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To improve communication network efficiency, researchers must look at all aspects of transmission and the mechanisms that regulate their evolution as a whole. These features include solutions for dealing with the channel's noise and interference. To decrease interference and increase spectrum efficiency, orthogonal frequency division multiple access (OFDMA) systems employ orthogonal signals. While transmitting and receiving signals, noise and numerous feeds can be done in diverse ways. It has become increasingly common to use 256 quadratic modulation (QAM), which is more vulnerable to noise and has a higher bit error rate (BER). BERs in OFDM systems were high when multiple feeds and noise were present, as demonstrated in this article. Starting with the transmission and reception of Gaussian subband signals, an improved system has been designed that includes numerous stages of development. Thus, the need for "orthogonally" of transmitted signals to increase spectrum efficiency has been eliminated, as has the effect of surrounding channels. We have created a header for every frame that has been transmitted. Several transmitters and numerous receivers send these frames in parallel so that the channel state information (CSI) attributes may be evaluated using parallel processing. Using the identical transmission conditions for both OFDM systems and the proposed system, the simulation results reveal a significant reduction in BER values. This results in BER values of fewer than 10−1 when there are two tabs and 10−1 when there are three tabs for multiple feeding in the OFDM system. This corresponds to BER values of 10−11 in a suggested system when there are three tabs. Some improvements have been made to the proposed design to make it distinctive and qualified to be regarded as a multiaccess system in today's contemporary communication infrastructures. [ABSTRACT FROM AUTHOR]

Summary: The performance of millimeter‐wave (mmWave) multiple‐input multiple‐output (MIMO) systems has been significantly enhanced by the incorporation of dynamic reconfigurable intelligent surfaces (RIS). This paper proposes a novel dynamic channel estimation technique that combines dynamic atomic norm minimization with dynamic RIS to optimize RIS‐aided mmWave MIMO systems. Leveraging the dynamic nature of both atomic norm minimization and RIS, the proposed approach efficiently adapts to changing environmental conditions, providing robust and accurate channel estimation. By dynamically optimizing the RIS configuration, the system achieves improved spectral and energy efficiency, enabling high‐speed and reliable communication in challenging mmWave environments. Theoretical analysis and simulation results demonstrate the effectiveness of the proposed dynamic channel estimation technique, highlighting its potential for enhancing the performance of future wireless communication systems. [ABSTRACT FROM AUTHOR]

Genomic integrity is critical for cellular homeostasis, preventing the accumulation of mutations that can drive diseases such as cancer. Among the mechanisms safeguarding genomic stability, the Base Excision Repair (BER) pathway plays a pivotal role in counteracting oxidative DNA damage caused by reactive oxygen species. Central to this pathway are enzymes like 8-oxoguanine glycosylase 1 (OGG1), which recognize and excise 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) lesions, thereby initiating a series of repair processes that restore DNA integrity. BER inhibitors have recently been identified as a promising approach in cancer therapy, increasing the sensitivity of cancer cells to radiotherapy and chemotherapy. By exploiting tumor-specific DNA repair dependencies and synthetic lethal interactions, these inhibitors could be used to selectively target cancer cells while sparing normal cells. This review provides a robust reference for scientific researchers, offering an updated perspective on small-molecule inhibitors targeting the 8-oxodG-BER pathway and highlighting their potential role in expanding cancer treatment strategies. [ABSTRACT FROM AUTHOR]

A green communication scheme using an orthogonal wavefront (WF) multiplexing (Muxing) scheme spatially combined with orthogonal frequency‐division multiplexing (OFDM) techniques is proposed. It forms a spatial WF OFDM transceiver. The WF Muxing technique serves as the preprocessing and postprocessing method of the WF OFDM transceiver. With coordinated multiple point forward transmission, this spatial WF OFDM system establishes a communication network. It can be applied to multiple base stations (BSs) with down links to single or multiple mobile units (MUs). Although signals are received non‐coherently due to different distances between BSs and MUs, they can be compensated and coherently combined via adaptive equalizers at MUs. This is achieved by using pilot signals with an optimization method at the receiver of MUs. Simulation results demonstrate that the WF OFDM scheme obtains the same bit error rate (BER) as predicted by theory in an additive white Gaussian noise (AWGN) channel. Moreover, the required effective equivalent isotropically radiated power (EIRP) from BSs to the MUs is significantly reduced due to multiple non‐coherent transmission. Accordingly, the interference to adjacent frequency bands' signals will be low. This green communication network is achieved via the combination of WF Muxing, OFDM, and optimization at the receiver together. More investigations are needed to show that this WF OFDM transceiver can be applied to frequency selective mobile fading channels. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of foliar application of calcium and salicylic acid on improving the physicochemical quality, sensory quality and antioxidant potential of pepper fruits grown hydroponically in mineral wool substrate. Two sweet pepper varieties with red fruit type were used: block Aifos and elongated Palermo. Fruit quality was tested from four plant treatment combinations: (1) water (control), (2) calcium nitrate 0.7% (Ca), (3) salicylic acid 0.03% (SA), (4) calcium nitrate and salicylic acid combined (Ca+SA). Fruits of both varieties showed high concentrations of health-promoting constituents, including potassium, phosphorus, vitamin C (over 47 mg 100 g−1 of FW (fresh weight)), and carotenoids, with capsanthin being the most abundant (more than 1226 μg 100 g−1 of FW). The results of the sensory evaluation demonstrated that the attributes tested scores above 7 out of 10, indicating a high sensory quality. The antioxidant activity of pepper fruits was determined by three different methods: DPPH (method for measuring the antioxidant activity of DPPH), ABTS (method for measuring the antioxidant activity of ABTS) and TPC (total polyphenol content) and averaged more than 86%, 78% RSC (radical scavenging capacity) and almost 54 mg CE (catechin) 100 g−1 of FW for both cultivars, respectively. Fruit quality results were analysed using PCA (principal component analysis). The first two principal components (PC1 and PC2) explained almost 54% of the variation, highlighting the strong correlations of PC1 with dry matter content, soluble sugars, potassium, acidity and sensory characteristics of pepper fruit such as skin hardness and flesh firmness. The application of SA to peppers resulted in an increase in the carotenoid content of the fruit. Furthermore, a notable positive correlation was detected between total sugars and the sugar/acid ratio when Ca+SA was combined in both cultivars. Palermo fruit showed better quality parameters and higher antioxidant activity, making this sweet pepper variety particularly valuable in a health-promoting context. [ABSTRACT FROM AUTHOR]

In this paper, An UWOC system using a hybrid LD/LED link is proposed. A simulation was assumed to study the quality of the received optical signal with different modulation schemes such as 64-PPM, 4-QAM, NRZ-OOK, and RZ-OOK. A total of 64-PPM modulation schemes have enhanced the distance link compared with other modulation schemes. PIN and APD PDs are employed to validate the quality of the received optical signal under different water depths. Various metrics of BER, Q. factor, and data rate was introduced to assess the reliability of the hybrid LD/LED link. The simulation results show the proposed system can be achieved a good link with different water depths. The attenuation coefficient of water varies with depth and restricted the performance link distance by hybrid LD/LED link. The 64- PPM is a suitable modulation scheme for getting a long-distance link. The photodetector APD PD outperforms the PIN PD when 64-PPM and 4-QAM are applied. [ABSTRACT FROM AUTHOR]

In this paper, the hybrid LD/LED link for the UWOC system is proposed. The Three different wavelengths, namely 715, 532, and 412 nm are adopted as a carrier signal at different water depth variations. A simulation was carried out to assess the quality of the received signal based on bit error rate (BER), quality factor (Q. factor), and data rate. The results indicate that the suggestion system can achieve a good link with different water depths. In addition, the APD PD is better than the PIN PD. The enhancement in the maximum distance link can be achieved with an LD link. [ABSTRACT FROM AUTHOR]

To achieve high data rate, futuristic wavelength division multiplexing passive optical network (WDM-PON) has pursued due to capability of multiplexing individual wavelength. This paper illustrates the possibility of different data rates along with distance to solve the challenges for next-generation WDM-PON systems. It is superior to present PON design due to rapid progress in different passive components for access network. In this paper, recent progress such as 20 Gb/s (gigabits per second) to 80 Gbps. WDM-PON technology has been carried out. Due to recent development in PON systems, demonstration of 80 Gbps (10 Gbps per wavelength * 8) based WDM-PON system with simplified and optimized design for last mile is presented. The simulation results have been compared to demonstrate the effect of the results achieved. At last, better quality (Q)-factor of 3.46, low value of BER (bit error rate) i.e., 2.48 × 10−11 with reach of 80 km whereas high value of Q-factor of 22.16, eye height of 4.75 and BER of 3.61 × 10−10 has achieved successfully using WDM-PON system. [ABSTRACT FROM AUTHOR]

For communication in space, information transmission lines are critical for reaching the whole world. A long delay and a poor data transfer rates have been observed in radio frequency (RF) communication and therefore inter-satellite communication has become more common in recent years and optical wireless communication has advanced dramatically. Owing to its multiple advantages, including large channel bandwidth, high-speed connectivity and economical operations, IsOWC technology is becoming popular among researchers. Uniphase modulations such as NRZ modulation does not have efficient spectrum for high speed inter-satellite communication. PDM-256-QAM at 160 Gbps over IsOWC channel is demonstrated in this work using matched filter and DSP. Proposed system is investigated for PDM-256-QAM at 850 and 1550 nm wavelength and results analyzed in terms of Q factor, log symbol error rate (SER) and error vector magnitude (EVM). [ABSTRACT FROM AUTHOR]

Summary: A comparative analysis of 3D positioning error for two different configurations using different layouts of visible light communication (VLC) systems is presented in this paper. The Received Signal Strength (RSS) has been implemented for indoor localization systems using Line‐of‐Sight (LoS) and diffused reflection signals. The room size for configuration‐1 is 5 m × 5 m × 3 m, and the distance between adjacent LEDs is 2.5 m, 2.00 m, and 1.5 m for cases‐1, case‐2, and case‐3, respectively, whereas the room size for configuration‐2 is 7 m × 7 m × 5 m, and the separation between the LEDs is 3.5 m, 3 m, and 2.5 m for their respective cases. Through investigation, it has been shown that when only LS signal is considered, the separation between LEDs may not be an issue because positioning error changes by a very small amount as the separation between LEDs changes. The results show that as the distance between adjacent LEDs decreases, the received signal strength for LoS and L‐R1 signals increases. However, positioning error and BER rise, while the bit rate falls. Furthermore, the positioning error Vs receiver plane height for all three cases in configuration‐1 is the same up to a height of 2.89 m, whereas the positioning error in configuration‐2 is the same up to 4.4 m for all cases. The positioning error for case‐1 decreases as the height in configuration‐1 exceeds 2.89 m. Similarly, after reaching a height of 4.4 m for case‐2, the positioning error in configuration‐2 decreases. The LoS positioning error versus semi angle φ1/2 of the LED as well as the FOV of the receiver has been simulated for different positions of the receiver in configuration‐1. The investigation shows that the minimum positioning error is achieved at φ1/2 and FOV equal to 66.660 for all the positions of the receiver in the room. Thus, before configuring a practical indoor VLC geometrical model, proper VLC configurations such as LED separation, FOV of the receiver, semi angle of LED, and receiver height should be chosen based on the room dimensions. [ABSTRACT FROM AUTHOR]

This research aims to create trustworthy, fast communication technologies for 5G and beyond. The design investigates the possibilities of Free-Space Optical (FSO) communication systems and MilliMeter-Wave (MMW) technologies operating at 60 [GHz]. Although these technologies are highly effective and have a high throughput, they are nevertheless vulnerable to weather phenomena like rain, fog, and Atmospheric Turbulence (AT). The paper suggests using Space Division Multiplexing (SDM) and the MMW-FSO link to develop optical-radio communication systems. The proposed systems aim to transmit data to four compact 5G Base Stations (BSs) that numerous 5G users can reach. The MMW-RF (Radio Frequency) link uses four MMW frequencies: 58.32, 60.48, 62.64, and 64.80 [GHz]. The present work offers designs based on different forms of optical communication systems. The performances of these designs are assessed using two powerful simulation tools, Matlab and OptiSystem. For the MMW-FSO link, the study analyses the Bit Error Rate (BER), the Communication Capacity (CC), and the RF-spectrum peak power. It additionally takes into account the performances of the MMW-RF link, such as the Required Signal-to-Noise Ratio (RSNR) at 5G users, the Receiver Sensitivity (RS) at 5G users, the BER at 5G users, the CC between 5G BSs and 5G users and Power Efficiency (PE) at 5G users. Data transmission has been tested on various connections of the proposed systems with an acceptable BER of 1e-9 on the MMW-FSO link. Without AT but in the presence of heavy fog, the average CC results obtained are 4.13e + 10 bps, 4.25e + 10 bps, 3.64e + 10 bps, and 4.11e + 10 bps for the first to fourth connections, respectively. With weak AT ( 10 - 17 [m−2/3]) and heavy fog, the average CC results are changed to 2.57e + 10 bps, 2.59e + 10 bps, 3.035e + 10 bps, and 3.15e + 10 bps, respectively. Under conditions of moderate AT ( 10 - 15 [m−2/3]) and heavy fog, the results become: 2.79e + 10 bps, 2.82e + 10 bps, 3.104e + 10 bps, and 3.120e + 10 bps respectively for the same proposed connections. Furthermore, the impact of the attenuation coefficient on the MMW-FSO link, which may have an impact on the performance of the proposed systems on the MMW-RF link between the 5G BSs and 5G users under different weather conditions must be taken into account. Connections one and two of the proposed systems outperform connections three and four in terms of their capacity to accommodate a greater number of 5G users. With an acceptable BER performance of 1e-3, connections three and four can accommodate a maximum of seven 5G users for each 5G BS operating within a bandwidth of 270 [MHz] when assigned distinct time slots. The ultimate goal is to advance next-generation communication technologies for a highly connected society with a manageable number of users. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In the dynamic landscape of the tech industry, the escalating requirement for swift and secure data transmission has catalyzed innovation in integrated communication systems. Free-Space Optics (FSOs) has emerged as a promising contender in optical communications. While conventional optical fiber systems can achieve bit rates of up to 40 Gbps with proper design, they are limited primarily by electronics rather than semiconductor laser capabilities. This study presents an integrated framework that combines FSOs, blockchain technology, and sensor networks to address challenges in data transmission, security, and environmental adaptation. This study analyzes FSOs system performance through the Quality (Q) Factor and Bit Error Rate (BER), comparing systems with and without Erbium-Doped Fiber Amplifiers (EDFAs) across various bit rates (8, 12, 16, and 20 Gbps) and transmission distances (5–25 km). To enhance data security and reliability, a blockchain architecture is incorporated with smart contracts and an InterPlanetary File System (IPFS) for storing and validating results generated from FSOs simulation. Additionally, this study explores the design of sensor network models for FSOs technology by investigating how distributed sensor arrays can be theoretically integrated with FSOs systems, with testing focused on FSOs performance and blockchain implementation. [ABSTRACT FROM AUTHOR]

In this article, we design and implement a multiantenna configured secure multiuser discrete Fourier transform (DFT)-Spread orthogonal frequency division multiplexing (OFDM) system based on frequency-domain spectrum shaping (FDSS) for reconfigurable intelligent surfaces (RISs) and unmanned aerial vehicle (UAV)-assisted terahertz (THz) communications. Our proposed simulated system highlights more suitable performance matrices for a typical case of three users for color image transmission. We introduced a six-dimensional hyperchaotic system-based encryption algorithm to enhance the physical layer security (PLS) of a UAV-to-ground communication network. In addition, the block diagonalization (BD) precoding technique reduces multiuser interference (MUI). Furthermore, we included repeat and accumulate (RA) channel coding with Cholesky decomposition-based zero-forcing (CD-ZF) and minimum mean square error (MMSE) signal detection schemes to improve the bit error rate (BER). We adopted the FDSS scheme and considered null carriers to reduce the out-of-band (OOB) spectrum power. The simulation results demonstrate the effectiveness of the proposed system in terms of PLS enhancement for color image transmission, with a low image structural similarity index of 0.65%, 1.60%, and 0.70% for users 1, 2, and 3, respectively; an achievable OOB power emission of 337 dB; and estimated peak-to-average power ratios (PAPRs) ranging from 7.10 to 7.85 dB at a complementary cumulative distribution function (CCDF) of $1\times 10^{-4}$ for different ground-transmitting channels. At signal-to-noise ratios of 13.7, 9.4, and 7.5 dB, users 1, 2, and 3 achieve a BER of $1\times 10^{-3}$ under RA channel coding, MMSE, and binary phase shift keying (BPSK) digital modulation.

Wide-band wireless communication in tunnels and long corridors faces challenges due to multipath interferences and delay spread. Wall reflections induce dispersion, causing amplitude and phase distortions in the received signal, with the extent of distortion determined by multiple factors. Accurate modeling of space-frequency effects is essential for designing reliable indoor wireless links. This study presents an experimentally validated, precise, and versatile model for the propagation of modulated wireless signals in tunnels. Quasi-optical, multi-ray model is employed to derive the transfer function, describing the indoor propagation in the frequency domain. The model enables analysis of the impact of changes among other in modulations, frequencies, and different bandwidths. The results include a comprehensive comparison of various cases for Bit Error Rate (BER), Error Vector Magnitude (EVM), constellations, and facilitating a thorough examination of the tunnel effects in each scenario. Several representative results are presented in the paper. Notably, a significant correlation is observed between the bandwidth used and an increase in BER. Furthermore, the comparison between Orthogonal Frequency Division Multiplexing (OFDM) and Quadrature Amplitude Modulation (QAM) reveals a distinct preference for OFDM due to its ability to overcome the frequency-selective fading nature of the tunnel.

Abstract Free space optical (FSO) systems offer an attractive and cost-effective solution for providing communication services in remote regions, as they allow secure transmission without the need for licensing and with lower deployment costs. However, the performance of FSO systems can be significantly impacted by atmospheric turbulences, creating considerable challenges to their deployment. To meet the expanding bandwidth requirements in optical networks, dense wavelength division multiplexing (DWDM) has emerged as a viable option. The development of a 400-Gbps DWDM-FSO system with advanced modulation formats is the subject of this paper. To ensure efficient energy conservation in such a system, power consumption needs to be minimized while maintaining performance level; this calls for optimization of different components within the system. The system is made up of 10 channels and each channel can transmit data at 40 Gbps. Various modulation schemes like carrier-suppressed return-to-zero, modified duo binary return-to-zero, differential phase shift keying, and duo binary return-to-zero are studied for their impact on system performance parameters Q-factor and bit error rate (BER) in C-band around 1550 nm wavelengths. The assessment is also extended to the effects that changing FSO length, input power, and data rate have on these two parameters as well as an evaluation regarding how differing atmospheric conditions influence the FSO system’s effectiveness.

One of the primary challenges faced by visible light communication (VLC) systems employing optical orthogonal frequency division multiplexing is the peak-to-average power ratio (PAPR). This study is dedicated to designing, simulating, and evaluating bit error rate (BER) and PAPR reduction methods tailored for the VLC broadcasting system. The asymmetric clipped optical orthogonal frequency division multiplexing (ACO-OFDM) scheme is highlighted in this work for its impressive performance. Therefore, the proposed PAPR mitigation methodologies applied to ACO-OFDM. The proposed PAPR reduction strategy involves 5 distinct precoding methodologies. The PAPR was mitigated by 3.485 dB after applying the DST precoding methodology. Still, the WHT precoding methodology can achieve PAPR reduction by 1.131 dB, without BER performance degradation, with respect to the conventional ACO-OFDM system. Furthermore, the work addresses another challenge in VLC systems: the bit error rate (BER). This is accomplished by introducing approaches to Time Domain Noise Cancelation and Frequency Domain Noise Cancelation (FDNC). The BER performance of these 2 receiver models is nearly the same. The simulation results indicate the system performance enhancement after applying noise cancellation approaches by 1.65 dB at the 4-QAM modulation scheme and 2.97 dB at the 1024-QAM modulation scheme. The 16-QAM modulation scheme, after applying DST and WHT methodologies alongside noise cancellation approaches, can enhance both PAPR by 20.83% and 6.76%, but the Eb/N0 performance enhancement by 10.10% and 14.64%, respectively. Additionally, the effectiveness and validity of the proposed schemes are verified by comparing them with relevant literature reviews on PAPR reduction techniques and selecting an optimal choice among them. [ABSTRACT FROM AUTHOR]

Multiple Input Multiple Output (MIMO) Wireless communication uses several antennas in the transmitter and receiver end. Multiple antennas at each end of the communication circuit work together to reduce errors, increase data speed, and improve radio transmission efficiency. MIMO techniques, which increases the number of antennas at the base station, will be used in 5G. Interference between users, which reduces a wireless link's spectral efficiency (SE), poses a major challenge during uplink communications with mm-wave systems. A linear MIMO detector such as maximum ratio (MR) or minimum mean square error (MMSE) cannot resolve this phenomenon. Therefore, this paper proposes a MIMO detection method based on an optimised extreme learning machine neural network (OELMNN). The Adaptive Rat Optimization algorithm is used to optimise the weight and bias values of ELMNN to improve its performance. The proposed scheme's performance is measured in terms of SNR, MSE, BER, and spectral efficiency. [ABSTRACT FROM AUTHOR]

In this article, we explore the use of neural networks (NNs) to enhance the performance evaluation of Universal Filtered Multi-Carrier (UFMC) systems, a key technology for modern communication networks such as 5G and beyond. Traditional methods of evaluating the Bit Error Rate (BER) and system efficiency in UFMC system can be computationally intensive and less accurate under dynamic conditions. To address these challenges, we propose a NN based approach that not only improves the accuracy of BER prediction but also significantly optimizes the system's overall efficiency. Channel state estimation (CSE) plays a major role for UFMC system to address the phenomenon of multipath channel fading. In order to achieve a high data rate using UFMC technology, it is necessary to have an effective CSE and very accurate signal detection. Recently, there has been significant interest in utilizing deep learning (DL) to enhance channel estimations. This article introduces a new method for channel estimation (CE) in UFMC system. The suggested approach utilizes DL models to improve the CE. For the UFMC system, we propose a detector based on bidirectional long short-term memory (Bi-LSTM). To identify the transmitted symbols, the suggested detector uses DL training data directly. Currently, a significant drawback of UFMC systems is the presence of a high peak-to-average power ratio (PAPR). The approach aims to reduce the BER and enhances the efficiency of the UFMC system. This is achieved by dynamically setting the constellation mapping and symbol damping on each subcarrier and sub-symbol. The results illustrate that the proposed model can accurately and efficiently recognize UFMC signals. The suggested model is being compared to Least Square (LS), LSTM, and Minimum Mean Square Error (MMSE) channel estimators. Through extensive simulations, our results demonstrate that the NN model reduces BER and enhances efficiency. The proposed model gives more effective performance in terms of enhanced efficiency and reduction of BER. The findings offer valuable insights for the design and optimization of next-generation communication systems, where accurate and efficient performance evaluation is critical. [ABSTRACT FROM AUTHOR]

Visible light communication (VLC) has the potential of combining the idea of illumination and communication, and that creates the growing interest of using optical communication in recent wireless communication scenario. To any electronic gadgets used by the doctors, the VLC can transfer the medical information through the light emitting diodes (LEDs) installed in the room (indoors) for the purpose of illumination. The broadband transmission technology is supported by VLC. A wireless sensor network (WSN) is a network composed of numerous autonomous sensor nodes that communicate wirelessly to collect and transmit data from the patients. These networks are commonly used in scenarios where it is not practical to use wired communication, or where data need to be collected from remote or inaccessible locations. Cluster nodes reinforcement scheme (CNRS) improves the routing efficiency and also increases the network lifetime. In this scheme, the base station transmits the pilot message to each node, and normal nodes reply back to the pilot message. The work evaluates about end-to-end (ETE) delay of CNRS and BER in binary phase shift keying (BPSK) with DC-biased optical orthogonal frequency division multiplexing (DCO-OFDM) in VLC while transferring the medical details collected through WSN. [ABSTRACT FROM AUTHOR]

This study analyzes the efficacy of radio over free space optics (Ro-FSO) communications over an atmospheric turbulence link. Four transmission channels transmitted information at a rate of 40 GB/s. Each channel carries 10 Gbps of a 20 GHz RF signal modulated with an optical signal from an optical source with a distinct frequency over a gamma-gamma scintillation model. The data were transmitted in parallel, i.e., simultaneously, as a result of altering atmospheric turbulence intensities. Q-factor, min log BER, and eye diagram have been utilized to assess the system's efficacy. The study shows that the wavelengths used for data transmission are affected differently depending on the level of atmospheric disturbances. The simulation results recognized that the most effective wavelength for data transmission is (193,1 THz), followed by (193,4 THz). [ABSTRACT FROM AUTHOR]

The continuous progress in hybrid free space optical/radio frequency (FSO/RF) communication systems has led to their significant potential in addressing the challenges posed by atmospheric turbulence and pointing errors. This paper investigates the strategy for improving the performance of such hybrid systems under these adverse conditions. By employing adaptive modulation and combining techniques, the system adapts to the fluctuating quality of the FSO link due to atmospheric turbulence and the effects of pointing errors. The utilization of exponentiated Weibull (EW) and Rician distributions accurately models the fading in FSO and RF channels, respectively. Through rigorous analysis, this study establishes closed-form expressions for outage probability and average bit error rate (BER), providing insights into the system's performance. Furthermore, the study investigates the influence of various parameters, including the FSO and RF link's SNR, turbulence conditions, and pointing error parameters, on system performance. The results demonstrate a significant enhancement in system performance. Specifically, for an outage probability of 10 - 2 , the proposed scheme improves performance by 6 dB compared to the FSO link and by 7 dB compared to the hard-switching scheme. Furthermore, at an SNR of 10 dB, the proposed scheme enhances the BER system performance by 10 - 5 and 10 - 8 compared to hard-switching and the FSO link, respectively. The implementation of adaptive modulation improves the BER system performance by a factor of 10 - 5 compared to using BPSK modulation. Hence, the proposed system boosts the quality of service (QoS) by a factor of 99.99 % . [ABSTRACT FROM AUTHOR]

In order to examine the 5G enhancement, this work generates a variety of Filtered-Orthogonal Frequency Division Multiplexing (F-OFDM) waveforms. Windowed-Sinc filters are studied to deploy waveforms in real time. The Blackman-Harris window and the Bohman window have been combined to create a new window, which has been studied. Waveforms built utilizing this window have been compared to traditional Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) waveforms using the MATLAB evaluation package. Data from simulations reveals a number of tradeoffs between bit error rate (BER) and power spectral density. The designer, however, has some leeway in how the window is used. However, BER and power spectral density (PSD) measurements demonstrate that the windows chosen for this work nearly outperform the CP-OFDM signal. Compared to the central lobe, the sidelobe PSD of CP-OFDM is found to be close to -50dBW/Hz. However, -214.177 dBW/Hz is the value obtained for the new-window. [ABSTRACT FROM AUTHOR]

The joint beamforming optimization from the perspective of the bit error rate (BER) in a reconfigurable intelligent surface (RIS)–assisted intelligent communication system is studied in this paper. A genetic algorithm (GA) is investigated to address the bottleneck of the system performance based on the dynamic adaptability theory. However, the bottleneck is caused by the interaction between the active and passive beamforming. To tackle the constraints of conventional optimization approaches, the hybrid scheme is proposed to combine the GA optimization (GAO) and fully connected neural network (FCNN) strategy. Specifically, the intelligent collaborative tuning of system parameters is achieved using this proposed technique. Simulation findings indicate that the hybrid scheme not only simplifies the calculation process to obtain the optimal network parameters, but also effectively optimizes the system structure by dynamically adjusting the RIS reflection configuration. Based on this, the signal transmission quality is improved, interference is reduced, and the stable and efficient operation of the RIS–assisted intelligent communication system is ensured in the complex wireless transmission scenario. [ABSTRACT FROM AUTHOR]

This paper analyzes the effects of turbulent structures of different sizes on the structural parameter of the refractive index and, consequently, on the scintillation index of radio waves passing through atmospheric channels with fading. The relationships between these parameters are analyzed and discussed not only for weak turbulence, but also for moderate and strong turbulences occurring in the mid‐latitude troposphere. By using the relationship between the scintillation index of signal intensity and the well‐known Rician K $K$ parameter of fast fading, and by obtaining the relationships between the signal data stream parameters, capacity, spectral efficiency, and bit error rate, and K $K$ factor of fast fading, we have numerically analyzed various cases of data transmission over tropospheric communication links with fading. This analysis considers the effects of weak, moderate, and strong turbulence on the quality of data transmission over such communication links. The results of this study can be used to improve the design and performance of tropospheric communication links in the presence of turbulence. Key Points: Analyzing the effects of turbulent structures of different sizes on the structure parameter of the refractive index and, consequently, on the scintillation index of the radio wave passing through atmospheric channels with fadingWe consider both weak and strong turbulenceWe link between the effects of turbulence and communication parameters, such as, channel capacity, bit error rate and spectral efficiency, using the Rician K $K$ factor of fading [ABSTRACT FROM AUTHOR]

Underwater wireless communication stands as a captivating and swiftly progressing domain in recent. To support higher data rate and higher bandwidth applications, there is significant attention towards underwater acoustics along with Visible Light Communication (VLC) technology. Underwater sensor networking serves as the backbone of oceanic exploration efforts. Based on the traffic load and underwater environmental conditions, an appropriate communication link can be selected to achieve higher data rate. Acoustics supports communication over longer distances with lower data rate. Despite offering higher data rates, Visible Light Communication (VLC) faces limitations in terms of communication range, proving to be relatively short compared to other methods. A seamless transition is anticipated during data transmission and reception by employing Light Emitting Diodes (LEDs) and photo detectors on the optical-acoustic channel, bridging the gap between acoustic and optical communication methods. Utilizing MIMO-based Enhanced Reverse Polarity Orthogonal Frequency Division Multiplexing (MIMO-ERPO-OFDM) in Underwater Optical Communication (UWOC) proves to be a superior approach, achieving a high throughput of 19.9 Mbps and a lower Bit Error Rate (BER) of 10− 1. [ABSTRACT FROM AUTHOR]

Future wireless networks extensively employ the two-dimensional Optical-Orthogonal Time Frequency Space (O-OTFS) modulation system due to its increased dependability, flexibility, and data throughput. When there is a lot of movement, OTFS offers improved connectivity performance. While OFDM functions in the time-frequency domain, O-OTFS modulation acts in the delay-Doppler domain. This study provides an overview of how OTFS functions in the delay-Doppler domain, as well as its benefits and drawbacks. Next-generation networks utilize this modulation method in various applications, such as vehicle-to-vehicle communication, communication in mountainous areas, high-speed mobility, and train communication. This paper provides an easy-to-understand overview of the PAPR algorithms and its reduction in O-OTFS modulation. [ABSTRACT FROM AUTHOR]

This study provides a comprehensive analysis of the design and performance evaluation of a radio over free space transmission link using Optisystem v.20 software. The research focuses on the integration of four transmission channels through the use of a multiplexer to achieve a transfer rate of 40 Gbps over a distance of 2 km, with each channel carrying 10 Gbps of data. This is achieved by modulating data on 20 GHz radio frequency signals, which are subsequently transmitted via laser waves at different frequencies. The performance of the proposed communication is assessed by evaluating its behavior in the presence of different levels of atmospheric turbulence, classified as light, medium, and strong. This analysis involves calculating based on metrics such as the Q-factor, bit error rate (BER), and log values (BER). The results showed that the Q factor decreased by (4.7) under the influence of a strong disturbance, while in contrast, it decreased by (0.2) under the influence of a weak disturbance. The results also indicated a minimum log BER (at −7.96) for the wavelength (193.3 THz) at 1.5 km. Besides, the best frequency for data transfer was (193.1 THz), followed by (193.4 THz). [ABSTRACT FROM AUTHOR]

This work has clarified the high efficiency coupling fibers with different types of photo detectors for the management of noise multiplication and efficient bandwidth. As well as the study of the base band signal to noise base band form ratios are clarified with EDFA base band amplifier length variations. Max Q form factor with EDFA amplifier base band length variations is also demonstrated. The optimum base band electrical signal form power is simulated with EDFA base band amplifier length variations. The simulative study of Ge and InGaAs PIN photo-detectors performance evaluation are studied in the presence of the soliton transmission fiber systems. The dispersion management by the soliton technique to reach the value around zero. The max base band signal power form is clarified versus time based Ge and InGaAs PIN photo-detectors. Total base band electrical power form based Ge and InGaAs PIN photo-detectors are demonstrated. Max signal base form power amplitude band is simulated with the spectral base band frequency based Ge and InGaAs PIN photo-detectors. The max signal base form power amplitude band is studied versus time based Ge PIN photo-detectors. [ABSTRACT FROM AUTHOR]

This paper is successfully demonstrated simulative comparison and investigation of 32 channels with 0.8 nm frequency spacing bidirectional wavelength division multiplexing passive optical network (WDM-PON) having 640 and 320 GB/s data rate in downstream and upstream transmission by using CRZ-DPSK/NRZ modulation formats respectively. The maximum reach of the system has been configured to 100 km by employing different post-dispersion compensation techniques such as EDC, DCF, OPC, and FBG in uplink and downlink transmission for compensate the effect of chromatic dispersion in propagating channel. An EDFA optical amplifier is placed after DCF for boosting the amplitude of weak signals downstream. Apart from this, the RSOA amplifier is installed at the ONT end for reflecting and re-modulates the same wavelengths to the CO terminal without using any external optical light source. The performance comparison of distinct compensation schemes are evaluated in terms of BER, Q factor, and Eye diagrams. It has been observed that the FBG and DCF are more robust compensation techniques as compared to EDC and OPC in the bidirectional WDM-PON. The maximum satisfying value of BER has been observed in downlink and uplink transmissions are 10−26 and 10−13 for FBG and DCF respectively. [ABSTRACT FROM AUTHOR]

One of the most critical challenges in optical fiber communication systems using non-orthogonal multiple access (NOMA) techniques is reducing the peak-to-average power ratio (PAPR). Optical NOMA often leads to high PAPR, causing non-linear distortion and limiting the system's gain. The advanced Selected Mapping (SLM) algorithm is introduced in this work to reduce the PAPR of the O-NOMA. In conventional SLM, multiple phase sequences are applied to the input data, which requires numerous Inverse Fast Fourier Transform, increasing computational complexity. The proposed approach simplifies this by selecting a central reference phase sequence, reducing the number of candidate sequences and the number of IFFT operations required. This reduction in complexity does not significantly compromise the PAPR reduction capability, making the method more efficient. The SLM algorithm addresses this issue by applying the phase rotation factor to the transmitted signals, redistributing the power, and reducing the peak levels. This article highlights the benefits and challenges of implementing SLM in optical NOMA systems, including its compatibility with existing NOMA schemes. Matlab 2016 analyzes parameters such as bit error rate (BER), PAPR, and out-of-band radiation. A 66% PAPR reduction can be obtained using the suggested SLM with various phase variables. Furthermore, there is a −2650 reduction in spectrum leakage. The simulation outcomes of the work reveal the potential of SLM to reduce PAPR and enhance the BER and PSD performance of optical NOMA compared with the existing algorithms. [ABSTRACT FROM AUTHOR]

The Discrete Cosine Transform (DCT) can be used instead of the conventional Discrete Fourier Transform (DFT) for the Orthogonal Frequency Division Multiplexing (OFDM) construction, which offers many advantages. In this paper, the Multiple-Input-Multiple-Output (MIMO) DCT-OFDM is enhanced using a proposed Cosine Domain Equaliser (CDE) instead of a Frequency Domain Equaliser (FDE). The results are evaluated through the Rayleigh fading channel with Co-Carrier Frequency Offset (Co-CFO) of different MIMO configurations. The average bit error probability and the simulated time of the proposed scheme and the conventional one are compared, which indicates the importance of the proposed scheme. Also, a closed formula for the number of arithmetic operations of the proposed equaliser is developed. The proposed equaliser gives a simulation time reduction of about 81.21%, 83.74% compared to that of the conventional Linear Zero Forcing (LZF)-FDE and Linear Minimum Mean Square Error (LMMSE)-FDE, respectively, for the case of a 4 × 4 configuration. [ABSTRACT FROM AUTHOR]

Sparse Ramanujan Sequences (SRS) are periodic series derived from Ramanujan Sums (RS). RS is an exponential summation used to derive infinite series expansions for arithmetic functions, whose application pervades different fields of study from classical mathematics to digital signal processing. SRS has properties similar to RS such as periodicity and orthogonality. SRS transforms allow the sparse representation of signals, hence they have many potential applications, such as denoising and compression. The application of SRS transform to reduce the Peak to Average Power Ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) is proposed in this paper. The Complementary Cumulative Distribution Function (CCDF) and Bit Error Rate (BER) are used to assess the PAPR reduction performance of the proposed system. The results show that the proposed SRS transform-based OFDM system significantly reduces PAPR and BER with reduced computational complexity in comparison with the existing systems. [ABSTRACT FROM AUTHOR]

We report the designing of a free-space-optics (FSO) transmission system capable of transmitting high rate information by utilising novel mode division multiplexing (MDM) transmission technique. In the work reported, 2-channels transmitting 10 Gbps data, using either non-return-to-zero (NRZ) encoding scheme or return-to-zero (RZ) encoding scheme are modulated by using different Hermite–Gaussian (HG) modal beams of the single laser beam to realize of 20 Gbps transmission system. The system proposed is simulative analysed under the effect of different weather states. Also, we have compared the bit error rate (BER) and Quality factor (Q Factor) performance for RZ and NRZ encoding schemes in the system for varying weather states. The results reported show that NRZ encoding exhibits a superior performance. Also, we have analysed the system performance by taking into consideration atmospheric scintillation effect and the reported results show notable signal degradation in the presence of scintillation. [ABSTRACT FROM AUTHOR]

This study presents a thorough evaluation of satellite downlink performance in a Free Space Optics (FSO) system with a Low-Density-Parity-Check (LDPC) based Multiple-Input-Multiple-Output (MIMO) configuration. Atmospheric turbulence is characterized using a generalized K-distribution and a negative exponential distribution, with specified parameters. Key performance metrics including Bit Error Rate (BER), outage probability, and accuracy are measured. To address pointing-errors (PEs) and atmospheric turbulence (AT), a novel decoding methodology for Non-Recursive Convolutional Polynomial Encoding (NRCPE)-based Pulse Position Modulation (PPM)-Gaussian Minimum Shift Keying (GMSK)-modulated FSO transmissions is introduced, leveraging Support Vector Machines (SVM). The study introduces a sophisticated Meijer-G function for MIMO statistical analysis and proposes a power series-based Probability Density Function (PDF) with non-recursive GMSK modulation. This PDF allows closed-form derivation of BER and Outage Probability expressions, showcasing improved MIMO link performance in the presence of PEs and AT. Simulations validate the models, offering insights into their effectiveness across varying turbulence levels. The findings assist FSO-MIMO designers in minimizing PEs,AT and achieving optimal results.Subsequently, authors perform a suppression to BER, Particularly, the optimum beam width factors for p × q | 1 × 2 × 2 , & 2 × 3 , diversity degrees by a p × q | 1 × 1 , as a reference are 81.24%, 87.32%, and 89.61%, respectively, at ε nj = 4.02 and I o = 10 dBm .The proposed MIMO/FSO provides accuracy and an irradiances gain of 13.34dBm,i.e., ε nj = 5.03 at BER 10 - 9 for downlink satellite transmission over SIMO and SISO FSO links. This study provides a comprehensive framework for optimizing FSO communication systems, considering atmospheric turbulence and pointing errors. [ABSTRACT FROM AUTHOR]