled vehicle networks, many of which remain largely unexplored. The conventional waveforms, including Orthogonal Frequency Division Multiplexing (OFDM), may fall short of meeting these evolving standards. In this paper, authors delve into a comparative exploration of two waveform families, namely Filter Bank Multicarrier (FBMC) and Universal Filtered Multi-Carrier (UFMC), concerning their design and performance trade-offs. authors also examine their compatibility with various digital modulation schemes like 4-Quadrature Amplitude Modulation (QAM), 16-QAM, Offset Quadrature Phase Shift Keying (OQPSK), and Shaped offset OQPSK (SOQPSK). Through MATLAB simulations, our research vividly demonstrates the superior performance of UFMC when juxtaposed with OFDM and FBMC, especially concerning Bit Error Rate (BER) in both Rayleigh and Nakagami fading channels. In particular, authors consider a Nakagami shape parameter of 10, which yields a remarkable minimum BER for UFMC.

Performance enhancement of multiple-mode FBMC-IM VLC systems with group-interleaved precoding

In this paper, we introduce the application of multiple-mode index modulation (MMIM) to filter bank multi-carrier (FBMC) for the first time in visible light communication (VLC) systems. Additionally, we propose a group-interleaved precoding (GIP) technique to enhance the performance of MM-FBMC-IM-based VLC systems. The GIP technique reduces complexity in precoding by grouping and achieves equalization of the signal-to-noise ratio (SNR) through subcarrier interleaving. Furthermore, we develop a robust low-complexity maximum likelihood (LCML) detector, which can maintain the same computational complexity as a conventional LCML detector and achieve similar performance as an ML detector. The effectiveness and superiority of the proposed MM-FBMC-IM-based VLC system with GIP are demonstrated through comprehensive validation by both simulation and experimental results.

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.

Analysis of Filtered Multicarrier Modulation Techniques Using Different Windows for 5G and Beyond Wireless Systems

In contemporary wireless communication systems, multicarrier modulation schemes have become widely adopted over single-carrier techniques due to their improved capacity to address challenges posed by multipath fading channels, leading to enhanced spectral efficiency. Orthogonal frequency division multiplexing (OFDM), a prevalent multicarrier scheme in 4G, is favored for its ease of implementation, interference resilience, and high data rate provision. But it falls short of meeting the requirements for 5G and beyond due to limitations such as out-of-band (OOB) emissions and cyclic prefixes. This paper introduces the filter bank multicarrier (FBMC) and universal filtered multicarrier (UFMC) with quadrature amplitude modulation (QAM) and phase shift keying (PSK) waveforms through Additive White Gaussian Noise channel (AWGN), Rayleigh fading channel and Rician channel. The objective of this paper is to enhance the performance of UFMC with reduced complexity through the new filtering approach for achieving optimal outcomes. The proposed scheme, incorporating Tukey filtering technique, demonstrates superior performance in reducing peak-to-average power ratio (PAPR) and improving bit error ratio (BER) compared to the original UFMC signal without necessitating additional power increments. Specifically, the UFMC system with Tukey filtering achieves a notable net gain of 5 dB. Simulation results demonstrate that utilizing various filter types in FBMC and UFMC systems, combined with QAM modulation, significantly reduces OOB emissions compared to conventional systems. In aspect to BER, Tukey window showed almost 10−6 at 15 dB SNR in UFMC which is better than FBMC.

PAPR analysis in OTFS using the centre phase sequence matrix based PTS method

Orthogonal time–frequency space (OTFS) is a multicarrier modulation technique for high-speed data transfer in wireless communications. In an OTFS system, many subcarriers are used to send the modulated symbols. This makes OTFS signals have a high peak-to-average power ratio (PAPR). We suggest a partial transmit sequence (PTS) approach based on the Centre Phase Sequence Matrix (CPSM) to lower the high PAPR. Furthermore, the suggested method effectively searches for the best possible combination of phase rotation factors to reduce computing complexity. We examine the outcomes regarding bit error rate (BER), power spectral density (PSD), and PAPR to validate the competing transforms in the OTFS system. Along with non-orthogonal multiple access (NOMA), filter bank multi-carrier (FBMC), universal filter multi-carrier (UFMC), and orthogonal frequency division multiplexing (OFDM), the PAPR, BER, and PSD performance of OTFS were also compared. According to the data, the suggested PTS + CPSM reduces PAPR more effectively than the current PTS. It is also mentioned that by increasing the number of sub-blocks (s = 2 and 4), the suggested PTS + CPSM can achieve an even better PAPR rate. According to the experimental results, the suggested approach has dramatically decreased the PAPR while maintaining the BER and PSD performance with the least amount of computational complexity.

Reconfigurable Intelligent Surface-based Propagation Control in FBMC/OQAM Systems

In this paper, transmission of filter bank multi-carrier (FBMC) modulated signal through reconfigurable intelligent surfaces (RIS) is proposed as an assuring technique for future wireless communication. RIS deliberately alters phases of incident signals to enhance quality of the received signal. Simulation outcomes show that it is possible to establish RIS-based FBMC communications in which RIS functions as an intelligent reflector with information concerning channel phases. It is observed that RIS-based FBMC transmissions may be a prospective solution for beyond 5G communication.

Bi-orthogonality recovery and MIMO transmission for FBMC systems based on non-sinusoidal orthogonal transformation

Filter Bank Multi-Carrier (FBMC) system based on offset Quadrature Amplitude Modulation (offset-QAM) combined with Multiple-Input-Multiple-Output (MIMO) technique faces great challenges. The inherent imaginary interference of FBMC seriously impacts the performance of the Maximum Likelihood (ML) detection technique in MIMO transmission. The application of the Alamouti code is also hindered. In this paper, we present a data-compressed transmission method based on non-sinusoidal orthogonal transformation, which can recover the bi-orthogonality of FBMC and eliminate the imaginary interference. Thereby, the combination of FBMC and MIMO as well as the application of ML technique and Alamouti code are realized. Specifically, we first consider the Walsh transform, which belongs to the non-sinusoidal orthogonal transform, and utilize its property that can reduce the transmission bandwidth to recover the orthogonality of the FBMC in the frequency domain. Secondly, we construct the discrete transmission model of the system and generate the orthogonal compression matrix utilizing the fast Walsh transform. Then, we analyze the multi-frame transmission, calculate the frames interference, and improve the signal-to-interference ratio again by adding guard time slots. Finally, we construct the MIMO transmission model and complete the theoretical analysis. Simulation results show that the proposed scheme has a robust MIMO transmission performance. ML and Alamouti code techniques perform the same as Orthogonal Frequency Division Multiplex in bi-orthogonal FBMC.

A novel piecewise nonlinear companding scaling scheme for FBMC PAPR reduction

The performance of offset quadrature amplitude modulation filter bank multi carrier (OQAM-FBMC) has been noticed to be affected by a high peak-to-average power ratio (PAPR). High PAPR causes the transmit power amplifier to become saturated, improving the bit error rate (BER) and causing out of band (OOB) distortions. In this paper, the PAPR of FBMC systems can be reduced by using shifting and scaling the trigonometric companding technique associated with a reduced BER performance and the power spectral density (PSD) with low OOB distortions. The characteristics of low peak signals are not changed by this companding scheme, while the characteristics of high peak signals are transformed into scaling piecewise nonlinear trigonometric functions. By tuning the parameters the suggested technique maintains the average signal power level unchanged. The theoretical analysis of the proposed scheme is also studied and also compared with the simulation results. The performance of the trigonometric companding scheme is also analysed with the μ-law and A-law existing companding methods and the suggested method obtaining 3 dB and 3.2 dB PAPR improvement respectively. The proposed technique determined to be better in terms of BER performance and spectrum efficiency.

A hybrid approach based on companding and PTS methods for PAPR reduction of 5G waveforms

ABSTRACT As a crucial enabler for the fifth-generation air interface, the filter bank multicarrier with offset quadrature amplitude modulation (FBMC/OQAM) is being investigated by several researchers. This article suggests using partial transmit sequence (PTS) and companding to create a hybrid peak-to-average power ratio (PAPR) reduction strategy for FBMC/OQAM signals. In the novel PTS Companding scheme, there are several segments to the data block signal, and the overlapping factor determines the number of data blocks in each segment. To obtain the lowest signal power in each segment, we choose the best data block to broadcast and examine the next overlapping data block concurrently. After that, the segment FBMC/OQAM signal peaks are compressed using companding. Based on simulation results and analysis, the proposed hybrid PTS Companding method in FBMC/OQAM systems may reduce PAPR more effectively than conventional PTS and Companding schemes. According to simulation results, the hybrid process can achieve around 5 dB greater PAPR performance than the conventional PTS and companding schemes.

Performance enhancement and PAPR reduction for MIMO based QAM-FBMC systems.

Filter Bank Multi-Carrier (FBMC) is attracting significant interest as a multi-carrier modulation (MCM) approach for future communication systems. It offers numerous advantages in contrast to Orthogonal Frequency Division Multiplexing (OFDM). Nonetheless, similar to many other MCM techniques, FBMC encounters a significant challenge with a high Peak-to-Average Power Ratio (PAPR). Additionally, incorporating Multiple-Input and Multiple-Output (MIMO) into FBMC presents heightened difficulties due to the presence of complex interference and increased computational complexity. In this paper, we first study the performance analysis of MIMO based Quadrature Amplitude Modulation (QAM)-FBMC systems considering the system complexity and interference. To enhance coverage effectively using beamforming with multiple antennas, it is essential to reduce PAPR to minimize the input backoff (IBO) required by nonlinear power amplifiers. Therefore, we propose new PAPR reduction method for MIMO based QAM-FBMC systems leveraging the null space within the MIMO channel using clipping and filtering (CF) technique. The PAPR reduction signals generated in this process are then mapped to the null space of the overall MIMO channel for each frequency block. Through computer simulations using a nonlinear power amplifier model, we illustrate that the proposed method substantially enhances both PAPR and throughput of MIMO based FBMC systems compared to conventional methods.