Base-band involved integrative modeling for studying the transmission characteristics of wireless link in railway environment

Dawei Li,Zheng Li,Zhan Zhang,Meie Chen,Junhong Wang

doi:10.1186/s13638-015-0316-3

Abstract

Base-band involved integrative modeling method (BIMM) is proposed for studying the transmission characteristics and bit error rate of the wireless communication, in which the transmitting and receiving antennas, wave propagation environment, and the modulation and demodulation modules are modeled and simulated integratively. Comparing with the conventional wave propagation method used in prediction of field coverage, BIMM is capable of taking the interaction between antenna and environment into consideration, and can give the time-domain waveforms of signals in different places of the wireless link, including those in the base-band modules. Therefore, the distortion reason of signal and in what place it happens can be found, and the bit error rate of the wireless communication can be analyzed. The BIMM in this paper is implemented by finite-difference time-domain (FDTD) method and is applied to the wireless link of railway communication. The effect of the electric spark generated by the power supplying network of the express train on the transmitting property and bit error rate is analyzed.

Highlights

1 Introduction With the rapid development and wide application of wireless communication, the prediction of the wave propagation and field coverage of the wireless link becomes important in characterizing the radio channel of the wireless communication, especially for the case of complicated environment, such as the railway environment
3.1 Modeling of antennas and environment In order to show the capability of band involved integrative modeling method (BIMM) in analysis of base-band signal transmission and bit rate error of wireless system, an example is given, which involves a locomotive with antenna mounted on top, two steel rails, earth plane, and a conducting wire over the locomotive for power supply
In order to find the impact of this interference on the transmitted digital signal, the generation of the electric spark and its propagation are introduced into the finite-difference time-domain (FDTD) simulation together with the RF signal

Summary

Introduction

With the rapid development and wide application of wireless communication, the prediction of the wave propagation and field coverage of the wireless link becomes important in characterizing the radio channel of the wireless communication, especially for the case of complicated environment, such as the railway environment. IMM can only deal with the RF link of the wireless system and can give the reason of distortions of RF signals. The modeling and analyzing of RF link (IMM) and base-band modules are combined together, and we call it the base-band involved integrative modeling method (BIMM). By this method, the time-domain waveform of signal at different places of the wireless link can be obtained, including those intermediate signal waveforms in base-band modules. The reason of signal distortion and in what place it happens can be found, and the bit rate error of the complete wireless link can be studied.

Problem description and method

Implementation and results

Conclusions