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Antennas operating at the high-frequency (HF) band (3–30 MHz) are frequently electrically small due to the large wavelength of electromagnetic waves (10–100 m). However, the bandwidth-efficiency products of passively matched electrically small antennas (ESAs) are fundamentally limited. Wideband HF waveforms using bandwidths of 24 kHz or more have recently received significant attention in military communications applications. Efficiently radiating such signals from conventional passive ESAs is very challenging due to fundamental physical limits on bandwidth-efficiency products of ESAs. However, active antennas are not subject to the same constraints. In this work, we present the design and experimental characterization of a high-power, class-E active ESA with enhanced bandwidth-efficiency product compared to that of passively matched ESAs. Specifically, the proposed class-E active ESA can radiate wideband HF signals with bandwidths of 24 kHz or more at 3 MHz (fractional bandwidths of ≈ 1 % – 4 %), with total efficiencies ranging from 40 % up to 80 % depending on the modulation type and radiated power levels approaching 100 W. Our approach uses a highly efficient, integrated class-E switching circuit specifically designed to drive an electrically small, high-Q HF antenna over a bandwidth exceeding 24 kHz at 3 MHz. Using a high-Q RLC antenna model, we have successfully demonstrated wideband binary ASK, PSK, and FSK modulations with the proposed class-E active ESA. Experimental results indicate that the bandwidth-efficiency product of this class-E active ESA is 5.4–9.8 dB higher than that of an equivalent passive design with the same data rate and bit-error-rate. [ABSTRACT FROM AUTHOR]

The competence of Non-Orthogonal Multiple Access (NOMA) to provide improved spectrum efficiency, support massive network elements, and low latency services make it attractive to Multiple Access (MA) technology for next-generation wireless networks. Single-Carrier Frequency Division Multiple Access (SC-FDMA) is an optimal technique in 4G wireless communication to enhance spectrum efficiency and user capacity. The amalgamation of SC-FDMA with NOMA can become a better choice for wireless communication for 5G and Beyond 5G (B5G). Discrete Wavelet Transforms (DWT) have been a better choice for improving the system's performance due to its outstanding orthogonality and spectral confinement characteristics. This study proposes a transceiver architecture that uses joint Discrete Fourier Transform (DFT) and DWT to outperform existing NOMA systems in terms of Bit Error Rate (BER). The transceiver architecture is symbolized as a joint DFT precoded DWT (JDPD) SC-FDMA NOMA System. Furthermore, we propose a Joint Low Complexity Regularized Zero forcing (JLC RZF) for JDPD SC-FDMA NOMA system to enhance the BER with low complexity. In order to illustrate the superiority of the proposed system over multipath channels, the system performance over a range of Carrier Frequency Offset (CFO) values and power allocation scenarios are also examined. [ABSTRACT FROM AUTHOR]

Flash memory, ubiquitous in diverse electronic devices, confronts persistent challenges stemming from inherent errors that jeopardize data integrity. This research situates itself at the intersection of these challenges and advancements, proposing an inventive error correction coding framework that harnesses the unique capabilities of analysis with a hybrid error control coding (HECC) approach. In the proposed work, a mathematical model aimed at enhancing the flash memory by identifying the error pattern within the pages using the discrete fourier transform (DFT). By incorporating distinctive DFT mathematical properties, the proposed technique intends to improve flash memory error correction beyond traditional methods. The flash storage defect detection and rectification results with hybrid error correction coding achieved bit error rate (BER) of 4.3e-6, latency 14.1, mean 15.1 and standard deviation 1.0. Error correction efficiency 98% and storage overhead 10%. With this approach results are significantly improving the error correction efficiency, reduce storage overhead and enhanced adaptability to diverse error patterns. [ABSTRACT FROM AUTHOR]

Summary One of the advanced field in 5G cellular networks is the Massive Multiple‐Input‐Multiple‐Output (MIMO), which creates a massive antenna array by offering numerous antennas at the destination. This grows as a hot research topic in the wireless sectors as it enhances the volume and spectrum usage of the channel. The spectral efficiency (SE) is maximized using the abundant antennas employed by MIMO using spatial multiplexing of consumers, which needs precise channel state information (CSI). The SE is affected by both pilot overhead and pilot contamination. To mitigate the contamination and to estimate the suitable channel for communication, an efficient strategy is introduced using the proposed Namib Beetle Aquila optimization (NBAO)_Deep Q network (DQN). Here, the optimal pilot location is identified by employing NBAO, which is an integration of Namib beetle optimization (NBO) and Aquila optimizer (AO). Moreover, DQN is introduced to determine the suitable channel and metrics, such as bit error rate (BER) and normalized mean square error (MSE) is used for evaluation. The normalized MSE channel estimation is utilized to mitigate the effects of pilot contamination. Additionally, designed NBAO + DQN have attained a value of 0.0006 and 0.0005 for BER and normalized MSE. [ABSTRACT FROM AUTHOR]

Music infringement has emerged as a significant concern and the copyright protection of digital music is becoming more important. Most music copyright protection methods use images as watermark information. Hence, the original watermark needs to be embedded in the music multi-times to achieve copyright protection. It cannot guarantee the accuracy of the embedded watermark. And it may also degrade the quality of the watermarked music. In order to solve that issue, a blind music watermarking is proposed to protect the copyright of music. Comparing with the existing music copyright protection methods, the proposed method generates a watermark from the speech of a copyright owner that can ensure the uniqueness of the watermark. When generating the watermark, the multi-band power distribution of speech recording is calculated first. Subsequently, the discrete cosine transformation is applied to the sub-graphs of the multi-band power distribution, and the watermark is generated using the resulting Discrete Cosine Transformation (DCT) coefficients. After that, the watermark is embedded into the coefficients of Discrete Wavelet Transformation (DWT) using quantization norms. The experiments demonstrate that the Signal to Noise Ratio (SNR) values are higher than 58db between the original music and watermarked music. Meanwhile, the Bit Error Rate (BER) and Normalized Correlation (NC) values are zeros and ones, respectively. In conclusion, the evaluation results show that the proposed method can achieve excellent imperceptibility and robustness. Additionally, it can also effectively resist conventional processing operations such as noise addition, filtering, and so on. [ABSTRACT FROM AUTHOR]

A polarization multiplexing-based long-haul optical communication system using the duo-binary modulation technique is proposed and analysed using numerical simulations. The combination of cascaded dispersion compensation fiber (DCF) and single mode fiber (SMF) is used in the proposed system which effectively minimizes the signal distortion and improves the bit error rate (BER) value and the quality factor (Q-factor) obtained, which indicates the capability of a system to differentiate between the logical 1's and 0's in the receiver section. The system can effectively transmit 10 Gbps data over 120 km SMF along with 24 km DCF as well as 800 m free space optical (FSO) distance for an input power of 10 dBm. The obtained minimum BER value of 3.84 × 10− 10 and the Q-factor of 6.29 proves the efficiency of the system. The obtained results confirm that the nonlinear distortions arising due to increasing the input power are significantly reduced and the optimized result is obtained for 10 dBm input power. The variation of the Q-factor with the effective area of the fiber is also investigated. The achieved BER value of 1.67 × 10− 9 for transmission of 20 Gbps data over a distance of 70 km SMF + 14 km DCF + 800 m FSO proves that the system can be used to transmit high data rate in long-range communication. [ABSTRACT FROM AUTHOR]

In this study, we propose a novel wavelength shift keying (WSK) technique that is combined with the conventional intensity modulation scheme for the transmission of point-to-point bidirectional data at the rate of 10 Gbps in each direction. We observe that WSK technique has not been investigated for implementation in point-to-point free space optical (FSO) links. Therefore, to the best of our knowledge, our study is the first one to perform this investigation. Our proposed link uses WSK in the downlink direction while we re-use the optical carriers for the transmission of uplink data. The use of WSK in the downlink direction enables us to perform balanced detection at the receiver, resulting in 3 dB improvement in receiver sensitivity compared to simple direct detection. We present bit error rate (BER) results for the signals transmitted in both the directions under different turbulence conditions and FSO link lengths. It was observed that the downlink signals generally perform better compared to the uplink due to the use of balanced detection and higher intensity fluctuations induced over the re-used optical carrier transmitted in the uplink direction.Please check and confirm that all the author names (given name, family name) and initials are correctly identified. The author names and initials are CORRECT. [ABSTRACT FROM AUTHOR]

Free-space optical (FSO) communication has become a focus of both study and commercial interest. FSO transfers data between sites in free space, typically the Earth's atmosphere or space, using laser-emitted light beams, in contrast to standard radio frequency (RF) wireless communication. The possibility for high data transmission speeds, the lack of licencing constraints, versatility, affordability, simplicity of deployment, and its environmentally friendly communication method which provides an alternative to crowded radio frequency-based communications are the driving forces behind this growing interest. To determine the feasibility of FSO communication in the cities of Alexandria and Aswan in Egypt, we utilized the micrometeorology model to analyze how weather conditions and atmospheric turbulence impact on FSO linkages based on real-time weather data. In both the winter and summer seasons, we evaluated the bit error rate, beam spreading, scintillation, and transmission range of FSO. Moreover, bit error rate performance was improved by the use of the multi-hop Decode and Forward relay. [ABSTRACT FROM AUTHOR]

Fiber dispersion is a severe constraint to be addressed in high speed optical communication, as it restricts the transmission capacity and reach of fiber optics link. This work presents an effective dispersion compensation technique in the optical domain with minimal hardware complexity. Here, we integrated a single linearly chirped fiber Bragg grating (CFBG) with tanh apodization for Chromatic Dispersion (CD) compensation and a second-order optical FIR filter for Polarization Mode Dispersion (PMD) compensation. Adaptive PMD compensation is obtained by updating the filter parameters using Least Mean Square (LMS) error algorithm, which enables the system to adjust and mitigate PMD effects dynamically, enhancing overall efficiency. The performance of the proposed system with different modulation schemes such as NRZ, RZ, and duo-binary schemes are experimented. A WDM link of 16 channels over 100 km is designed with the proposed model, with each channel transmitting data at 40 Gbps. Simulation results reveal that the presented model performed well with reduced hardware complexity, keeping BER value below 10 - 9 and Q-Factor above 6. [ABSTRACT FROM AUTHOR]

Artificial neural networks (ANNs) have gained a lot of attention from researchers in the past few years and have been employed on a large scale. They have also been gaining momentum in wireless communication systems. For efficient vehicle-to-vehicle (V2V) channel communication, a sparse multipath channel issue must be studied. To minimize the multipath effect, a time reversal (TR) operation and time division synchronization orthogonal frequency division multiplexing (TDS-OFDM) have been appealing because of their fast synchronization and active spectral efficiency. To improve the transceiver's execution in a frequency-selective fading channel environment, an OFDM system is used to reduce inter- symbol interference (ISI). Simultaneous Orthogonal Matching Pursuit (SOMP) channel state estimator algorithm suffer from high computational cost and high computational complexity. The ANN algorithm has better performance than SOMP algorithm. The proposed neural network technologies have lower complexity than the SOMP algorithm. The application of ANN is capable of solving complex problems, such as those encountered in image, signal processing and have been implemented for channel estimation in OFDM. The proposed ANN outperformed the SOMP algorithm with regard to signal compensation. Overall, the ANN algorithm achieved the best performance. This study proposes an ANN-based sparse channel state estimator. Regarding the bit error rate (BER) metric, the proposed estimator outperforms the channel estimation approach based on the SOMP. The simulation results confirm the efficacy of the proposed approach. [ABSTRACT FROM AUTHOR]

The demand for wireless connectivity has grown tremendously over the last few decades. A new perspective of wireless communication will soon be positioned worldwide. In the years beyond, the millimeter-wave spectrum for the mobile communication infrastructure has improved spectral efficiency. The problem of the technical challenges may be detected, identified, and resolved in different designs as traditional solutions involve the software tricks that prevent the modes of operation that trigger the trouble. In this research, we carry out the proposed Millimetre assisted wave technologies using 6G federated learning and high-performance computing for 6G assisted wireless communication systems for voice data optimization. Millimeter-wave technology is a specific part of the radio frequency spectrum, between 24 and 100 GHz. The outcome of this proposed technique will be voice data optimization in the 6G cellular networks for next-generation networks to improve the 6G assisted networks federated learning from existing cellular network technology generation, established on the tool of Flight stack or Autopilot. The observational results express to assess the performance of the device, we acquire theMillimetre assisted wave technologies and federated learning and high-performance computing at various data transmission rates and modulations, including real-time data transfer up to 96 Gbit/s at 420 GHz, with a low bit error rate and good signal-to-noise ratio. With 18 dBm emitted power at 0.4 THz, this method creates and transmits a signal with a 160 Gbits per second net rate across a 15 m distance. This monolithic dual-DFB PIC-based THz generating technique represents an important advancement toward completely integrated, economically viable, and energy-efficient THz transmitters. [ABSTRACT FROM AUTHOR]

The Millimeter-wave and Massive Multiple Input Multiple Output technologies are promising candidates to offer high data rates and system throughputs in the next-generation wireless communication systems. In massive MIMO systems, the precoder plays a leading role to cancel the interference between the data stream and thereby reduce the complexity of the receiver design. In the conventional fully digital precoding scheme, many Radio Frequency chains are essential for every antenna array. Therefore, a hybrid precoder is a feasible solution to reduce the RF chains and improve the antenna array gain by dividing the signal processing into analog and digital precoders. Designing a hybrid precoder is a non-convex optimization problem because the phase shifter in the analog precoder holds hardware constraints. To address this, an intelligent hybrid precoder is designed using deep learning algorithms. In this paper, the Deep Learning framework is incorporated for hybrid precoder as it renovates non-convex problems into a network training process. In this work, the hybrid precoder is based on decomposition techniques such as Uniform Channel Decomposition (UCD) and Generalized Triangular Decomposition method, which is implemented in the training process as it provides equal gain for all subchannels to diminish the inter subchannel interference. The simulation results validate the proposed work is superior in terms of the Bit Error Rate in comparison with other conventional decomposition techniques. The result shows that the deep learning-based hybrid precoder is better than the conventional with a 2 dB improvement between the UCD method and GMD method. [ABSTRACT FROM AUTHOR]

With the development of Internet technology, cyberspace security has become a research hotspot. Network traffic classification is closely related to cyberspace security. In this paper, the problem of classification based on raw traffic data is investigated. This involves the granularity analysis of packets, separating packet headers from payloads, complementing and aligning packet headers, and converting them into structured data, including three representation types: bit, byte, and segmented protocol fields. Based on this, we propose the Rew-LSTM classification model for experiments on publicly available datasets of encrypted traffic, and the results show that excellent results can be obtained when using only the data in packet headers for multiple classification, especially when the data is represented using bit, which outperforms state-of-the-art methods. In addition, we propose a global normalization method, and experimental results show that it outperforms feature-specific normalization methods for both Tor traffic and regular encrypted traffic. [ABSTRACT FROM AUTHOR]

Summary: The technique to overcome the challenge while implementing the fiber optical link is investigated using an alternative optical link called a free‐space optical (FSO) link with advanced modulation and signal processing techniques. A dual‐polarized 16‐quadrature amplitude‐modulated signal is transmitted over single and multi‐FSO channels under various atmospheric attenuation conditions. High bandwidth and data rates (up to 10 Gbps), unlicensed spectrum (above 300 GHz), and simplicity of deployment are significant benefits of the FSO system. However, the weather conditions of haze, rain, and fog cause signal attenuation when the optical carrier wave is transmitted over free space, and atmospheric turbulence is a challenge to FSO implementation, which degrades the transmission performance of optical signals for long‐distance communication. For 120 Gbps data transmission, the performance of a multi‐input and multi‐output (MIMO) FSO system is evaluated by observing the bit error rate (BER) and received signal constellation diagram. Optical signal‐to‐noise ratio (OSNR) parameters were iterated to determine the optimal value for back‐to‐back, single‐input, single‐output (SISO), and MIMO systems. Moreover, we examined the proposed system's output with recent articles, including MIMO, multiplexing, and various modulation techniques. The comparison of results shows that the suggested MIMO‐FSO model has enhanced the performance with the lower BER as less than 3.8 × 10−3 (log of BER is −2.42) forward error correction (FEC) limit for 18.7 km link range in clear air with 0.54 dB/km attenuation, 4.8, 4.5, 1.35, and 0.57 km under haze, light fog, medium, and heavy fog with 4.6, 6.9, 28.9, and 75 dB/km attenuations. [ABSTRACT FROM AUTHOR]

The Wireless Network-on-Chip (WiNoC) technology has emerged as a promising approach to overcome the growing communication constraints present in multi-core systems. Nevertheless, a significant obstacle is presented by WiNoCs' steadily rising energy consumption. In this article, we present a novel method for addressing this issue by combining adaptive joint source coding with low-density parity-check (LDPC) encoding. This strategy is presented as an innovative way to handle the problem. Two key modifications are involved in the implementation of our method: firstly, the accurate tuning of the transform coding threshold in compressive sensing to achieve effective data compression, and secondly, the intelligent control of the number of parity checks in LDPC coding to reduce both energy consumption and latency. These adaptive techniques are tailored to meet the signal-to-noise ratio estimates and the dependability standards unique to the application. Our findings demonstrate a substantial accomplishment, with a remarkable 4.2% reduction in power consumption compared to other methods currently in use. This achievement highlights the vast potential for achieving significant energy savings in real-world applications and is a pioneering contribution to the development of energy-efficient communication systems. [ABSTRACT FROM AUTHOR]

For 6G communications, the Ultra Massive Multiple Input Multiple Output (UM-MIMO) systems with Intelligent Reflecting Surface (IRS) assistance are capable since they can efficiently get beyond the limitations of restricted blockage and coverage. However, in the far field, a robust THz channel sparsity is unfavorable to spatial multiplexing, whereas excessive UM-MIMO and IRS dimensions extend the near field region. To address these issues, a hybrid beamforming IRS assisted UM-MIMO THz system with Deep Siamese Capsule Network is designed with the cascaded channel. The near and far field codebook-based beamforming is developed to model the proposed communication channel. The channel estimation is done based on the deep siamese capsule adaptive beluga whale neural network. The simulation results of the bit error rate, Normalized Mean Square Error (NMSE), spectral efficiency, sum rate, data rate, normalized channel gain, beamforming gain, and array gain loss shows that the proposed system achieves reliable performances compared with existing techniques. The suggested approach also demonstrates the outstanding adaptability to various network configurations and good scalability. The method provides a better channel estimation accuracy and less complexity which shows an NMSE of − 11.2 dB at an SNR of 10 dB. [ABSTRACT FROM AUTHOR]

This paper presents a study of the impact of different types of waveform jamming schemes against remote detonation communication devices based on Long term evolution (LTE) technology. Two main categories of waveform jamming signals (single-carrier and multi-carriers) were used. Also, two jamming scenarios against LTE-based remote detonation devices (jamming the whole LTE frame and jamming the LTE synchronization channel) were investigated. The key point of evaluating the effectiveness of the presented waveform jamming signals is by measuring their ability to successfully cut off the connection between the transmitter and the LTE-based remote detonation device. This is achieved by verifying that the remote detonation device is unable to successfully receive the transmitted information (Deny of Service (DOS) mode). To this end, emulations of these scenarios are held using two Keysight software-defined radio software programs (SystemVue 2015 and VSA 89600). Finally, a real practical experiment of the impact of different waveform jamming schemes against LTE-based remote detonation devices is emulated to present the optimal waveform jamming scheme against these types of devices. [ABSTRACT FROM AUTHOR]

Power estimation has a major impact on the reliability of very-large-scale integration (VLSI) circuits. As a results power estimation is highly needed in VLSI circuits at the early stages. One of the evident challenges in integrated circuit (IC) industry is development and investigation of techniques for the reduction of design complexity due to the growing process variations and reduction of chip manufacturing turnaround time. Under these conditions, the higher design levels of average power estimation before the chip manufacturing process is highly essential for the calculation of power budget and to take the necessary steps for the reduction of power consumption. Over the years, most of the approaches were designed to estimate the power usage, however, most of the conventional techniques are time consuming, resource-intensive and largely manual. Machine learning techniques have received much attention in many of the engineering applications and are capable for modelling the complex systems through historical data. Hence, in this work on chip-based power estimation for complementary metaloxide-semiconductor (CMOS) VLSI using support-vector machine (SVM) is presented to estimate the power. The SVM is employed to estimate the usage of power at runtime. The performance of this model is evaluated in terms of Power usage, delay, data accuracy and error rate. [ABSTRACT FROM AUTHOR]

Summary: An evaluation of various transmit precoding schemes is proposed in this thesis on basis of spectral efficiency (SE) of massive MIMO (m‐MIMO) system in 2 GHz spectrum. The present generation of wireless networks must be rethought due to the rapidly rising user base, huge volume data transfer, wide coverage requirement, and exponential rise in data rate. 5G mobile network includes a multi‐fold increase in network capacity, energy conservation, decreased latency, higher coverage probability, and a seamless connection. m‐MIMO has provided good solution for enhancing the data rate with the coverage, overcoming the effects of multipath fading and has also increased diversity of the system. Massiveness of MIMO system along with 5G network is the key technology to address the issue of SE, throughput, improvement of QoS (quality of service), coverage probability, power delay profile, diversity simulation, energy efficiency, and improvement in bit error rate. Parameters such as SE, throughput, and coverage probability are important for any communication system, and their improvement can increase overall capacity of cellular network system and could meet the requirement of upcoming demand for mobile network. The research paper is focused on performance analysis of m‐MIMO with reference to the SE of various transmit precoding schemes. Simulation results show that SE provided by M‐MMSE (multi‐cell minimum mean‐squared error) technique of precoding ranks highest for the same number of antennas and pilot reuse factor as compared to other schemes. [ABSTRACT FROM AUTHOR]

In order to reduce the impact of electromagnetic interference on signal transmission, the balise uplink signal transmission process and its susceptibility to interference signals were analyzed, and an adaptive demodulation method based on the symbolic least mean square (LMS) algorithm was designed. In order to achieve the demodulation method in the hardware platform, the range of the intermediate variable of the adaptive algorithm of LMS algorithm was determined through simulation calculation. And the weight coefficient was updated by truncation operation. Setting the equalizer length, step factor, and median filter coefficient to 1,1/64, and 16, respectively, can obtain excellent demodulation performance without occupying too much hardware resources. The demodulation algorithm was verified on field programmable gata array (FPGA). The experiment shows that the bit error rate of adaptive demodulation in FPGA is 0. 000 001 when the signal-to-noise ratio is 6 dB. And the measured bit error rate is basically consistent with the simulation bit error rate when the signal-to-noise ratio is greater than or equal to 6 dB. The bit error rate of FPGA adaptive demodulation method is less than 10-6 at different train speed levels. [ABSTRACT FROM AUTHOR]

The integration of large intelligent surfaces (LIS) with non-orthogonal multiple access (NOMA) networks has emerged as a promising solution to enhance the capacity and coverage of wireless communication systems. In this study, we analyse the performance of a NOMA network with the assistance of LIS. We propose a system model where a base station (BS) equipped with a LIS serves multiple users. The LIS consists of many passive elements that can influence the wireless channel by adjusting the reflection coefficients. We consider a downlink scenario where the BS transmits to multiple users simultaneously using NOMA, and the LIS helps to improve the signal quality and coverage. We additionally evaluate the efficiency of the suggested LIS-assisted NOMA network. In addition, we evaluate the efficiency of the LIS-assisted NOMA network in comparison to conventional NOMA systems that do not utilize LISs. The findings indicate that the LIS has a notable impact on enhancing the system's performance in terms of diversity gain, probability of error, and pairwise error probability (PEP). Moreover, the suggested LIS-assisted NOMA network is shown to be superior to conventional NOMA systems through comparison. These findings offer useful insights into the performance analysis of LIS-assisted NOMA networks. They also serve as inspiration and motivation for future research and development in this new subject, with the potential to revolutionize wireless communication systems. [ABSTRACT FROM AUTHOR]

Summary Underwater wireless sensor networks (UWSNs) based on autonomous underwater vehicles (AUVs) have become the standard technology for underwater search tasks with the advent of new underwater information and communication technologies (ICTs). It is also vulnerable to threats and malicious attacks because of its inherent characteristics, open acoustic channel and hostile underwater environment. The purpose of this research is to develop a secure data transfer (SDF) system based on software‐defined networking (SDN) architecture with cooperative searching scheme (CSS) (SDN‐SDF‐CSS) for AUV‐based UWSN. This part employs data, local control and the primary control layer to provide a scalable SDN‐based architecture for the AUV‐based UWSN. To accomplish the underwater search operation, the data layer is primarily deployed to gather AUVs (G‐AUVs) and store AUVs (S‐AUVs). In order to schedule the AUV, the clustering process takes place based on priority ranking with respect to the average power of each cluster. Then, the CSS is developed, and it is performed in the data layer. The hierarchical localization framework (HLF) can be used to locate each AUV's location within the data layer, which is a necessary step in deploying the cooperative searching model. Finally, for an efficient data transfer, the communication model is deployed in the data layer. UWSNs are vulnerable to various malicious attacks (such as bad‐mouthing attacks, on–off attacks, blackhole attacks and wormhole attacks) because of the high bit error rate and unstable optical/acoustic channels in the underwater environment. To overcome this, an SDF technique is used, which involves isolating the attacker node from the data layer. The suggested SDN‐SDF‐CSS model is implemented on the MATLAB platform, and its performance is evaluated using various evaluation metrics, both with and without attacks. As a result, the proposed SDN‐SDF‐CSS model has achieved better performance and proved its superiority in the UWSN environment. [ABSTRACT FROM AUTHOR]

Due to the low-complexity implementation, direction-of-arrival (DOA) estimation-based one-bit quantized data are of interest, but also, signal processing struggles to obtain the demanded estimation accuracy. In this study, we injected a number of noise components into the receiving data before the uniform linear array (ULA) composed of one-bit quantizers. Then, based on this designed noise-boosted quantizer unit (NBQU), we propose an efficient one-bit multiple signal classification (MUSIC) method for estimating the DOA. Benefiting from the injected noise, the numerical results show that the proposed NBQU-based MUSIC method outperforms existing one-bit MUSIC methods in terms of estimation accuracy and resolution. Furthermore, with the optimal root mean square (RMS) of the injected noise, the estimation accuracy of the proposed method for estimating DOA can approach that of the MUSIC method based on the complete analog data. [ABSTRACT FROM AUTHOR]

Massive multiple input multiple output (MIMO) technology stands as a cornerstone in the evolution of 5G networks. Using an abundance of degrees of freedom, MIMO systems exploit complex spatial characteristics to improve performance. Despite its potential, designing effective 5G MIMO communication systems faces major challenges, primarily in system modeling and channel estimation. Dynamic and complex propagation environments present significant obstacles in accurately representing system behaviour and estimating channel parameters. In order to estimate the channel in the wireless network an improved deep learning based Residual recurrent neural network (ResRNN) is implemented in this paper. Firstly, the least square estimator is used to estimate or calculate the historic channel responses of a pilot block. With these collective responses of the channel, we train the responses using the new deep learning based ResRNN, in which the weight of channel parameters are selected optimally using Improved pelican optimization algorithm (IPOA). Using the IPOA-based ResRNN hybrid precoder the present channel responses can be evaluated or estimated. By varying the length of pilot sequence and by varying the size of antennas at the transmitter and receiver, the metrics such as the bit error rate (BER), mean square error and throughput for (signal to noise ratio) SNR are evaluated. Simulation results show the developed method outperforms the conventional methods by attaining a BER of 10–5 with SNR is 30 dB wireless channel access. The performance of the proposed IPOA-DERNN method is compared with the conventional channel estimation methods. [ABSTRACT FROM AUTHOR]

Orthogonal frequency-division multiplexing (OFDM) is a crucial modulation method used in contemporary digital communication systems for its significant spectral efficiency, low latency, and robustness in challenging environments. This work examines the novel use of OFDM in quantum communication, an area that offers exceptional security and efficiency in information transfer using quantum mechanics principles. In the rapidly evolving field of quantum computing, understanding, and mitigating quantum bit errors is paramount. This paper presents a rigorous analysis of bit error rates (BER) in quantum circuits, focusing on the impact of the quantum Fourier transform and its inverse, contrasted against quantum circuits employing dynamic gate sequences. Our research methodology encompasses simulations over a diverse set of parameters, including varying qubit counts ranging from 2 to 8 and theta angles (15, 30, 45, and 60°), as well as random theta values, utilizing the advanced capabilities of the Qiskit framework. Our findings indicate that quantum OFDM substantially improves quantum communication, lowering errors and boosting security. The quantum model outperforms the reference model in BER, with further enhancements as qubits increase. [ABSTRACT FROM AUTHOR]

When the COMS camera of optical camera communication (OCC) system acquired the information image, the grayscale value of pixels fluctuated due to the influence of blooming effect and light noise, so that the data logic could not be correctly judged by the decision threshold, which affected the bit error rate (BER) performance transmission distance and data rate, and degraded the system performance. In this paper, the adaptive exponential weighted moving average algorithm is proposed, and the optimal grayscale value matrix of signal demodulation is verified by experiment, so as to reduce the fluctuation of grayscale value and improve the performance of OCC system. The experimental results show that for data processing and analysis based on ZYNQ7020 experimental platform, a 7% forward error correction（BER = 3.8 × 10−3）requirements can be satisfied at 150 cm when the data rate is 3 Kbps, and a 7% forward error correction（BER = 3.8 × 10−3）requirements can be satisfied at 100 cm when the data rate is 5 Kbps. [ABSTRACT FROM AUTHOR]

We present a novel photon-acid diffusion method to integrate polymer microlenses (MLs) on a four-channel, high-speed photo-receiver consisting of normal-incidence germanium (Ge) p-i-n photodiodes (PDs) fabricated on a 200 mm Si substrate. For a 29 µm diameter PD capped with a 54 µm diameter ML, its dark current, responsivity, 3 dB bandwidth (BW), and effective aperture size at −3 V bias and 850 nm wavelength are measured to be 138 nA, 0.6 A/W, 21.4 GHz, and 54 µm, respectively. The enlarged aperture size significantly decouples the tradeoff between aperture size and BW and enhances the optical fiber misalignment tolerance from ±5 µm to ±15 µm to ease the module packaging precision. The sensitivity of the photo-receiver is measured to be −9.2 dBm at 25.78 Gb/s with a bit error rate of 10−12 using non-return-to-zero (NRZ) transmission. Reliability tests are performed, and the results show that the fabricated Ge PDs integrated with polymer MLs pass the GR-468 reliability assurance standard. The demonstrated photo-receiver, a first of its kind to the best of our knowledge, features decent performance, high yield, high throughput, low cost, and compatibility with complementary metal-oxide-semiconductor (CMOS) fabrication processes, and may be further applied to 400 Gb/s pulse-amplitude modulation four-level (PAM4) communication. [ABSTRACT FROM AUTHOR]

In order to tackle the problem of reducing the transmission delay of multi-data acquisition source nodes in wireless sensor networks, we propose a cooperative method based on decode-and-forward (DF) and physical-layer network coding. In this proposed method, the two source nodes simultaneously transmit the respective information to the relay node and the data sink node using the orthogonal carriers. The relay node demodulates the received information separately from two source nodes and employs quadrature phase shift keying to modulate these information before forwarding them. The data sink node decodes the information of two source nodes using log likelihood ratio based on the signals received from the direct link and the relay link. Simulation results of bit error rate and system throughput show that the cooperative method can effectively improve the performance of the cooperative system compared with the traditional DF. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive analysis of free space optical (FSO) communication that incorporates the orthogonal frequency division modulation (OFDM) system with differential quadrature phase shift keying (DQPSK) modulation scheme. FSO has become a significant area of research in the optical communication field due to efficient communication systems with higher data transmission rates and lower energy requirements. While transmitting signals through free space, the efficiency of the system is constantly compromised by atmospheric turbulence. In this research, the Gamma-Gamma fading model is considered to incorporate atmospheric turbulence which offers better protection against signal fading and scintillation. Convolutional coding is introduced as the forward error correction (FEC) code with the OFDM technique to ensure better and easier encoding of the signal. The system performance is evaluated in terms of bit error rate (BER). All complex calculations and final result are computed with the help of a hyper-geometrical function, Meijer G. Final results are obtained in graphical form with the help of MATLAB software. System performance is analyzed in terms of BER by varying different system's parameters including the number of OFDM sub-carrier and link distance. Significant amount of coding gain almost 32 dB was found at a BER of 10–9, when the system link length is 2000 m and the refractive index structure parameter is 10–14 m−2/3. [ABSTRACT FROM AUTHOR]

Multiple-input multiple-output (MIMO) technologies use multiple antennas at the sender and the receiver to get the high data rate that the next-generation communication system needs. This paper compares MIMO systems using the Quadrature Phase Shift Keying (QPSK) modulation scheme for two-channel distributions of Rayleigh and Weibull types. The performance of the work is far with the Minimum Mean Square Equalizer (MMSE) in terms of Bit Error Rate (BER) for various antenna number situations on the transmitter and receiver sides. The MIMO module is carried out using MATLAB code. The channel noise will be a signal of random noise that is generated. To mitigate the impact of interchannel interference, the MMSE approach employs inverse filtering at the receiver, and BER will be calculated. According to simulation results, the system's performance is primarily influenced by the number of antennas; it decreased as the number of antennas increased, and the BER of the Weibull channel decreased as the two-parameter value increased. [ABSTRACT FROM AUTHOR]

Mode division multiplexing (MDM) is very competent next generation multiplexing technique and is becoming popular among researchers these days. In this research article, an integrated passive optical network (PON) using MDM and wavelength division multiplexing (WDM) is proposed at 25 Gbps over 3 km multimode fiber (MMF) link distance. For MDM, diverse Laguerre–Gaussian (LG) such as LG12, LG15, LG18, LG111 and LG114 are incorporated and also for cost reduction, vertical cavity surface emitting laser (VCSEL) is located in optical line terminal (OLT). Performance of diverse advanced modulations such as compressed spectrum return to zero (CSRZ), duo-binary return to zero (DRZ) and modified duo-binary return to zero (MDRZ) is evaluated and compared with non-return to zero (NRZ) in terms of Bit error rate (BER) at varied MMF link lengths. Results revealed that CSRZ performance stand out and NRZ provide worst performance. [ABSTRACT FROM AUTHOR]

Free space optical communication is a potential technology that exploits the visible light frequency band for communication. In this paper, a free-space optical link (FSOL) optimization in visible light communication (VLC) is used to improve the channel performance for signal strength and analyze the effect of signal failures in a communication system. The data transmission and reception phenomenon are established using a light-emitting diode (LED) as a carrier at transmitter and photodiode as a detector at the receiver, respectively. The OptiSystem tool uses to optimize the component parameters of this proposed communication system. The bit error rate (BER) analyzer displays the signals as an eye diagram with the challenges of components uncertainty for better signal performance. The optimized components solve the problem encountered transmitting improve and enhance the signals strength. The acceptable eye diagram displayed from the BER analyzer has been resolved as a result of component optimizations by adding and removing noise to ascertain the behavior of the channel. A better signal retrieve by the display of the acceptable eye diagram from the OptiSystem software used. The FSOL components optimization improve the loss of data, weak signal, loss of power, signal failure, and signal errors which guarantee multi-mobile users with the shared signal. OptiSystem software package used to fully characterize the FSOL system. [ABSTRACT FROM AUTHOR]

Optical packet switching has gained lot of momentum in last decade due to the advantages of optical fiber over copper cables. Optical switching is beneficial in optical networks which form connections of links and switching nodes. In these high speed networks minimum delay and high throughput are two important parameters which are considered. To minimize network delay shortest path algorithm is used for route selections. In previous studies while choosing shortest path distance among various nodes is considered. In this work we have shown that it is necessary to consider both distance and number of hops while choosing path from source to destination to minimize power per bit used for the transmission. [ABSTRACT FROM AUTHOR]

To meet the rigorous demands for reliability and spectral efficiency (SE) in the beyond-5th generation mobile network (5G) and the upcoming 6th generation mobile network (6G), a merging codebook based codeword position index modulation scheme for sparse code multiple access (SCMA) is proposed for the uplink SCMA. The scheme expands the codeword position in the time domain, allowing the codeword positions to be fully populated and carry additional information bits by their index, and provides flexibility in adjusting the system SE by changing the codeword position number and the index modulation order. Furthermore, a corresponding joint detection algorithm based on message passing algorithm (MPA) is designed and the design criteria of the merging codebook are given. System analysis and simulation results show that compared with other index modulation schemes, the proposed scheme better balances reliability and SE, and also has advantages in bit error rate (BER) performance and robustness. [ABSTRACT FROM AUTHOR]

In this paper, a novel ultraviolet (UV) scatter communication scheme is presented, designed to dynamically adjust the signal duty cycle to optimize on–off keying (OOK) modulation and reduce the bit error rate (BER), particularly under varying rate settings. This approach addresses the significant challenge posed by LED tailing effects, which cause signal fluctuations and increase BER in high-speed communications. This BER suppression scheme is proposed for the first time in UV communication research, enhancing communication performance without the need for additional hardware or complex algorithms. A UV communication model that incorporates both path loss and LED tailing effects is introduced, with the probability density function of the signal from transmitter to receiver derived. By varying the signal duty cycle, tailing-induced BER is effectively minimized. Additionally, a closed-form expression for signal transmission BER using a single-scattering model is provided, and the proposed UV communication system is validated through comprehensive simulations and experimental tests. The results indicate that LED tailing has a pronounced impact on BER at higher communication speeds, while its effects are less significant at lower speeds. By optimizing the duty cycle parameters for various communication rates, findings demonstrate that lower duty cycle settings significantly reduce the BER at higher speeds. This further demonstrates the excellent performance of the proposed UV communication solution for OOK-modulated optical communication. [ABSTRACT FROM AUTHOR]

In order to meet the increasing requirements of speed and distance, an advanced digital signal processing (DSP) algorithm is preferred without changing the system structure in intensity modulation and the direct detection (IM/DD) system. As the transmission distance increases, the power fading induced by dispersion must be mitigated. In addition, linear and nonlinear inter symbol interference (ISI) introduced by bandwidth limitation and device imperfections becomes an obstacle to achieving higher capacity. The Gerchberg–Saxton (GS) algorithm was recently used to compensate for dispersion. In this paper, GS-based pre- and post-compensation schemes in the IM/DD system with nonlinearity were investigated. We investigated and compared the performance of the GS-based pre- and post-compensation algorithm in a 28 GB aud four-level pulse amplitude modulation (PAM-4) transmission over 40 km standard single-mode fiber (SSMF). The bit error rate (BER) achieved a threshold of 3.8 × 10−3 using look-up-table (LUT), FFE, and the GS-based pre-compensation algorithm without iterations. Turning to the GS-based post-compensation scheme, 80 iterations are needed. However, the demand for FFE is reduced. The algorithm selection depends on the tolerance of the transmitter or receiver complexity in specific scenarios. The joint LUT and GS-based pre-compensation algorithm may be a preferable approach in scenarios where a low-complexity receiver is desired. [ABSTRACT FROM AUTHOR]

This paper presents an analytical study of signal clipping that leads to the noise/distortion in the waveform of DC-biased optical orthogonal frequency division multiplexing (DCO-OFDM)-based visible light communication (VLC) systems. The pilot-assisted (PA) technique is used to reduce the high peak-to-average power ratio (PAPR) of the time-domain waveform of the DCO-OFDM system. The bit error rate (BER) performance of the PA DCO-OFDM system is investigated analytically at three different clipping levels as well as without any clipping. The analytical BER performance is verified through simulation and then compared to that of the conventional DCO-OFDM without PAPR reduction at the selected clipping levels. The PA DCO-OFDM system shows improved BER performance at all three clipping levels. [ABSTRACT FROM AUTHOR]

We propose a novel reception scheme for twin single-sideband (twin-SSB) signals using just a single photodetector (PD), significantly reducing the system complexity and cost. To detect a twin-SSB with power-unbalanced quadrature-phase shift keying (QPSK) sidebands upon detection via a single PD at the receiver side, two QPSKs carried in two sidebands are coherently superposed and detected in a 16-ary quadrature amplitude modulation (16-QAM) format. This technique notably diminishes the linearity and effective number of bits required for the transmitter components in high-speed optical transmission systems. Moreover, a hierarchical blind-phase search (HBPS) algorithm is proposed to compensate for the imperfect phase rotation of QPSK signals during transmission. To demonstrate the effectiveness of our proposed method, we successfully conducted simulations of 112 Gb/s 16-QAM signal transmission over a 10 km standard single-mode fiber (SSMF), achieving bit error ratios (BERs) of 7.84 × 10 − 4 , well below the 7% hard-decision forward error correction (HD-FEC) threshold of 3.8 × 10 − 3 . In addition, the synthetic transmission scheme proposed in this paper is compared with the traditional 16-QAM signal transmission scheme, and the results show that the proposed scheme does not introduce a performance cost with the same received optical power (ROP) and transmission distance. [ABSTRACT FROM AUTHOR]

In order to further improve the transmission and spectral efficiency of the MC-DCSK system, a novel security system called Joint Mapping Multi-Carrier Differential Chaos Shift Keying (JM-MC-DCSK) is proposed in this paper. A novel joint mapping scheme is designed which consists of two parts: matrix reshaping mapping and combination mapping. Moreover, in order to correctly demodulate the information bits in the index obtained through Maximum Likelihood Estimation (MLE), we propose a new index mapping algorithm to match this joint mapping scheme. The information bits are first mapped into U mutually orthogonal matrices in the matrix reshaping mapping structure. In this structure, we employ segmental shifts of the orthogonal submatrices instead of cyclic shifts to eliminate intra-signal interference, which contributes to the reliability of the system. Then, in the combination mapping structure, the information bits are modulated by N orthogonal carriers after being replicated U times. In each carrier signal, we arbitrarily select two sequences from the U orthogonal chaotic sequences to be superimposed. This scheme can map more information symbols and the randomness of the combination selection provides more flexibility for the mapping algorithm. The Bit Error Rate is derived and analyzed under Additive White Gaussian Noise and Rayleigh Fading Channel by Gaussian approximation method and central limit theorem, and numerical simulations are conducted to verify the correctness of theory. Additionally, the simulation results demonstrate that the system also has lower BER and Peak-to-Average Power Ratio, reflecting its significant theoretical and practical engineering value. [ABSTRACT FROM AUTHOR]

In the future, intelligent transportation systems will rely heavily on vehicle to vehicle (V2V) communication-based cooperative vehicular networks since they can provide several applications for tackling traffic congestion and road safety. Future 6G and New Radio 5G (NR5G) technology will facilitate improving cellular vehicle to everything (CV2X) communication performance. Cellular-assisted V2V communications, in which cellular evolved Node base stations (eNBs) relay the transmission from one vehicle to another, have lately been proposed to overcome the performance restrictions of conventional dedicated short-range communication (DSRC) protocols (Kimura in IEEE Trans Veh Technol 70(4): 3396–3411, 2021. 10.1109/TVT.2021.3063694). These cellular-aided communications have demonstrated the potential for more reliable V2V communications with a larger capacity and longer transmission distances. In this paper, we theoretically examine the effectiveness of cellular vehicle to everything communications, where a vehicle broadcasts a message to its nearby vehicles or user equipment (UEs). It happens in two ways, i.e., direct vehicle to vehicle and via the closest eNB through an uplink. Then the closest eNB forwards the message to the destination vehicle via downlink i.e., vehicle to network (V2N) or vehicle to infrastructure (V2I). To obtain a suitable model for estimating the Bit Error Rate (BER) and the Packet Error Rate (PER), we consider the movement of three vehicles are in a straight line on the roadways with different velocities. Using numerical examples, we assess the analytical findings and show how different system factors affect the effectiveness of CV2X communications. A simulation has been carried out in the network (system) level context. [ABSTRACT FROM AUTHOR]

In the Multiple Output – Orthogonal Frequency Division Multiplexing (MIMO – OFDM) system, the Fifth Generation (5G) plays an important role due to the extraordinary features and advantages of mobile communication. These 5G works in any aspect of the industry to improve speed because of better capacity, frequency, and lower delay. The existing system Align Crow Search (ACS) algorithms are implemented in the uplink of the MIMO – OFDM system to reduce the Bit Error Rate (BER) from 10−1 to 10−4 . In the uplink, the Inter Symbol Interference(ISI) and Inter-Carrier Interference (ICI) are evolved due to the implementation of OFDM, which deals with the several number of subcarriers transferred. The Binary Subcarrier Search is proposed to detect and reduce the ISI and ICI, with Hilbert Matrix to avoid the Peak to Average Power Ratio (PAPR). Then, the 38 GHz MIMO antenna is implemented through the channel, which can reduce the Bit Error Rate (BER) in the downlink of the system. It provides 80% efficiency with higher gain and the 14 GHz bandwidth with grand parameters of 5G. Finally, the MIMO-OFDM system yields better performance by using BSS – HBM through the 39 GHz antenna with substrate size 3.039 mm x 2.548 mm in the 5G Application. Hence the conventional method ACS is compared with the BSS – HBM to enhance better signal-tonoise ratio (SNR), Lower BER, and reduction of ICI with high efficiency given in the simulated results. [ABSTRACT FROM AUTHOR]

The Narrowband Internet of Things (NB-IoT) technology is considered as an attractive option for IoT applications due to its ability in offering better connectivity in weak coverage areas. However, current research on NB-IoT systems primarily focuses on improving its distribution network, while neglecting the importance of channel condition estimation. To overcome these shortcomings, this article proposes a joint channel coding as well as channel estimation approach that aims to enhance the reliability and efficiency of data transmission over wireless channels. The proposed concatenation technique incorporates both polar coded data transfer and channel estimation procedures, which increases the system's reliability and efficiency even under immoral radio coverage conditions. The system utilizes the crossover boosted sooty tern optimization (CBSTO) based polar coding algorithm to design polar code parameters, resulting in improved error correction performance. Additionally, DNN-based linear minimum mean square error (LMMSE) channel estimations are performed at receiver side to ensure accurate channel equalization and decoding of received data bits. The simulation experiment conducted to validate the proposed NB-IoT system demonstrates its improved error correction performance and high throughput compared to other methods. The proposed scheme could help enhance the efficiency and reliability of NB-IoT systems, particularly in weak coverage areas. This paper highlights the importance of considering channel condition estimation in the development of NB-IoT systems, which could have significant implications for the future of IoT applications. [ABSTRACT FROM AUTHOR]

Abstract The integration of large intelligent surfaces (LIS) with non-orthogonal multiple access (NOMA) networks has emerged as a promising solution to enhance the capacity and coverage of wireless communication systems. In this study, we analyse the performance of a NOMA network with the assistance of LIS. We propose a system model where a base station (BS) equipped with a LIS serves multiple users. The LIS consists of many passive elements that can influence the wireless channel by adjusting the reflection coefficients. We consider a downlink scenario where the BS transmits to multiple users simultaneously using NOMA, and the LIS helps to improve the signal quality and coverage. We additionally evaluate the efficiency of the suggested LIS-assisted NOMA network. In addition, we evaluate the efficiency of the LIS-assisted NOMA network in comparison to conventional NOMA systems that do not utilize LISs. The findings indicate that the LIS has a notable impact on enhancing the system's performance in terms of diversity gain, probability of error, and pairwise error probability (PEP). Moreover, the suggested LIS-assisted NOMA network is shown to be superior to conventional NOMA systems through comparison. These findings offer useful insights into the performance analysis of LIS-assisted NOMA networks. They also serve as inspiration and motivation for future research and development in this new subject, with the potential to revolutionize wireless communication systems.