High-Capacity and High-Spectral-Efficiency Seamless Fiber-Wireless System for High-Speed Trains

2016 ◽  
Author(s):  
Pham Tien Dat ◽  
Atsushi Kanno ◽  
Naokatsu Yamamoto ◽  
Tetsuya Kawanishi
Keyword(s):  
Spectral Efficiency ◽  
High Speed ◽  
High Capacity ◽  
Wireless System ◽  
High Spectral Efficiency ◽  
High Speed Trains

Enhancement of Performance of Multi Diagonal Code OCDMA System Using OFDM Technique

2014 ◽  
Vol 679 ◽  
pp. 30-34 ◽  
Author(s):  
A.O. Aldhaibani ◽  
S.A. Aljunid ◽  
M.S. Anuar ◽  
A.R. Arief
Keyword(s):  
Cost Effectiveness ◽  
Spectral Efficiency ◽  
High Capacity ◽  
Access Networks ◽  
Next Generation Networks ◽  
High Spectral Efficiency ◽  
Efficiency Cost ◽  
Promising Solution ◽  
Improved Performance ◽  
Theoretical Results

In this paper, we describe the improved performance of the SAC-OCDMA system using OFDM technique compared to SCM/SAC-OCDMA system. The theoretical results of proposed system shows that the new SAC/OCDMA system with OFDM technique provides better performance compared to SCM/OCDMA system based on multi diagonal code (MD), and the results have been evaluated based on BER and number of users for bit rate 1Gb/s and 10 Gb/s . Thus this system could be a promising solution to symmetric high capacity access networks with high spectral efficiency, cost effectiveness, good flexibility and enhanced security, which is candidate for next generation networks.

High-Speed and Handover-Free Communications for High-Speed Trains Using Switched WDM Fiber–Wireless System

2018 ◽  
Author(s):  
Pham Tien Dat ◽  
Atsushi Kanno ◽  
Keizo Inagaki ◽  
Toshimasa Umezawa ◽  
François Rottenberg ◽  
...  
Keyword(s):  
High Speed ◽  
Wireless System ◽  
High Speed Trains

A new methodology for the assessment of the running resistance of trains without knowing the characteristics of the track: Application to full-scale experimental data

2018 ◽  
Vol 232 (6) ◽  
pp. 1814-1827 ◽  
Author(s):  
Claudio Somaschini ◽  
Tommaso Argentini ◽  
Daniele Rocchi ◽  
Paolo Schito ◽  
Gisella Tomasini
Keyword(s):  
High Speed ◽  
High Capacity ◽  
Full Scale ◽  
Design Stage ◽  
Resistance Force ◽  
Full Scale Test ◽  
High Speed Trains ◽  
Scale Test ◽  
Full Scale Tests ◽  
Resistance Coefficients

The resistance to motion of trains is an essential requisite especially while designing high-speed trains and high-capacity railway lines. The optimisation of friction effects and aerodynamic performance can be done during the design stage of a new train but the actual value of the running resistance can be inferred only by means of full-scale tests during the operation of a train. A CEN standard (EN 14067-4) describes the methodologies for the assessment of the running resistance of railway vehicles starting from full-scale test measurements. According to this standard, the speed-dependent terms of the resistance force have to be determined by means of coasting tests on railway lines, whose characteristics must be well known. Since this is not always possible and small errors on the gradient could lead to major uncertainties in the evaluation of the resistance force, a new method for the estimation of the running resistance coefficients, irrespective of the characteristics of the track is proposed in this paper. The reliability of the method is verified by comparing the results with those obtained from the procedure proposed in the CEN standard. The comparison shows that the new methodology is able to evaluate the resistance coefficients with an accuracy equivalent to that of the other methods but with fewer tests and with a more robust procedure relying on a lesser number of parameters.

An Improved Algorithm Based on Optimized PTS in MIMO-OFDM System

2013 ◽  
Vol 765-767 ◽  
pp. 2801-2804
Author(s):  
Ya Jing Wang ◽  
Ya Zhen Li ◽  
Li Qun Huang
Keyword(s):  
Spectral Efficiency ◽  
Communication System ◽  
High Speed ◽  
Fourth Generation ◽  
Ofdm System ◽  
Broadband Wireless ◽  
High Spectral Efficiency ◽  
Mimo Ofdm ◽  
Simulation Results ◽  
Improved Algorithm

The fourth generation mobile communication system is a high-speed broadband wireless communication system, it needs MIMO and OFDM technology which have high spectral efficiency and suitable for a multi-path fading channel. Because the MIMO-OFDM system is still an multi-carrier modulation system, the main drawback is the high PAPR value. This paper proposed an improved algorithm based on optimized PTS to reduce PAPR in STBC MIMO-OFDM system. The simulation results show that the improved algorithm can effectively reduce the PAPR value and do not increase the amount of computation in STBC MIMO-OFDM system.

Radio over Fibre Transport of Alamouti-coded MIMO Signals with Self-Recovery Capability

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Jaswinder Kaur ◽  
Vishal Sharma
Keyword(s):  
Spectral Efficiency ◽  
High Speed ◽  
Multipath Fading ◽  
Block Code ◽  
Wireless Channel ◽  
Modulation Scheme ◽  
Wireless Data ◽  
Wireless System ◽  
Radio Over Fibre ◽  
The Impact

AbstractRadio over Fibre (RoF) transport of high-speed wireless data provides a comprehensive solution for the forthcoming highly-reliable and spectral-efficient wireless systems. MIMO is one of the most widely used wireless technologies to increase the system reliability and capacity without any increased demand of power/bandwidth. However, the inherent non-linearities of RoF link and the multipath fading of the wireless channel can degrade the overall performance of the wireless system. In this work, authors demonstrate RoF transport of adaptively modulated MIMO signals and report the improvement in spectral efficiency under the impact of RoF link non-linearity. The transmitter of the proposed RoF based wireless system selects the appropriate modulation scheme with the assumption of perfect channel state information to achieve the acceptable BER at the subscriber end. The spectral efficiency improvement by this self-recovering MIMO-RoF system is evaluated by incorporating orthogonal Space-Time Block Code with 2 × 2 antenna configuration over the frequency-selective Rayleigh fading channel.

scholarly journals HERMITIAN SYMMETRY BASED FIBER NON-LINEARITY COMPENSATION IN OPTICAL OFDM NETWORKS

2013 ◽  
pp. 8-14
Author(s):  
KAMALA KANNAN P ◽  
GURU VIGNESH B ◽  
INIYAN P A ◽  
ILAVARASAN T
Keyword(s):  
Optical Fiber ◽  
Optical Networks ◽  
Spectral Efficiency ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Power Level ◽  
Optical Fiber Communication ◽  
High Spectral Efficiency ◽  
Optical Ofdm

Orthogonal Frequency Division Multiplexing (OFDM) is a modulation technique which is now used in most new and emerging broadband wired and wireless communication systems such as standard 802.11a/b/g/n, Digital Video Broad casting Television (DVB-TV), and Long Term Evolution (LTE) in the next mobile generation, due to its capacity in solving the problems of Inter-Symbol Interference (ISI) caused by the effects of the dispersive channel. Very recently researches focus on applying OFDM technology in optical fiber communication systems. Optical OFDM is well suited for high speed transmission systems with high spectral efficiency and attracted significant attention from the optical communication community. One of the major issues that degrade the performance of optical OFDM networks is its fiber non-linearity. Fiber non-linearities represent the fundamental limiting mechanisms to the amount of data that can be transmitted on a single optical fiber. Non-linear effects arise as optical fiber data rates, transmission lengths, number of wavelengths, and optical power level increases. Therefore, the effect of non-linearity in high data rate optical networks needs to be controlled to enhance link performances. In this paper, a nonlinearity compensation technique (Hermitian Symmetry) is implemented to improve the performance of OFDM based optical networks. This would provide high spectral efficiency, low ISI and very good Bit Error Rate (BER) performances without increasing the complexity of the network. The optical OFDM transmission system with fiber non-linearity compensation is simulated using Virtual Photonics Integrated (VPI) software.

scholarly journals A Comparative Study of 4G and VoLTE

2021 ◽  
Vol 9 (12) ◽  
pp. 2338-2341
Author(s):  
Atharva Khandekar
Keyword(s):  
High Speed ◽  
Cost Effective ◽  
Fourth Generation ◽  
Wireless System ◽  
Data Services ◽  
High Spectral Efficiency ◽  
High Speed Data ◽  
4G Wireless ◽  
4G Lte ◽  
Voice Calls

Abstract: This research paper provides an insight into the comparison between VoLTE and 4G. 4G Wireless Systems or Fourth generation wireless system is a packet switched wireless system with wide area coverage and high throughput. It is designed to be cost effective and to provide high spectral efficiency. VoLTE (voice over LTE) supports voice calls over 4G LTE network. With advanced VoLTE technology, the 4G network now provides high-speed data services, high-quality voice and video calls at affordable price. This paper first presents the challenges and benefits of both 4G and VoLTE and then compares them with consideration of different points. Keywords: GSM, LTE, VoLTE, 3G, HSPA, RAN

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