scholarly journals On the Feasibility of High Speed Railway mmWave Channels in Tunnel Scenario

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Guangkai Li ◽  
Bo Ai ◽  
Danping He ◽  
Zhangdui Zhong ◽  
Bing Hui ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Communication Systems ◽  
High Speed ◽  
Radio Channel ◽  
Wide Band ◽  
Directional Antenna ◽  
Propagation Loss ◽  
High Rate ◽  
Railway Tunnel ◽  
High Data

Rail traffic is widely acknowledged as an efficient and green transportation pattern and its evolution attracts a lot of attention. However, the key point of the evolution is how to develop the railway services from traditional handling of the critical signaling applications only to high data rate applications, such as real-time videos for surveillance and entertainments. The promising method is trying to use millimeter wave which includes dozens of GHz bandwidths to bridge the high rate demand and frequency shortage. In this paper, the channel characteristics in an arched railway tunnel are investigated owing to their significance of designing reliable communication systems. Meantime, as millimeter wave suffers from higher propagation loss, directional antenna is widely accepted for designing the communication system. The specific changes that directional antenna brings to the radio channel are studied and compared to the performances of omnidirectional antenna. Note that the study is based on enhanced wide-band ray tracing tool where the electromagnetic and scattering parameters of the main materials of the tunnel are measured and fitted with predicting models.

INNOVATIVE METHOD OF SATELLITE COMMUNICATION

2019 ◽  
Author(s):  
Teodor Narytnik ◽  
Vladimir Saiko
Keyword(s):  
Communication Systems ◽  
High Speed ◽  
Satellite Communication ◽  
Radio Channel ◽  
Satellite Communications ◽  
Service Area ◽  
Satellite Systems ◽  
Orbit Satellite ◽  
Geometric Size ◽  
Distributed Satellite

The technical aspects of the main promising projects in the segments of medium and low-orbit satellite communication systems are considered, as well as the project of the domestic low-orbit information and telecommunications system using the terahertz range, which is based on the use of satellite platforms of the micro- and nanosatellite class and the distribution of functional blocks of complex satellite payloads more high-end on multiple functionally related satellites. The proposed system of low-orbit satellite communications represents the groupings of low-orbit spacecraft (LEO-system) with the architecture of a "distributed satellite", which include the groupings of the root (leading) satellites and satellite repeaters (slaves). Root satellites are interconnected in a ring network by high-speed links between the satellites. The geometric size of the “distributed satellite” is the area around the root satellite with a radius of about 1 km. The combination of beams, which are formed by the repeater satellites, make up the service area of the LEO system. The requirements for the integrated service area of the LEO system (geographical service area) determine the requirements for the number of distributed satellites in the system as a whole. In the proposed system to reduce mutual interference between the grouping of the root (leading) satellites and repeater satellites (slaves) and, accordingly, minimizing distortions of the information signal when implementing inter-satellite communication, this line (radio channel) was created in an unlicensed frequency (e.g., in the terahertz 140 GHz) range. In addition, it additionally allows you to minimize the size of the antennas of such a broadband channel and simplify the operation of these satellite systems.

scholarly journals Millimeter Wave Spatial Channel Characterization for Vehicular Communications

Proceedings ◽  
2019 ◽  
Vol 42 (1) ◽  
pp. 64 ◽  
Author(s):  
Fidel Rodríguez-Corbo ◽  
Leyre Azpilicueta ◽  
Mikel Celaya-Echarri ◽  
Peio López-Iturri ◽  
Imanol Picallo ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Autonomous Vehicles ◽  
Communication Systems ◽  
Vehicular Networks ◽  
Small Scale ◽  
Vehicular Communications ◽  
Next Generation ◽  
Vehicular Communication ◽  
High Definition ◽  
High Data

With the growing demand of vehicle-mounted sensors over the last years, the amount of critical data communications has increased significantly. Developing applications such as autonomous vehicles, drones or real-time high-definition entertainment requires high data-rates in the order of multiple Gbps. In the next generation of vehicle-to-everything (V2X) networks, a wider bandwidth will be needed, as well as more precise localization capabilities and lower transmission latencies than current vehicular communication systems due to safety application requirements; 5G millimeter wave (mmWave) technology is envisioned to be the key factor in the development of this next generation of vehicular communications. However, the implementation of mmWave links arises with difficulties due to blocking effects between mmWave transceivers, as well as different channel impairments for these high frequency bands. In this work, the mmWave channel propagation characterization for V2X communications has been performed by means of a deterministic in-house 3D ray launching simulation technique. A complex heterogeneous urban scenario has been modeled to analyze the different propagation phenomena of multiple mmWave V2X links. Results for large and small-scale propagation effects are obtained for line-of-sight (LOS) and non-LOS (NLOS) trajectories, enabling inter-data vehicular comparison. These analyzed results and the proposed methodology can aid in an adequate design and implementation of next generation vehicular networks.

scholarly journals Doppler Shift Estimation for Millimeter-Wave Communication Systems on High-Speed Railways

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 40454-40462 ◽  
Author(s):  
Chong Zhang ◽  
Gongpu Wang ◽  
Minzheng Jia ◽  
Ruisi He ◽  
Li Zhou ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Doppler Shift ◽  
Communication Systems ◽  
High Speed ◽  
Millimeter Wave Communication

scholarly journals ICI Cancellation in OFDM Systems by Frequency Offset Reduction

2014 ◽  
Vol 513-517 ◽  
pp. 3987-3991
Author(s):  
Naveed Ur Rehman ◽  
Lei Zhang ◽  
Muhammad Zahid Hammad ◽  
Emmanuel Anania Mwangosi
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Video Data ◽  
Modulation Scheme ◽  
Ofdm Systems ◽  
Receiver Side ◽  
High Data ◽  
Redundant Data ◽  
Wide Range

The rapid growth within the field of digital communication during the recent years expanded the need for high-speed data transmission to support a wide range of services such as: video, data and voice in wireless communication systems, etc. Orthogonal frequency division multiplexing (OFDM) and a multicarrier modulation scheme are employed to achieve the high data rates. Since OFDM is very much sensitive to carrier frequency offsets, which cause the Inter-carrier Interference (ICI) leads to mitigation of this ICI is necessary. The objectives of this paper are to, proposed an efficient ICI self-cancellation scheme to mitigate the effect of ICI on OFDM systems. For this purpose, a redundant data is transmitted onto adjacent sub-carriers such that the ICI between adjacent sub-carriers cancels out at the receiver side. One data symbol is modulated into a group of adjacent sub carriers with a group of weighting coefficients. At the receiver side, the received signals are linearly combined on these sub carriers with proposed coefficients. The residual ICI contained in the received signals can then be further reduced. This study provides significant carrier-to-interference power ratio (CIR) improvement, which has been studied theoretically and supported by simulations. Since no channel equalization is required to reduce ICI, so the proposed scheme doesnt increase the system complexity.

scholarly journals Wide Band Millimeter Wave Fabric Antenna for 60GHz Applications

2019 ◽  
Vol 8 (9) ◽  
pp. 1211-1214
Keyword(s):  
Millimeter Wave ◽  
Data Communication ◽  
Wide Band ◽  
Processing Unit ◽  
60 Ghz ◽  
Gain Bandwidth ◽  
High Data ◽  
Antenna Performance ◽  
Communication Device ◽  
Millimeter Wave Antenna

A Fabric antenna is used for on body communications. Millimeter wave antenna consists of small beams with high frequency and high directive improves high data communication. It helps us to reduce the barring between user and communication device. This proposed antenna is designed at 60 GHz. It has mainly integrated with wireless sensor network and medical applications. This antenna is designed with the help of HFSS Software. Later HFSS can be explained in the simulation tool. The aim of the paper is, in human body we will insert cloth sensors to monitor different physiological parameters regardless of the patient location. The information passed instantly to the doctor using an external processing unit. In case of any emergency the patient is alerted through appropriate message or alarms. Designed antenna dimensions are 27.3 mm × 8.5 mm × 0.8 mm. Antenna performance is analyzed by using simulated results of reflection co-efficient, VSWR, gain, bandwidth and directivity.

scholarly journals SPREAD SPECTRUM TECHNOLOGY RESEARCH AND ITS APPLICATION IN POWER LINE COMMUNICATION SYSTEMS

T-Comm ◽  
2020 ◽  
Vol 14 (10) ◽  
pp. 45-52
Author(s):  
Edgar M. Dmitriyev ◽  
◽  
Eugeny V. Rogozhnikov ◽  
Andrey K. Movchan ◽  
Semyon M. Mukhamadiev ◽  
...  
Keyword(s):  
Data Transmission ◽  
Spread Spectrum ◽  
Communication Systems ◽  
High Speed ◽  
Transmission Rate ◽  
Power Lines ◽  
Transmission Systems ◽  
Data Transmission Rate ◽  
High Data ◽  
Speed Data Transmission

In the presented article, the results of the research of the spreading spectrum technology are given and its use in communication systems based on the data transmission over power lines is considered. One of the currently existing problems of data transmission systems over power lines is the absence of a compromise solution in ensuring the required data transmission rate and communication range. Ready-made solutions existing on the market provide either high data transmission rates over short distances or a communication long-range with rates not exceeding several tens of kilobits per second. The purpose of the article is to research the application of spread spectrum technology in data transmission systems over power lines. In the course of the experiment, it was found that the joint use of OFDM technology and the spread spectrum technology makes it possible to form a solution that provides communication over power lines over a distance of tens of meters with a data transmission rate of at least 5 Mbps. This article compares the TP-Link 500 Mbps modem for broadband high-speed data transmission, and the NWEPLC-1-G3M modem for narrowband low-speed data transmission. The results of modeling a communication system with different lengths and types of spreading sequences for BPSK and QPSK modulations are presented. An assessment of the interference protection was carried out. The results of an experimental research of the spectrum spreading technology on a model of a data transmission system over power lines in terms of range and transmission rate in comparison with existing devices on the market are presented. The results obtained can be used in the design of communication systems over power lines.

scholarly journals Design and Analysis of a Photonic Crystal Based Planar Antenna for THz Applications

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1941
Author(s):  
Inzamam Ahmad ◽  
Sadiq Ullah ◽  
Shakir Ullah ◽  
Usman Habib ◽  
Sarosh Ahmad ◽  
...  
Keyword(s):  
Communication Systems ◽  
High Speed ◽  
Low Cost ◽  
High Gain ◽  
Propagation Loss ◽  
Smart Devices ◽  
Frequency Range ◽  
Low Profile ◽  
Unit Cells ◽  
Thz Applications

Modern advancements in wearable smart devices and ultra-high-speed terahertz (THz) communication systems require low cost, low profile, and highly efficient antenna design with high directionality to address the propagation loss at the THz range. For this purpose, a novel shape, high gain antenna for THz frequency range applications is presented in this work. The proposed antenna is based on a photonic bandgap (PBG)-based crystal polyimide substrate which gives optimum performance in terms of gain (9.45 dB), directivity (9.99 dBi), and highly satisfactory VSWR (<1) at 0.63 THz. The performance of the antenna is studied on PBGs of different geometrical configurations and the results are compared with the antenna based on the homogeneous polyimide-based substrate. The effects of variations in the dimensions of the PBG unit cells are also studied to achieve a −10 dB bandwidth of 28.97 GHz (0.616 to 0.64 THz).

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