Pilot structure design to increase wireless channel capacity for high-speed railway

Author(s):  
Yongyun Choi ◽  
Jae Hong Lee
2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Jianwen Ding ◽  
Lei Zhang ◽  
Jingya Yang ◽  
Bin Sun ◽  
Jiying Huang

The rapid development of high-speed railway (HSR) and train-ground communications with high reliability, safety, and capacity promotes the evolution of railway dedicated mobile communication systems from Global System for Mobile Communications-Railway (GSM-R) to Long Term Evolution-Railway (LTE-R). The main challenges for LTE-R network planning are the rapidly time-varying channel and high mobility, because HSR lines consist of a variety of complex terrains, especially the composite scenarios where tunnels, cuttings, and viaducts are connected together within a short distance. Existing researches mainly focus on the path loss and delay spread for the individual HSR scenarios. In this paper, the broadband measurements are performed using a channel sounder at 950 MHz and 2150 MHz in a typical HSR composite scenario. Based on the measurements, the pivotal characteristics are analyzed for path loss exponent, power delay profile, and tap delay line model. Then, the deterministic channel model in which the 3D ray-tracing algorithm is applied in the composite scenario is presented and validated by the measurement data. Based on the ray-tracing simulations, statistical analysis of channel characteristics in delay and Doppler domain is carried out for the HSR composite scenario. The research results can be useful for radio interface design and optimization of LTE-R system.


Author(s):  
Gonglian Dai ◽  
Meng Wang ◽  
Tianliang Zhao ◽  
Wenshuo Liu

<p>At present, Chinese high-speed railway operating mileage has exceeded 20 thousand km, and the proportion of the bridge is nearly 50%. Moreover, high-speed railway design speed is constantly improving. Therefore, controlling the deformation of the bridge structure strictly is particularly important to train speed-up as well as to ensure the smoothness of the line. This paper, based on the field test, shows the vertical and transverse absolute displacements of bridge structure by field collection. What’s more, resonance speed and dynamic coefficient of bridge were studied. The results show that: the horizontal and vertical stiffness of the bridge can meet the requirements of <b>Chinese “high-speed railway design specification” (HRDS)</b>, and the structure design can be optimized. However, the dynamic coefficient may be greater than the specification suggested value. And the simply supported beam with CRTSII ballastless track has second-order vertical resonance velocity 306km/h and third-order transverse resonance velocity 312km/h by test results, which are all coincide with the theoretical resonance velocity.</p>


IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 84961-84970 ◽  
Author(s):  
Jianli Xie ◽  
Cuiran Li ◽  
Wenbo Zhang ◽  
Ling Liu

2018 ◽  
Vol 27 (5) ◽  
pp. 1092-1097
Author(s):  
Hua Zhao ◽  
Qing Lyu ◽  
Yachuan Liu ◽  
Jiaxing Chen ◽  
Shujing Zhang

2012 ◽  
Vol 178-181 ◽  
pp. 1279-1286 ◽  
Author(s):  
Xiao Hui Zhang ◽  
Quan Mei Gong ◽  
Shun Hua Zhou

The finite-element method is adopted to analyze the impact of foundation pit construction on close-by railway lines, and related measures are studied to ensure the safety of railway operation during the pit construction. Eventually, cost-effective reinforcement method is recommended, therefor providing a reference for construction of similar foundation pit close to railway lines to determine reinforcement method. The conclusions indicate that under the existing structure design and basal reinforcement design of the foundation pit, the largest settlement of high-speed railway lines is 23.48mm, which does not meet the relative requirements. To reduce the settlement, three rows of high pressure jet grouting piles reinforcement outside the foundation pit and 0.15m away from waterproof curtain is recommended, and 18.0m is considered as the cost-effective reinforcement depth. With the effect of the proposed reinforcement measures, the largest settlement magnitude of high-speed railway subgrade is reduced by 25% to 14.0mm, which meets the relative requirement.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Fengyu Luan ◽  
Yan Zhang ◽  
Limin Xiao ◽  
Chunhui Zhou ◽  
Shidong Zhou

This paper focuses on the fading characteristics of wireless channel on High-Speed Railway (HSR) in hilly terrain scenario. Due to the rapid speed, the fading characteristics of HSR channel are highly correlated with time or Transmit-Receive distance and have their own special property. To investigate the fading characteristics, the measurement is conducted on the Guangzhou-Shenzhen passenger-dedicated line in China with the speed of 295 km/h in the data-collection area at 2.4 GHz. From the measured data, the amplitude of each path is estimated by using the Subspace-Alternating Generalized Expectation-Maximization (SAGE) algorithm along with other parameters of channel impulse responses. Then the fading parameters, including path loss, shadow fading, andK-factor, are analysed. With the numerical results in the measurement and analysis, the fading characteristics have been revealed and modelled. It is supposed that this work has a promotion for HSR communication system design and improvement.


2012 ◽  
Vol 30 (4) ◽  
pp. 834-845 ◽  
Author(s):  
Liu Liu ◽  
Cheng Tao ◽  
Jiahui Qiu ◽  
Houjin Chen ◽  
Li Yu ◽  
...  

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