scholarly journals Investigation of Shadowing Effects in Typical Propagation Scenarios for High-Speed Railway at 2350 MHz

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Liu Liu ◽  
Cheng Tao ◽  
David W. Matolak ◽  
Tao Zhou ◽  
Houjin Chen
Keyword(s):  
Wireless Communication ◽  
Mean Square Error ◽  
Exponential Function ◽  
High Speed ◽  
Test Method ◽  
Wide Sense ◽  
Mean Square ◽  
Matching Model ◽  
High Speed Railway ◽  
Correlation Models

Based on realistic measurements in China, shadowing characteristics at the frequency of 2350 MHz were investigated in typical High-Speed Railway environments. After confirming that the measured shadowing satisfies wide-sense stationarity (assessed via the reverse arrangement test method), we quantify the shadowing correlation. Three types of correlation models are compared for the shadowing characterization, and the Normalized Mean Square Error is used to determine the best matching model: a single decaying exponential function. Decorrelation distances were found to be 11.9 m, 17.7 m, and 8.3 m in our three HSR scenarios, respectively. The results should be useful for the evaluation and verification of wireless communication in High-Speed Railway scenarios.

Analysis of Dropped-Call Probability in Relay-Based High Speed Railway Environment

2015 ◽  
Vol 738-739 ◽  
pp. 1129-1132
Author(s):  
Yun Ze Li ◽  
Xin Yu Jin ◽  
Duan Po Wu
Keyword(s):  
Wireless Communication ◽  
High Speed ◽  
Base Stations ◽  
Call Rate ◽  
Coverage Area ◽  
High Speed Railway ◽  
Ping Pong ◽  
Order Of Magnitude

In poor coverage area of high-speed railway, the frequent handoff will increase the dropped-call rate. An approach to improving the quality of wireless communication is adding a relay between two base stations. Paper is about analyzing the dropped-call caused by handoff in this scene. This paper proposed a model for dropped-call probability through analyzing the handoff probability, same frequency interference and ping-pong handoff. Based on the simulation and comparison of the dropped-call model, we found that putting a relay between the base stations can significantly improve the dropped-call problem, and the peek rate of dropped-call decreased by an order of magnitude.

Design and Implementation of Adaptive FIR filter using Systolic Architecture

2014 ◽  
Vol 3 (2) ◽  
pp. 54
Author(s):  
Ravi H Bailmare ◽  
S.J. Honale ◽  
Pravin V Kinge
Keyword(s):  
Mean Square Error ◽  
Integrated Circuit ◽  
High Speed ◽  
Minimum Mean Square Error ◽  
Weight Vector ◽  
Internet Technology ◽  
Mean Square ◽  
Systolic Architecture ◽  
Field Programmable ◽  
Hardware Description

<p>The tremendous growth of computer and Internet technology wants a data to be process with a high speed and in a powerful manner. In such complex environment, the conventional methods of performing multiplications are not suitable to obtain the perfect solution. To obtain perfect solution parallel computing is use in contradiction. The DLMS adaptive algorithm minimizes approximately the mean square error by recursively altering the weight vector at each sampling instance. In order to obtain minimum mean square error and updated value of weight vector effectively, systolic architecture is used. Systolic architecture is an arrangement of processor where data flows synchronously across array element. This project demonstrates an effective design for adaptive filter using Systolic architecture for DLMS algorithm, synthesized and simulated on Xilinx ISE Project navigator tool in very high speed integrated circuit hardware description language (VHDL) and Field Programmable Gate Arrays (FPGAs). Here, by combining the concept of pipelining and parallel processing in to the systolic architecture the computing speed increases.</p>

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