Large Capacity Data Transmission Research Articles

Enabling high-speed and large-capacity data transmission in optical inter-satellite communication links under various conditions

Enabling high-speed and large-capacity data transmission in optical inter-satellite communication links under various conditions

Analysis of troposcatter communication fading characteristics under different weather conditions

Received signals of troposcatter communication are closely related to the weather, and there are currently few short-term analyses of the signals. The basic mode of troposcatter communication and the influence principle of weather system on the received signal were analyzed, the typical troposcatter communication link in North China was observed for a long time, the observation samples under different weather conditions on sunny and rainy days were selected, and the fading of the received signal was statistically analyzed, including signal fading, fading depth and fading speed, which provided reference for the tactical application of troposcatter communication equipment. On rainy days, or from 9 o'clock to 17 o'clock of sunny days, the propagation mode is mainly turbulent scattering, and the signal quality is poor, so it is not suitable to plan heavy-load tasks; From 19 o'clock to 8 o'clock the next morning of sunny days, the propagation mode is mainly stable layer reflection, and atmospheric waveguides often appear, and the quality of the received signal will be greatly enhanced, which can ensure large-capacity data transmission.

Design and analysis of a weakly coupled few-mode hollow-core U-shaped tube nested antiresonant fiber

In this work, we proposed a weakly coupled few-mode hollow-core U-shaped tube nested antiresonant fiber (FM-UARF) for the potential large-capacity mode-division multiplexing transmission without multiple-in-multiple-out (MIMO) digital signal processing. Through theoretical analysis and numerical simulation, the six-tube FM-UARF can be a good candidate for two-mode and three-mode transmission with better performance. After parameter optimization, the weakly coupled condition of effective refractive index difference (Δneff) larger than 5×10−4 can be achieved. Under the two-mode case, the confinement loss (CL) of the LP01 and LP11 modes is less than 0.005 dB/km and 0.1 dB/km in the 700 nm bandwidth range (0.9−1.6µm), respectively. In addition, LP01 achieves the lowest CL of 0.00038 dB/km at a wavelength of 1.06 µm, which gives it potential applications in high-power laser transmission. Under the three-mode case, the CL of the LP01, LP11, and LP21 modes are less than 0.006 dB/km, 0.1 dB/km, and 10 dB/km, respectively, in the wavelength range of 0.95 to 1.65 µm. Both the CL ratios are larger than 150 (23 dB), which ensures the high purity of the supported fiber modes. The results show that the proposed FM-UARF with optimized parameters has the potential in the MIMO-less large-capacity data transmission and so on.

Review on Radio over Fiber Systems for Capacity Enhancement

Radio-over-fiber (RoF) system is one of the latest plans for future wideband wireless communication systems like mobile communications, suburban and residential areas. These are good nominees to build the backbone of the next generation of wireless networks. Besides, the fundamental requirement for next-generation radio optical fiber and mobile communication is the need for more capacity and speed which has a huge scope, that is further required for a better system to attain demands such as Fiber to The Home (FTTH) and 5G. The combination of RoF with spectrally-efficient modulation techniques can accomplish increasing demand for high data rates for mobile users. Currently, analog fronthaul is promoted as an energy-efficient and bandwidth solution that can reach the necessity of the 5G vision for high data rates, low latency, and energy efficiency. Mainly, this paper presents a review that focuses on various techniques which several approaches have been listed to perceive the large-capacity data transmission and describe them including Wavelength Division Multiplexing (WDM), Subcarrier Multiplexing (SCM), Mode Division Multiplexing (MDM), Polarization Division Multiplexing (PDM), Generalized Frequency Division Multiplexing (GFDM), Parallel  Intensity Modulation (PIM)/Phase Modulation (PM) transmitter, and Millimeter-wave (Mm wave) generation techniques. Also, a comparison between them has been done

Tracking Efficiency Improvement According to Incident Beam Size in QPD-Based PAT System for Common Path-Based Full-Duplex FSO Terminals.

Free space optical (FSO) communication can support various unmanned aerial vehicles’ (UAVs) applications that require large capacity data transmission. In order to perform FSO communication between two terminals, it is essential to employ a pointing, acquisition, and tracking (PAT) system with an efficient and optimal performance. We report on the development of a common optical-path-based FSO communication system, tailored for applications in UAVs. The proposed system is equipped with a quadrant photodiode (QPD)-based PAT system without an additional beacon beam subsystem. The presented approach reduced the structural complexity and improved the tracking efficiency for the same size, weight, and power (SWaP). To achieve a robust FSO link in a dynamic UAV environment, the observability and controllability were obtained based on the linearized control according to the incident beam size on the QPD, which was verified by optical simulation and experiments. As a result, the QPD-based PAT system for implementing FSO links demonstrated an up to 4.25 times faster tracking performance. Moreover, the FSO link experimentally confirmed the 1.25 Gbps full-duplex error-free communication at a 50 m distance.

Simulation of Multisensor Energy Data Fusion Transformer Acquisition System Based on FPGA

In order to solve the problems of small signal acquisition range and poor acquisition accuracy of the existing multichannel acquisition system, a multisensor energy data fusion transformer acquisition system simulation method based on FPGA is proposed, and key hardware functions are designed and implemented. The system uses FPGA to control the core logic, synchronously collects and controls the energy data of the CCD camera and the laser rangefinder, organizes and uses an external large-capacity SDRAM group for buffering, and uses a dedicated PCI interface chip PLX9656 to achieve high-speed data transmission. Two pieces of sensor energy data and PCI bus energy data are stored in real time using a large-capacity disk array composed of multiple SATA hard disks. The function and performance of the energy data acquisition and storage system were tested. After the actual system test, the experimental results show that the transmission speed of the system through the PCI bus exceeds 200 MB/s, the writing speed of the continuous disk array is 240 MB/s, and the real-time acquisition and recording speed is 100 MB/ss. Conclusion. The system effectively solves the problems of high-speed data acquisition and storage and large capacity data transmission of key sensor nodes.

Power Grid Resource Integration of Enterprise Middle Station based on Analytic Hierarchy Process

With the transformation from smart grid to power Internet of Things, new power businesses such as power grid automation and power quality monitoring are constantly emerging. The load environment of power grid is changeable. In order to meet the needs of multi-service, the integrated access scheme for power grid resources in power enterprises is gradually diversified, which brings challenges to the unified management and control of power grid communication network. In this paper, SDN technology is used to improve the operation and maintenance management and control of power communication network, which aims at the integration scheme of power grid resources in power enterprises. Based on the controller cluster technology, combined with the new power business requirements, this paper designs a software-defined network centralized control architecture of the new business of power communication network. The architecture realizes the operation and maintenance management of network resources under the centralized control architecture of typical enterprise scenarios, such as power grid enterprises. The convergence speed is improved by 27%. The minimum value of iterative convergence is 31% better than that of other methods. The system requirement is reduced by 13.5%, which is helpful to improve the efficiency of node dynamic allocation and ensure the need of large-capacity data transmission of smart grid. The research in this paper can realize the two-way interaction, real-time expansion and unified deployment of power business in the future, and promote the intensive and lean development of power communication network.

Wideband low confinement loss anti-resonant hollow core fiber with nested U-shape tube.

We propose a nested U-shape tube anti-resonant hollow core fiber (UARF) that can effectively reduce the confinement loss (CL) as well as the loss oscillations. The key parameters of UARF have been optimized via numerical analysis. Simulation results show that the CL of proposed UARF is lower than 0.01dB/km over a 550 nm operational bandwidth range from 1.3 µm to 1.85 µm. This CL is nearly one order of magnitude lower than the nested anti-resonant nodeless fiber (NANF). Moreover, the loss ratio between higher-order modes to the fundamental mode is verified to be more than 100,000 over a ultrawide bandwidth of 1000 nm, which indicates its excellent single mode performance. The tolerance towards the structure deformation of UARF has been evaluated for the purpose of practical fiber fabrication. Thus, the proposed UARF has potential application in large capacity data transmission, nonlinear optics, gas sensing and so on.

Channel Sounding and Scene Classification of Indoor 6G Millimeter Wave Channel Based on Machine Learning

Millimeter wave, especially the high frequency millimeter wave near 100 GHz, is one of the key spectrum resources for the sixth generation (6G) mobile communication, which can be used for precise positioning, imaging and large capacity data transmission. Therefore, high frequency millimeter wave channel sounding is the first step to better understand 6G signal propagation. Because indoor wireless deployment is critical to 6G and different scenes classification can make future radio network optimization easy, we built a 6G indoor millimeter wave channel sounding system using just commercial instruments based on time-domain correlation method. Taking transmission and reception of a typical 93 GHz millimeter wave signal in the W-band as an example, four indoor millimeter wave communication scenes were modeled. Furthermore, we proposed a data-driven supervised machine learning method to extract fingerprint features from different scenes. Then we trained the scene classification model based on these features. Baseband data from receiver was transformed to channel Power Delay Profile (PDP), and then six fingerprint features were extracted for each scene. The decision tree, Support Vector Machine (SVM) and the optimal bagging channel scene classification algorithms were used to train machine learning model, with test accuracies of 94.3%, 86.4% and 96.5% respectively. The results show that the channel fingerprint classification model trained by machine learning method is effective. This method can be used in 6G channel sounding and scene classification to THz in the future.

A study on VAL platform for 5G network for large-capacity data transmission

Recently, a lot of researches have been conducted on a platform that provides a Visual Programming development environment capable of 3D editing and interactive editing in an In-VR (Virtual Reality) environment so that VR/AR (Augmented Reality) contents can be quickly worked on. In this paper, a functional language-based VR/AR specialized language(VAL) and Visual Language were developed, and VR/AR prototypes were easily implemented using these languages on the platform. Then, prototypes based on the 5G network can be shared and collaborated with others, and content creation can be continued in Unity and Unreal without interruption. In addition, this paper shows the recognition process for users, the PS/CS check process and the node processing process for transmitting content by limiting the process for transmitting VAL-based mass data in 5G environment. The proposed platform can easily create a prototype of their intended VR/AR App (or content) even for users (beginners) who do not have a certain level of knowledge and experience in 3D graphics and software coding, and share it with others. It has characteristics that can be done. Consequently, we propose a method to use VAL more effectively in a 5G environment.

Review on the Millimeter-Wave Generation Techniques Based on Photon Assisted for the RoF Network System

With the development trend of wireless and broadband in the communication link and even the whole information industry, the demand of high-frequency microwave bandwidth has been increasing. The RoF network system solves the problem of spectrum congestion in low-frequency band by providing an effective technology for the distribution of high-frequency microwave signals over optical fiber links. However, the traditional mm-wave generation technique is limited by the bandwidth of electronic devices. It is difficult to generate high-frequency and low-phase noise mm-wave signals with pure electrical components. The mm-wave communication technology based on photon assisted can overcome the bandwidth bottleneck of electronic devices and provide the potential for developing the low-cost infrastructure demand of broadband mobile services. This paper will briefly explain the characteristics of the RoF network system and the advantages of high-frequency mm-wave. Then we, respectively, introduce the modulation schemes of RoF mm-wave generation based on photon assisted including directly modulated laser (DML), external modulation, and optical heterodyne. The review mainly focuses on a variety of different mm-wave generation technologies including multifrequency vector mm-wave. Furthermore, we list several approaches to realize the large capacity data transmission techniques and describe the digital signal processing (DSP) algorithm flow in the receiver. In the end, we summarize the RoF network system and look forward to the future.

Experimental demonstration of generating arbitrary total angular momentum states

We experimentally demonstrated an approach to generate arbitrary total angular momentum (TAM) states by using two liquid crystal devices. Photons’ TAM, the sum of spin and orbital angular momenta (SAM and OAM) under paraxial approximation, has found many applications in optics and attracted increasing attention in recent years. Our approach is based on the orthogonality of two eigen SAM components, that arbitrary TAM states will be produced through encoding different holograms in one system. The comparison with theoretical predications yields an excellent agreement, including both the separable state and the non-separable state. The proposed scheme takes a step forward for generating complex structured fields and broadens its application to various fields like laser processing and large capacity data transmission.

A Comprehensive Survey on Millimeter Wave Communications for Fifth-Generation Wireless Networks: Feasibility and Challenges

Fifth-generation (5G) cellular networks will almost certainly operate in the high-bandwidth, underutilized millimeter-wave (mmWave) frequency spectrum, which offers the potentiality of high-capacity wireless transmission of multi-gigabit-per-second (Gbps) data rates. Despite the enormous available bandwidth potential, mmWave signal transmissions suffer from fundamental technical challenges like severe path loss, sensitivity to blockage, directivity, and narrow beamwidth, due to its short wavelengths. To effectively support system design and deployment, accurate channel modeling comprising several 5G technologies and scenarios is essential. This survey provides a comprehensive overview of several emerging technologies for 5G systems, such as massive multiple-input multiple-output (MIMO) technologies, multiple access technologies, hybrid analog-digital precoding and combining, non-orthogonal multiple access (NOMA), cell-free massive MIMO, and simultaneous wireless information and power transfer (SWIPT) technologies. These technologies induce distinct propagation characteristics and establish specific requirements on 5G channel modeling. To tackle these challenges, we first provide a survey of existing solutions and standards and discuss the radio-frequency (RF) spectrum and regulatory issues for mmWave communications. Second, we compared existing wireless communication techniques like sub-6-GHz WiFi and sub-6 GHz 4G LTE over mmWave communications which come with benefits comprising narrow beam, high signal quality, large capacity data transmission, and strong detection potential. Third, we describe the fundamental propagation characteristics of the mmWave band and survey the existing channel models for mmWave communications. Fourth, we track evolution and advancements in hybrid beamforming for massive MIMO systems in terms of system models of hybrid precoding architectures, hybrid analog and digital precoding/combining matrices, with the potential antenna configuration scenarios and mmWave channel estimation (CE) techniques. Fifth, we extend the scope of the discussion by including multiple access technologies for mmWave systems such as non-orthogonal multiple access (NOMA) and space-division multiple access (SDMA), with limited RF chains at the base station. Lastly, we explore the integration of SWIPT in mmWave massive MIMO systems, with limited RF chains, to realize spectrally and energy-efficient communications.

Overview of Vehicle Optical Wireless Communications

Effective information transmission between vehicles has become one of the solutions to improve road safety. Based on the huge advantages of optical wireless data transmission technology, this article summarizes the research status of unmanned vehicles in optical wireless communication (OWC). The article not only studies the actual progress of building optical links through an unmanned vehicle, connecting air communication, ground communication, underwater communication into a unified wireless network, and realizing the fast, stable, large-capacity data transmission system. The technical challenges of unmanned vehicle OWC are also discussed and its future development has prospected.

Multi-Node All-Optical Interconnect Network Routing for Data-Center Parallel Computers

A multi-node all-optical interconnect network-routing architecture scheme and implementation technology are designed to improve high-speed and large-capacity data transmission in data centers. In the design of the optical interconnect routing electro-optic printed circuit board (EOPCB), the signal generated by the FPGA is directly modulated by the VCSEL arrays, and through the coupler into the parallel optical waveguide. The transmission link and optical switch are operated in optical domain. The designed optical waveguide comprises 12 waveguide arrays with the space of 250 μm. The all-optical interconnection routing system, which is based on the EOPCB high-speed chip multi-node waveguide, is designed, and a 4 × 4 EOPCB is fabricated. The performance of the waveguide and the entire optical interconnection network is tested. Based on 10 Gb/s VCSEL arrays, the optical interconnect network system can reach a bandwidth of 640 GHz for 4 × 4 networks. The best bit error rate for the switching system can reach 9.0 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-12</sup> with no transmission error.

Rectangular Array Multicore Fiber Realizing Low Crosstalk Suitable for Next-Generation Short-Reach Optical Interconnects With Low Misalignment Loss

Toward the next-generation exa-scale short-reach optical interconnects (OIs) supporting large-capacity data transmission, a compact computer-compatible 8-core heterogeneous trench-assisted multicore fiber (TA-MCF) is proposed, in which cores are arranged in a rectangular array. To analyze the crosstalk (XT) between adjacent cores of TA-MCF OI, a rigorous full-vectorial H- field finite element method (FEM) and coupled power theory are applied. The impact of various trench design parameters on the mode-coupling coefficient C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mn</sub> and the coupling length L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> is discussed in detail. An accurate explicit condition for the achievement of low XT in an 8-core heterogeneous TA-MCF OI is obtained through numerical simulations. A rigorous modal solution approach based on the computationally efficient FEM and the least squares boundary residual method is employed to analyze the coupling loss caused by the misalignment to a butt-coupled TA-MCF OI.

Experimental demonstration of large capacity WSDM optical access network with multicore fibers and advanced modulation formats.

Towards the next generation optical access network supporting large capacity data transmission to enormous number of users covering a wider area, we proposed a hybrid wavelength-space division multiplexing (WSDM) optical access network architecture utilizing multicore fibers with advanced modulation formats. As a proof of concept, we experimentally demonstrated a WSDM optical access network with duplex transmission using our developed and fabricated multicore (7-core) fibers with 58.7km distance. As a cost-effective modulation scheme for access network, the optical OFDM-QPSK signal has been intensity modulated on the downstream transmission in the optical line terminal (OLT) and it was directly detected in the optical network unit (ONU) after MCF transmission. 10 wavelengths with 25GHz channel spacing from an optical comb generator are employed and each wavelength is loaded with 5Gb/s OFDM-QPSK signal. After amplification, power splitting, and fan-in multiplexer, 10-wavelength downstream signal was injected into six outer layer cores simultaneously and the aggregation downstream capacity reaches 300 Gb/s. -16 dBm sensitivity has been achieved for 3.8 × 10-3 bit error ratio (BER) with 7% Forward Error Correction (FEC) limit for all wavelengths in every core. Upstream signal from ONU side has also been generated and the bidirectional transmission in the same core causes negligible performance degradation to the downstream signal. As a universal platform for wired/wireless data access, our proposed architecture provides additional dimension for high speed mobile signal transmission and we hence demonstrated an upstream delivery of 20Gb/s per wavelength with QPSK modulation formats using the inner core of MCF emulating a mobile backhaul service. The IQ modulated data was coherently detected in the OLT side. -19 dBm sensitivity has been achieved under the FEC limit and more than 18 dB power budget is guaranteed.

Design of USB2.0 Data Exchanging System Based on FPGA

For achieving high-speed and large-capacity data transmission between two computers, a data exchanging system is designed. With FPGA as the data transmission medium, the exchanging of command and data is implemented through the I2C channel and Slave FIFO channel of USB2.0 chip. The system design includes both hardware and software, which are respectively realized by Verilog HDL and C++. Two computers with USB Host interfaces are connected to the development board by USB2.0 transmission line, and then exchange data directly under the control of upper computer. The simulation results show that the system is practical, reliable and easily extensible.

The Communication Protocol Research of Rail Train Safety Monitoring Sensor Network

Today, the rail traffic as a large capacity public transportation way gets rapid development in the world, in order to guarantee the trains safety, people use train network to monitor the trains real time status. But with the developing of safety requirement, the traditional MVB networks low transmission rate has been unable to meet the train safety monitorings large capacity data transmission requirement, so people put forward the idea of industrial Ethernet. Industrial Ethernet although can meet the requirement of large capacity, high rate transmission requirement, but still in the initial development stage, there has no unified transmission protocol and interface specification, so research on transmission standard of train safety monitoring network with great data transmission capacity has become the new development direction.

RF CMOS Integrated Circuit: History, Current Status and Future Prospects

As great advancements have been made in CMOS process technology over the past 20 years, RF CMOS circuits operating in the microwave band have rapidly developed from component circuit levels to multiband/multimode transceiver levels. In the next ten years, it is highly likely that the following devices will be realized: (i) versatile transceivers such as those used in software-defined radios (SDR), cognitive radios (CR), and reconfigurable radios (RR); (ii) systems that operate in the millimeter-wave or terahertz-wave region and achieve high speed and large-capacity data transmission; and (iii) microminiaturized low-power RF communication systems that will be extensively used in our everyday lives. However, classical technology for designing analog RF circuits cannot be used to design circuits for the abovementioned devices since it can be applied only in the case of continuous voltage and continuous time signals; therefore, it is necessary to integrate the design of high-speed digital circuits, which is based on the use of discrete voltages and the discrete time domain, with analog design, in order to both achieve wideband operation and compensate for signal distortions as well as variations in process, power supply voltage, and temperature. Moreover, as it is thought that small integration of the antenna and the interface circuit is indispensable to achieve miniaturized micro RF communication systems, the construction of the integrated design environment with the Micro Electro Mechanical Systems (MEMS) device etc. of the different kind devices becomes more important. In this paper, the history and the current status of the development of RF CMOS circuits are reviewed, and the future status of RF CMOS circuits is predicted.