Bit Error Rate (BER)

While we benefit from the capabilities of Denoising Auto-Encoders (DAEs), some security
risks also arise with the widespread adoption of these systems. Conventional chaos masking and jamming
defenses do not protect against DAE-equipped eavesdroppers. Chaotic masking adds randomness to signals
and helps with security, but it cannot stop detection by a DAE. To tackle this problem, we design a secure
Brain-Computer Interface (BCI) using Long Short-Term Memories (LSTMs) that combines adversarial
training and chaotic signals. We formulate an optimization problem to model the proposed BCI and generate
a low-power perturbation vector. The results indicate that when the noise variance is equal to 0.2, the
Root Mean Square Error (RMSE) of an illegal DAE exceeds 1.2. At the same time, the non-adversarial
performance is approximately 0.5. Moreover, the performances of different Neural Networks are evaluated
under the same computational complexity conditions. The best result is provided by the LSTM, with a
complexity of about 3 × 104 Real Multiplications per Symbol (RMpS). The proposed Adversarial Chaos
Synergy (ACS) framework is compatible with cloud/edge infrastructure. With these features, the ACS
approach is suitable for applications such as mobile medical services, lightweight bio-medical instruments,
brain-to-brain networks, and smart hospitals.

In this paper, we propose a feedback-efficient hybrid precoding framework for wideband millimeter-wave (mmWave) multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems. To mitigate the high cost of radio frequency (RF) chains and channel state information (CSI) feedback in large-scale antenna arrays, we first construct frequency-flat analog precoders by extracting dominant angle-of-arrival (AoA) and angle-of-departure (AoD) directions from sparse frequency-domain channels. For digital precoding, we design a quantized codebook using the Lloyd algorithm and develop a binary-search-based hierarchical interpolation algorithm that adaptively assigns codewords according to subcarrier correlation. The proposed method achieves sublinear feedback scaling by reducing the feedback overhead from O(K) to O(K/M +log M), where K is the number of subcarriers and M is the pilot spacing. Simulation results demonstrate that the proposed method achieves comparable or superior spectral efficiency and bit error rate (BER) performance to existing clustering and interpolation schemes, while significantly reducing computational complexity and exhibiting robustness under imperfect CSI.

Underwater Wireless Communication (UWC) systems play a crucial role in marine exploration, oceanographic research, and autonomous underwater vehicle (AUV) navigation. This paper presents a simulation-based analysis of a cost-effective underwater communication model utilizing ultrasonic transducers. The proposed system employs a transmitter-receiver pair to enable data exchange through a water medium, where ultrasonic pulses serve as the carrier signals. Key performance metrics such as signal attenuation, signal-tonoise ratio (SNR), and bit error rate (BER) are evaluated through MATLAB simulations and acoustic propagation models. The results demonstrate that ultrasonic communication provides reliable short-range data transmission up to 10 meters, highlighting its potential for integration into future Internet of Underwater Things (IoUT) applications.

The estimation of the probability of bit error in digital communication systems has received considerable attention over the years. It is not only a measure of the performance of the communication system but also an invaluable feedback parameter for systems using adaptive control strategies. An optimal method for estimating this parameter in real-time for uncoded modulation has been devised and this paper significantly extends that work by estimating bit error probability of communication systems employing error-control coding. We show by analysis and simulation that the performance of the new estimator approaches the minimum variance bound and we contrast this with the performance of alternative techniques.

MIMO-OFDM (multiple inputs and multiple output orthogonal frequency division multiplexing) system is a new wireless broadband technology which has gain great popularity for its capability of high rate transmission and its strength against multipath fading. In this paper turbo coding, Zero Forcing and Minimum Mean Square Error equalization techniques are presented for reduction in bit error rate for the 16QAM modulation technique. The channel used in this paper is Rayleigh frequency selective channel.

- TCP is a dominant protocol for consistent communication over the internet. It provides flow, congestion and error control mechanisms while using wired reliable networks. Its congestion control mechanism is not suitable for wireless links where data corruption and its lost rate ...

This study explores Skew Variation in 192-cell BMS configurations. Such systems face challenges in maintaining noise-resilient communication across modules. The Controller Area Network with Flexible Data Rate (CAN FD) and daisy-chained Serial Peripheral Interface (SPI) are benchmarked over 5-meter interconnects This paper presents a novel side-by-side analysis of CAN FD and SPI under identical physical conditions in a 192-cell topology, providing quantitative guidance for real-world BMS protocol selection. Protocol behaviors were validated using a dSPACE-based Hardware-in-the-Loop (HIL) setup under fault injection scenarios. CAN FD demonstrates 3x lower BER than SPI at 5 meters. Skew variation in SPI reaches 12 ns versus 4 ns in CAN FD. CAN FD retains 85% of differential margin beyond 4 meters. SPI maintained better latency, with 1.2 ms vs. 1.5 ms for CAN FD. Consider explaining why it's favored: ...due to its simplicity and tight coupling with internal BMS logic. BMS ICs from Texas Instruments and Analog Devices guided protocol integration design. Findings recommend protocol selection based on trade-offs among noise tolerance, communication latency, and wiring architecture. This work distinctively compares both under identical physical constraints. Previous studies have not comprehensively analyzed such long-chain configurations under identical conditions. Results indicate CAN FD offers robust performance in longer, modular topologies. This paper provides comparative, simulation-based design guidance for selecting communication protocols in long-chain, modular BMS configurations.

A model of Turbo code based on OFDM (Orthogonal Frequency Division Multiplexing) is proposed in this paper. Orthogonal Frequency Division Multiplexing (OFDM) has become a popular modulation method in high speed wireless communications. By partitioning a wideband fading channel into flat narrowband channels, OFDM is able to mitigate the detrimental effects of multipath fading using a simple one-tap equalizer. There is a growing need to quickly transmit information wirelessly and accurately. OFDM is a suitable candidate for high data rate transmission with forward error correction (FEC) methods over wireless channels. In this project the system throughput of a working OFDM system has been enhanced by adding turbo coding. The use of turbo coding and power allocation in OFDM is useful to the desired performance at higher data rates. Simulation is to be done over additive white Gaussian noise (AWGN) and impulsive noise (which is produced in broadband transmission) channels. The wideband ...

Ultra dense network (UDN) and reconfigurable intelligent surface (RIS) are two latest technologies in encountering the increasing demands for network capacity and quality of service in wireless cellular networks. UDN is created by densely deploying femtocells in macrocells area. It causes complex interferences because distances among femtocells are likely very close. RIS provides solution in regulating the reflection of the signal emitted from the transmitter to the receiver to resolve the obstacles. However, RIS reflects the interference signals as well causing more complex interference problems. This paper proposes a solution using clustering method as interference management in RIS-aided UDN network. By clustering method, nearby femtocells are grouped and allocated different frequency channels among femtocells in a cluster. The performance of two systems-the baseline system and the one employing a clustering method-is evaluated based on signal to interference plus noise ratio (SINR), throughput, and bit error rate (BER). Simulation results indicate that SINR and throughput improved by 1.57% and 1.73%, respectively. Meanwhile, the BER for the baseline system is 5.78×10-8 and decreased when applying the proposed method system with a value of 2.26×10-8. The proposed clustering method is promising to confront the interference problems.

Modern communication systems adopt the principle of wireless communication as a basic choice in life in the city and nearby offices. Systems are often expensive and monopolized by governments and
regimes, so many researchers around the world are interested in finding systems that can be of a cheap nature, have good communication quality, and can send data at an acceptable to excellent rate. Free space optical system is one of those systems that unlicensed and cost-effective system. In this study we found the optimum wavelength for FSO system and apply it with the three main weather condition fog, rain and snow. FSO using many techniques like a LOS (line of sight) and multibeam sending data where voice, video communication and data is achieved with high data rate by bidirectional full duplex connectivity[1].
The 850 nm wavelength is very suitable for FSO system because of it’s reliable, high-performance, and inexpensive transmitter and detector components. Also, they are generally available and commonly used in today’s service provider networks and transmission equipment[6].

The modern applications of communications that use wideband signals suffer the lacking since the resources of this kind of signals are limited especially for fifth generation (5G). The Compressive Spectrum Sensing (COMPSS) techniques address such issues to reuse the detected signals in the networks and applications of 5G. However, the raw techniques of COMPSS have low compression ratio and high computational complexity rather than high level of noise variance. In this paper, a hybrid COMPSS scheme has been developed for both non-cooperative and cooperative cognitive radio networks. The proposed scheme compiles on discrete wavelet transform – single resolution (DWT-SR) cascaded with discrete cosine transform (DCT). The first is constructed according to the pyramid algorithm to achieve 50% while the second performed 30% compression ratios. The simulation and analytic results reveal the significant detection performance of the proposed technique is better than that of the raw COMPSS te...

Free Space Optics (FSO) is a wireless optical communication system using light to establish high-capacity links between points without the need for physical cables. However, its susceptibility to atmospheric conditions such as fog, rain, and turbulence presents challenges to signal quality maintenance. To address this, Dense Wavelength Division Multiplexing (DWDM), traditionally employed in fiber optics, is leveraged to optimize bandwidth utilization and scalability in high-capacity communications. The integration of DWDM into FSO systems offers redundancy and resilience against signal degradation induced by atmospheric conditions. To the best of our knowledge, this is the first time a paper explores the performance of the Subcarrier Index Modulation Orthogonal Frequency Division Multiplexing (SIM-OFDM) technique within a DWDM-FSO system. The objective is to reinforce FSO link robustness and improve transmission rates. Through a comparative analysis with conventional OFDM in an Additive White Gaussian Noise (AWGN) channel, the study reveals a notable Signal-to-Noise Ratio (SNR) gain of at least 3dB with enhanced SIM-OFDM (ESIM-OFDM). Simulations, conducted with realistic parameters within the DWDM-FSO architecture, demonstrate that ESIM-OFDM modulation enables a transmission range of 2 km with an aggregated rate of 10.1 Gb/s. These results underscore the potential of SIM-OFDM in enhancing FSO system performance through the integration of DWDM technology. The proposed ESIM-OFDM DWDM-FSO scenario could represent a highly interesting solution for establishing 5G Backhaul links.

WiMAX OFDM-based systems are characterized by their ability to provide high data rate with low BER (bit error rate) at low SNR (signal to noise ratio). In this paper, we demonstrate the performance of the system under real fading IEEE standardized channels; originally known as the Stanford University Interim (SUI) channels for broadband wireless access. The six channel models characterize most possible environmental fading effects. They define three terrain channel types; soft fading environment (SUI 1 and SUI 2), intermediate fading environment (SUI 3 and SUI 4) and harsh fading environment (SUI 5 and SUI 6). Each fading environment is thus characterized by two channels representing the possible extremes so that the actual fading channel falls in between. All mandatory WiMAX parameters such as BPSK, 16-QAM, Reed Solomon encoding, to name a few, were used in the simulation of the system and their results in terms of BER versus SNR plots were analyzed. Our focus is on optional parame...

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

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