The Real-Time Simulation of Doppler Spread in Wireless Mobile Environment by RF Circuits  

作　　者：LI Zhen ZHU Xiang JI Wenli ZHENG Guoxin 

机构地区：[1]Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Shanghai University [2]Technical Center of Shanghai Shentong Metro Group Co,.Ltd

出　　处：《Chinese Journal of Electronics》2015年第4期837-843,共7页电子学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.61132003,No.61171086);LAB Opening project(No.SKLSFO2014-01)

摘　　要：The time-varying characteristic of wireless channel under the high-speed mobile environments in tunnels causes the Doppler spread to the transmitted signals,which affects the performance of wireless communication systems. The real-time Doppler effect simulation methodology directly based on Radio frequency(RF) circuits is proposed to simulate different Doppler spread effects in real environments. Mixers and a Digital-to-analog(DA)converter circuit are utilized to spread the spectrum of RF signals. A PC platform with the interface written in C#is configured to control the spectrum spread parameters.This radio channel emulator with the proposed methodology can replace the expensive fading simulating instruments with only 25.1ns system delay. Such an emulator has been applied to test the Multi-carrier wireless information local loop(McW i LL) wireless vehicle communication system in the laboratory to meet the requirement of metro Communication based train control(CBTC) system.The time-varying characteristic of wireless channel under the high-speed mobile environments in tunnels causes the Doppler spread to the transmitted signals,which affects the performance of wireless communication systems. The real-time Doppler effect simulation methodology directly based on Radio frequency(RF) circuits is proposed to simulate different Doppler spread effects in real environments. Mixers and a Digital-to-analog(DA)converter circuit are utilized to spread the spectrum of RF signals. A PC platform with the interface written in C#is configured to control the spectrum spread parameters.This radio channel emulator with the proposed methodology can replace the expensive fading simulating instruments with only 25.1ns system delay. Such an emulator has been applied to test the Multi-carrier wireless information local loop(McW i LL) wireless vehicle communication system in the laboratory to meet the requirement of metro Communication based train control(CBTC) system.

关 键 词：DOPPLER SPREAD CHANNEL simulation CIRCUITS TUNNEL 

分 类 号：TN92[电子电信—通信与信息系统]