Downlink data transmission for high-speed trains in 5G communication systems

2020 ◽  
Vol 14 (18) ◽  
pp. 3175-3183
Author(s):  
Vahid Vahidi ◽  
Ebrahim Saberinia
2015 ◽  
Vol 793 ◽  
pp. 523-529
Author(s):  
Mahmoud A.M. Albreem ◽  
Azuwa binti Ali

Block Data Transmission Systems (BDTS) are used in high speed wireless communication systems with time dispersive channel characteristics. Since Maximum Likelihood Block Detection (MLBD) requires huge amount of computation, Sphere Detection (SD) technique has been introduced as an alternative. This paper proposes an An Lattice Sphere Detection (AnLSD) technique for detection in block data transmission systems (BDTS). The An lattice structure offers more dense constellation points than the customary Zn lattice in SD technique. Thus, the proposed AnLSD uses An lattice generator matrix as the channel matrix, and uses the Gram matrix which is obtained from the generator matrix as part of the detection process. Simulation results show that the proposed AnLSD performs very close to the Exhaustive search (ES) using block size of 20 bits. It is also performing better than the other renowned methods tested under a channel with spectral nulls. The proposed AnLSD technique offers significant reduction in term of objective functions evaluation as compared to the other renowned methods.


T-Comm ◽  
2020 ◽  
Vol 14 (10) ◽  
pp. 45-52
Author(s):  
Edgar M. Dmitriyev ◽  
◽  
Eugeny V. Rogozhnikov ◽  
Andrey K. Movchan ◽  
Semyon M. Mukhamadiev ◽  
...  

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.


2020 ◽  
Vol 12 (11) ◽  
pp. 179
Author(s):  
Magdalena Garlinska ◽  
Agnieszka Pregowska ◽  
Karol Masztalerz ◽  
Magdalena Osial

Fast communication is of high importance. Recently, increased data demand and crowded radio frequency spectrum have become crucial issues. Free-Space Optical Communication (FSOC) has diametrically changed the way people exchange information. As an alternative to wire communication systems, it allows efficient voice, video, and data transmission using a medium like air. Due to its large bandwidth, FSOC can be used in various applications and has therefore become an important part of our everyday life. The main advantages of FSOC are a high speed, cost savings, compact structures, low power, energy efficiency, a maximal transfer capacity, and applicability. The rapid development of the high-speed connection technology allows one to reduce the repair downtime and gives the ability to quickly establish a backup network in an emergency. Unfortunately, FSOC is susceptible to disruption due to atmospheric conditions or direct sunlight. Here, we briefly discuss Free-Space Optical Communication from mirrors and optical telegraphs to modern wireless systems and outline the future development directions of optical communication.


2017 ◽  
Vol 39 (1) ◽  
Author(s):  
Abdallah Ahmad Shatnawi ◽  
Mohd Nazri Bin Mohd Warip ◽  
Anuar Mat Safar

AbstractInter-satellite communication is one of the revolutionary techniques that can be used to transmit the high speed date between satellites. However, space turbulences such as transmitting pointing errors play a significant role while designing inter-satellite communication systems. Those turbulences cause shutdown of inter-satellite link due to increase of attenuation during data transmission through link. The present work aims to develop an integrated data transmission system incorporating alternate mark inversion (AMI), wavelength division multiplexing (WDM), and polarization interleaving (PI) scheme for transmitting data 160 Gbps over inter-satellite link of 1,000 km under the influence of space turbulences. The performance of the integrated data transmission of 160 Gbps data up to 1,000 km will be evaluated under the influence of space turbulences by means of signal to noise ratio (SNR), total received power, bit error rate and eye diagram.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Abhijot kaur ◽  
Neeraj Sharma ◽  
Jatinder Singh

AbstractFree space optics (FSO) can be used as an alternative to the currently used wireless radio communication systems to meet the increasing demands for the uninterrupted internet connection in High-Speed Trains (HSTs). FSO is less prone to interference, license-free and more secure as compared to Radio Frequency (RF) technology. In this paper, we have compared three different wavelengths (850, 1330, and 1550 nm) for the dual-wavelength model at a bit rate of 10 Gb/s to see which two wavelengths provide better results. The system is studied for return to zero (RZ) and non-return to zero (NRZ) modulation formats this electronic document is a “live” template and already defines the components of your paper [title, text, heads, etc.] in its style sheet.


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