High-speed Communication Research Articles

A Review on Deployment of UAV-FSO System for High-Speed Communication

A Review on Deployment of UAV-FSO System for High-Speed Communication

CRaTeBo: a high-speed, radiation-tolerant and versatile testing platform for FPGA radiation qualification for high-energy particle accelerator applications

The CHARM Radiation Tolerant FPGA Tester Board (CRaTeBo) is a FPGA testing platform for the CERN High-energy Accelerator (CHARM) irradiation facility. It is meant to ease the radiation testing of FPGA-based systems by providing users with a radiation-tolerant carrier card featuring an FPGA interface, a high-speed communication interface, a flexible power supply, and an HPC-FMC connector for additional front-end electronics. It is foreseen to be a permanent installation in the CHARM facility at CERN, giving users the possibility to carry out radiation tests of their system with minimum effort on the test setup development.

Research on high-speed communication mechanism of time-triggered network based on RGMII

Research on high-speed communication mechanism of time-triggered network based on RGMII

Method for the Simultaneous Generation of Two Nonlinear Pseudo Random Sequences: 5-ary and Binary

Multi-level signals and sequences have become a significant aspect of modern high-speed communication systems. Hence, to ensure the confidentiality and integrity of the transmitted information, advanced methods and devices are necessary to produce strong cryptographic properties for not only binary but also for nonbinary keystreams, which can be used in resource-constrained microcontrollers. The proposed method and apparatus generate both a balanced nonlinear 5-ary pseudo-random sequence and a binary keystream sequence. The nonlinearity is determined by applying shrinking and multiplexing techniques to the generated linear 5-ary pseudo-random sequence and the running zero in its conversion to a binary balanced sequence.

High-Efficiency Multi-Channel Orbital Angular Momentum Multiplexing Enabled by the Angle-Dispersive Metasurface.

Orbital angular momentum (OAM) multiplexing of electromagnetic (EM) waves is of great significance for high-speed wireless communication and remote sensing. To achieve high-efficiency OAM multiplexing for multi-channel incident EM waves, this paper presents a novel angle-dispersive meta-atom structure, which can introduce the required anti-symmetric phase dispersion as well as high transmission efficiency for OAM multiplexing. These meta-atoms are then arranged delicately to form an angle-dispersive metasurface working at the X band, which enables three-channel OAM multiplexing by converting highly directional transverse-magnetic (TM) waves incident from 0 and ±45° to coaxial OAM beams with l = 0 and ±2 modes, respectively. The simulation and experimental results reveal that the proposed metasurface can convert a higher proportion of energy to the required OAM modes compared to the conventional OAM multiplexing metasurfaces, which can significantly improve the coaxial transmission efficiency of multi-channel OAM multiplexing.

Conditional Most-Correlated Distribution-Based Load-Balancing Scheme for Hybrid LiFi/WiGig Network.

A hybrid network has recently been proposed as a framework for a high-speed wireless communication network. Basically, it integrates light fidelity (LiFi) with radio frequency wireless gigabit alliance (WiGig) networks that operate, simultaneously, in a completely different frequency band. To assign the best access point (AP) and provide enough resources for each user, an effective load-balancing (LB) strategy is needed. However, the traditional LB strategies involve sophisticated iterative computing procedures whenever the user distribution changes. Hence, the first contribution of this work is to offer a more adaptable, two-step, conditional, and most-correlated distribution (CMCD) algorithm. Thus, the low-complexity most-correlated distribution (MCD) LB scheme is applied, and the average data rates for all users are then calculated. If the results achieve the predefined performance threshold (PDT), the decisions will be confirmed; otherwise, the proposed scheme automatically switches to the more accurate, but more complex, consecutive assign WiGig first separate optimization algorithms (CAWFS) algorithm. The suggested algorithm provides a clear performance-complexity trade-off, which could be simply controlled by choosing the suitable performance tolerance factor. The second contribution of this paper is the correlation-weighted majority voting (CWMV) method, which attempts to benefit from as many prior decision votes as possible, instead of relying just on one vote. In the CWMV technique, the weight of each vote is calculated based on the correlation between the history distribution vectors and the new user distribution vector. A significant increase in the system performance is evident from the simulation results.

Characterization and Validation of PAM4 Signaling in Modern Hardware Designs

To satisfy rising data capacity and bandwidth demands, Pulse Amplitude Modulation with 4 levels (PAM4) has become a popular signaling system in high-speed digital communication. As contemporary hardware designs restrict Non-Return-to-Zero (NRZ) signaling, PAM4 offers an appealing alternative by doubling data flow within the same bandwidth. Using PAM4 signaling provides distinct characterisation and validation problems that must be addressed to assure dependable performance in modern hardware systems. Modern hardware designs' PAM4 signaling characterisation and validation are covered in this research report. PAM4 signaling fundamentals, including modulation technique, signal integrity, and high-speed data transfer, are examined in the research. PAM4's higher data rates and spectrum efficiency are highlighted in the article, along with its implementation issues. Much of the study characterizes PAM4 signaling. This involves developing reliable signal measuring methods, analyzing signal loss owing to ISI and jitter, and assessing PAM4 performance based on hardware components. PAM4 signal behavior under diverse settings is characterized using advanced methods as eye diagram analysis, constellation diagram evaluation, and error vector magnitude (EVM) measurement. The paper tests and simulates PAM4 signaling to validate it. A thorough approach for testing PAM4 performance in lab and real-world conditions is provided. PAM4 signaling resilience in different hardware contexts is tested using specialist test equipment and simulation tools. The validation method includes BER, SNR, and industry standard compliance.The study also examines how new hardware design affects PAM4 signaling. Advanced circuit design, packaging, and material qualities affect signal integrity and performance. High-speed data interface designers and engineers may learn from the paper's ideas for reducing signal degradation and improving PAM4 signaling in complicated hardware systems.

Designing an active electronically scanned array as part of onboard equipment of a high-speed radio communication channel

The active electronically scanned array being developed is designed to provide an all-weather high-speed radio communication channel “Spacecraft – Earth”. It is supposed to provide fast, inertia-free observation of space by swinging the antenna beam electrically, and, in fact, is a dynamic space-time filter of the spacecraft. The aim of the work is to identify the basic principles of functioning of the array as part of the spacecraft with inherent limitations in the mass-dimensional and energy characteristics of the onboard equipment and, at the same time, high requirements for the functional characteristics. This paper presents the calculation and the main results of designing an active electronically scanned array complying with the requirements for optimizing the parameters of the antenna system. To assess the effect of scanning on the phase characteristics of the chips, a nonlinear amplifier model was developed. A statistical analysis of the phase characteristics was carried out when the load resistance changed in accordance with the obtained distribution laws. When calculating the resulting directional pattern of the antenna array, destabilizing factors were taken into account in accordance with the results of the study of the prototypes of the antenna array being created. Phase errors were calculated, mainly determined by the errors of the terminal parts of the receiving paths. Measures were implemented to ensure the effect of such phase errors on the directional pattern of the array only on the far side lobes.

Separation and detection of orbital angular momentum states of composite vortex beams in atmospheric turbulence channels

The separation and detection of compound orbital angular momentum (OAM) modes are the basis for achieving high-speed and high-capacity communication, but the atmospheric turbulence causes distortion of the phase fronts of vortex beams, which hinders the recognition of OAM modes. To solve this problem, in this work, we propose and investigate a joint scheme of combining the Gerchberg–Saxton (GS) algorithm and the phase of addition and subtraction model that can achieve high recognition accuracy and a wide range of OAM modes of compound perfect optical vortex beam under long-distance turbulence environment. At the receiving end, the GS algorithm and phase addition and subtraction are used to compensate and modulate the incident vortex light field to obtain the pre-processed light field, and then the OAM is detected by the coordinate transformation method. The simulation results show that: The detection range of the OAM of the three optical path detection model for the vortex beam transmitting 1000 m reaches −37 to +37 in the vacuum environment, and the mode purity of −37 to +37 can reach more than 0.3 when the turbulence intensity is Cn 2 = 2 × 10−15 m−2/3. The detection range of the OAM of the vortex can be further expanded by increasing the optical path. This study provides a new method for the separation and detection of OAM of composite vortex beams.

O-Shape Fractal Antenna Optimized Design with Broad Bandwidth and High Gain for 6G Mobile Communication Devices

Optimization of antenna parameters is important for achieving the best design that has higher results for gain and bandwidth while also having a smaller size. One such antenna design is numerically investigated and presented in this research. The antenna is optimized to an O-shape fractal design from a square patch design. The antenna is created by etching a slot of a square patch and making an O-shape fractal metamaterial patch antenna that operates on the THz band. The THz patch antenna is also investigated for its metamaterial properties. The optimization of the THz patch antenna is carried out for substrate height, slot length, and slot width. The optimized design has a size of 65 × 65 µm2. The highest bandwidth of 31.4 THz (138%) and the highest gain of 11.1 dBi is achieved. The optimized design is then investigated for multiple elements. The two-element MIMO antenna design using an O-shape patch is investigated to observe its performance and compare it with an O-shape single-element design. The two-element MIMO antenna design gives two bands with a bandwidth of 18 THz (113%) and 21 THz (56%). The gain of this design is 5.18 dBi and the size is 130 × 65 µm2. A comparison between the O-shape single-element fractal design, two-element fractal MIMO design, and other published designs is carried out. The compact, broadband, and high gain design presented can be used for 6G high-speed mobile communication devices.

High-speed physical layer secure communication scheme based on synchronous chaotic and electro-optic self-feedback dual-phase encryption

In this paper, a novel secure communication scheme based on temporal spreading and dual-phase perturbation is proposed to improve security at the physical layer. For one thing, the traditional electro-optical feedback phase encryption system is significantly sophisticated by the introduction of additional synchronized chaotic phase encryption. Besides, more keys in this system are available, with the attendance of dispersion and optical chaos, the key space is notably enhanced to ∼236, resisting the eavesdropping attacks. After passing through a series of encryption devices, the information is ultimately displayed as a noise-like signal. A 32 Gb s−1 on-off keying signal is successfully transmitted over a 100 km standard single-mode fiber. Simulation results show that by selecting the appropriate system parameters, a bit error rate as low as 10−10 can be obtained for legitimate terminals, and the effect of different hardware parameter mismatches on the decryption performance is also investigated which indicates a certain tolerance range for the mismatch of each parameter. This paper provides a new idea to combine an electro-optical feedback system with optical chaos to establish optical secrecy communication.

Designing high-speed GEO-to-Moon optical wireless communication links

Moon exploration and colonization will strongly rely upon high-speed optical wireless communications over a huge distance (around 400,000 km). Here, we introduce a holistic model, including the propagation issues as well as the realistic communication limitations and the expected practical limitations. We focus on the communication issues in a link connecting a GEO satellite to a fixed Moon optical station: here, we consider the challenging 10 Gbit/s transmission rate, and we assume an optical pre-amplified receiver, which is today the only option for high speed; we then select three different modulation formats, with corresponding implementations and increasing complexity and performance. Under these assumptions, we estimate the common operating conditions at the forward error correction threshold and point out the role of the transmitter and receiver telescopes: for practical size (e.g., 1 m), relevant limitations arise, which we combine with the typical photons-per-bit sensitivity values in an optical link. We find that all considered modulation formats can be used at 10 Gbit/s, although with different margins and hardware requirements, particularly considering the size of the optical antennas. We then extend the analysis to higher rates, up to 40 Gbit/s. This work can open the way to the realization of optical wireless communication systems to/from the future Moon Village.

Enhanced bandwidth of a lateral-pin Ge/Si avalanche photodiode using inductive gain peaking

Lateral-pin germanium silicon avalanche photodiodes (APDs) offer great potential for improving performance, cost-effectiveness, and versatile production processes for large-capacity data communication applications. However, excessive avalanche multiplication noise limits the increase in bandwidth. In this study, we propose and design the integrated peaking inductors to enhance the bandwidth of a lateral pin Ge/Si APD without compromising the direct current (DC) characteristics. By introducing the spiral inductor to counteract the capacitive effect of APD, the RF output power at high frequency can be effectively increased, thus improving the photodiode bandwidth. The impact of different sizes of inductors and APDs on the performance was experimentally investigated. The resulting APDs, with Ge lengths of 20μm (Ge20) and 45μm (Ge45), provided low dark currents of 11 nA and 27 nA, and primary responsivities of 0.85 A/W and 1.05 A/W at −1 V, respectively. A small inductor (375 pH) exhibited greater bandwidth enhancement than a large inductor (622 pH) and the Ge20 APD achieved a bandwidth of up to 78 GHz. For the larger Ge45 APD, the bandwidth was maintained above 50 GHz, even close to the breakdown voltage, and a high gain-bandwidth product of up to 609 GHz was calculated by an avalanche multiplication gain of 11.7. This result may provide ideas for balancing the speed and sensitivity of lateral-pin APDs used in high-speed optical communications.

Computer vision-aided mmWave communications for indoor medical healthcare

Comprehensive and exceedingly precise centralized patient monitoring has become essential to advance predictive, preventive, and efficient patient care in contemporary healthcare. Millimeter-wave (mmWave) technology, boasting high-frequency and high-speed wireless communication, holds promise as a viable solution to this challenge. This paper presents a new approach that combines mmWave communication and computer vision (CV) to achieve real-time patient monitoring and data transmission in indoor medical environments. The system comprises a transmitter, a reflective surface, and multiple communication targets, and utilizes the high-frequency, low-latency features of mmWave as well as CV-based target detection and depth estimation for precise localization and reliable data transmission. A machine learning algorithm analyses real-time images captured by an optical camera to identify target distance and direction and establish clear line-of-sight links. The system proactively adapts its transmission power and channel allocation based on the target’s movements, guaranteeing complete coverage, even in potentially obstructive areas. This methodology tackles the escalating demand for high-speed, real-time data processing in modern healthcare, significantly enhancing its delivery.

Dual-Wideband Antenna with Dual Polarization and Enhanced Front-to-Back Ratio for High-Speed Communication Applications

The proposed antenna introduces a dual-wideband, dual-polarization design, employing Y-shaped bowtie radiators strategically positioned on both sides of an FR-4 substrate. This configuration aims to achieve polarization diversity, a crucial aspect in enhancing the performance and efficiency of wireless networks. To achieve this, improvements were made in radiation characteristics, particularly the front-to-back ratio (FBR), through the incorporation of a ring reflector and director. This led to an impressive average FBR enhancement of 7.38 dB at the lower band (LB), and 4.94 dB at the upper band (UB), respectively. Furthermore, the reflector and director height in relation to the radiator was meticulously adjusted to achieve a low-profile structure of dimensions 0.340λ0 × 0.340λ0 × 0.126λ0 (at 0.698 GHz). The antenna features both horizontally and vertically positioned radiators, each fed by two ports. It demonstrates an extensive overlapping impedance bandwidth (IBW) (S11 < -10dB) of 0.68-0.99 GHz (37.8%), and 1.62-2.99 GHz (61.9%) in the LB and UB for both radiators, with port isolation exceeding 18 dB. Alongside dual polarization and an enhanced FBR, the radiator exhibits a gain beyond 4.8 dBi and a radiation efficiency better than 70%, making it an exceptional choice for applications requiring high-speed wireless communication.

Electro-optical modulator based on lithium niobate notched-ring plasmonic metasurface coated with electro-optical polymer

High speed and large capacity optical communication technology requires various optical devices, including optical modulators. Herein, an electro-optical (EO) modulator based on lithium niobate notched-ring plasmonic metasurface (LNPM) coated with EO polymer is demonstrated. The transmission and reflectance characteristics of the LNPM are simulated by finite element method (FEM), and the results show that the LNPM coated with EO polymer has resonant peaks at the operating wavelengths of 1.59 and 1.62 μm for the TM and TE polarized lights, respectively. The parameter optimizations indicate that the resonant peaks of the LNPM move towards higher frequency when the period (P) decreases or the notched-ring diameter (D) increases. The EO modulation performances show that the EO wavelength tuning (EOWT) of the HEOT-LNPM is 90 pm/V, and the maximum modulation depth (MD) is 17.5 dB with an extinction ratio (ER) of 20.2 dB. The LNPM coated with EO polymer provides a feasible EO modulation scheme for the optical communication, optical signal processing, and optical network links. Furthermore, it has promising applications in the fields of 5G communication, cloud computing, internet-of-ting, and artificial intelligence.

Sparse kernel affine projection algorithm based post-distortion scheme using minimum symbol error rate criterion in visible light communication systems

Due to the capability of supporting high-speed data communication with low energy cost, visible light communication has emerged as a promising supplement to radio frequency communications. However, the inherent nonlinearity caused by the light emitting diode could distort the signal, and thus posing a challenging problem for the system performance. In order to mitigate the nonlinear effect, reproducing kernel Hilbert spaces based schemes are recently investigated, where the minimum symbol error rate (MSER) criterion is proposed as a more suitable criterion compared to the commonly used minimum mean square error (MMSE), since MSER directly optimizes the symbol error rate. In this paper, we present a new post-distortion scheme by exploiting the MSER criterion based kernel affine projection algorithm to combat the signal distortion. In addition, to avoid the linearly increased computational complexity, the surprise criterion is introduced for sparsification. Simulations are carried out to validate the performance, and the numerical results show that the proposed method can obtain remarkable performance improvement over the available algorithms.

Highly precise timing alignment of multi-wavelength interleaved cavity-less pulse sources with FROG.

Strictly uniform time interval between adjacent channels is a crucial requirement for the multi-wavelength interleaved (MWI) pulse sources, which difficult alignment can be easily solved by what we believe to be our novel method based on frequency-resolved optical gating (FROG). By utilizing highly precise measurements from FROG, which provide fully two-dimensional information of the pulses in time and frequency domain, we can intuitively identify the time mismatches between different channels in the MWI pulse sources. This enables us to directly align the timing of each channel with sub-picosecond resolution at the first time. MWI pulse sources with total repetition rate of 20.8 GHz (four wavelengths) and 41.6 GHz (eight wavelengths) are precisely aligned by the proposed method, this achievement will pave the way for advancements in photonic analog-digital converters (PADC), high-speed optical communications and so on.

Performance analysis of OFDM with variations in cyclic prefix and FFT lengths

Orthogonal Frequency Division Multiplexing (OFDM) is a modern and suitable modulation strategy for commercial high-speed broadband wireless communication systems. This is because wireless services and demands have grown so quickly in recent years. While creating wireless communication, the channel environment is crucial. A square grid with identical vertical and horizontal spacing is used for the constellation points in quadrature amplitude modulation (QAM). More bits can be transferred per symbol to higher-order modulation forms. This research has looked at how Orthogonal Frequency Division Multiplexing OFDM systems perform using different modulation techniques on channels with additive white Gaussian noise (AWGN). Using MATLAB software to do an experiment with different modulation methods and parameters such as FFT length and cyclic prefix findings showed that 64-QAM modulation sends the same amount of data faster and with fewer symbols than QPSK 16-QAM. Here, the 64-QAM modulation technique performs better. An extensive literature survey has been carried out. The work done here involved working on many parameters to improve the performance of OFDM, i.e., by reducing BER, changing modulation techniques, and analyzing the trade-off between cyclic prefix length and Bit Error Rate. Compared to the existing work, the proposed system provides better performance.

Model of operation of a high-speed satellite communication system for rational distribution of frequency-energy and time resources in the space and ground segment

Model of operation of a high-speed satellite communication system for rational distribution of frequency-energy and time resources in the space and ground segment