Radio environment map-based cognitive Doppler spread compensation algorithms for high-speed rail broadband mobile communications

Li Jinxing, Zhao, Zhao Youping

Description

Recently, there is an increasing yet challenging demand on broadband mobile communications for high-speed trains. In this article, cognitive Doppler spread compensation algorithms are proposed for high-speed rail broadband mobile communications, which make use of the dedicated radio environment map (REM) for railway to compensate the time-varying Doppler spread. The dedicated REM for high-speed rail can be viewed as a spatial-temporal database consisting of the radio channel parameters along a given railway. The performance of the proposed Doppler spread compensation algorithms are evaluated with a typical OFDM-based broadband mobile system. Simulation results show that the link-level performance of high-speed rail broadband mobile communications can be improved significantly due to the REM-enabled radio channel condition awareness and the cognitive Doppler spread compensation algorithms. The REM-based cognitive radio approach presents a new paradigm for systems design of high-speed rail broadband mobile communications.

Sujets

• Cognitive radio
• High-speed rail
• Orthogonal Frequency Division Multiplexing

Informations

• Publié par: biomed
• Publié le: 01 janvier 2012
• Nombre de lectures: 20
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Li and ZhaoEURASIP Journal on Wireless Communications and Networking2012,2012:263 http://jwcn.eurasipjournals.com/content/2012/1/263

R E S E A R C H

Open Access

Radio environment mapbased cognitive Doppler spread compensation algorithms for highspeed rail broadband mobile communications * Jinxing Li and Youping Zhao

Abstract Recently, there is an increasing yet challenging demand on broadband mobile communications for highspeed trains. In this article, cognitive Doppler spread compensation algorithms are proposed for highspeed rail broadband mobile communications, which make use of the dedicated radio environment map (REM) for railway to compensate the timevarying Doppler spread. The dedicated REM for highspeed rail can be viewed as a spatialtemporal database consisting of the radio channel parameters along a given railway. The performance of the proposed Doppler spread compensation algorithms are evaluated with a typical OFDMbased broadband mobile system. Simulation results show that the linklevel performance of highspeed rail broadband mobile communications can be improved significantly due to the REMenabled radio channel condition awareness and the cognitive Doppler spread compensation algorithms. The REMbased cognitive radio approach presents a new paradigm for systems design of highspeed rail broadband mobile communications. Keywords:Broadband mobile communication, Cognitive radio, Doppler spread compensation, Highspeed rail, OFDM, Radio environment map (REM)

Introduction Highspeed rail is a type of passenger rail transport that operates significantly faster than the normal speed of rail traffic. Specific definitions by the International Union of Railways (UIC) and European Union include 200 km/h for upgraded track and 250 km/h or faster for new track [1]. Highspeed rail receives considerable attention recently due to its costefficiency, almost allweather operation, low carbondioxide (CO 2 ) emission, and many other advan tages. In Japan, Shinkansen lines run at speeds of up to 300 km/h. In China, highspeed conventional rail lines op erate at top speeds of 350 km/h and reaches as high as 487.3 km/h during a recent test run [1,2]. Research on even higher speed train in vacuum tube is also underway in China with target operational speed of 600–1000 km/h in 10 years. Regional or international highspeed rail is under planning or construction in the United States, Europe, Asia, and South America [1]. Therefore, there is

* Correspondence: [e-mail] Institute of Broadband Wireless Mobile Communications, School of Electronics and Information Engineering, Beijing Jiaotong University, Beijing, China

an increasing yet challenging demand on broadband mo bile communications for highspeed trains, as it is neces sary to provide information (such as voice, Internet, video conference) and onboard entertainment services to passen gers, support communicationbased train control (CBTC), and transmit surveillance video and sensory data from the highspeed train to trackside base stations for the safety and efficient operation of highspeed rail. In addition, posi tive train control which has been developed in the United States is another major driver for highly reliable high speed rail broadband mobile communications. Various technologies (such as leaky cable, GSM, satellite, and 802.11 WLAN) have been employed for railway wireless communications. However, each of the abovementioned technologies has some shortcoming or limitations when applied to highspeed rail broadband mobile communica tions. The key problem associated with leaky cable is its high attenuation and high cost of deployment and main tenance; the key issue with GSMbased approach is its lim ited bandwidth and low data rate; the key problems associated with satellitebased approach are the lost of connection in tunnels, high systems cost, and significant

© 2012 Li and Zhao; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.