Research On Detection And Location Of GSM-R Interference Source For Railway Radio Communication

Currently,GSM communication system is widely used as mobile communication standards.GSM communication system has been developed into a very mature communication standard through a large user base and a long commercial time.For this reason,in 1993,the International Union of Railways(UIC)and European Telecommunications Standards Institute(ETSI)made a decision that new generation railway wireless communication system would adopt GSM-R communication system based on GSM Phrase 2+ specification in various countries of Europe.In 2000,Ministry of Railways of the People's Republic of China made a decision that GSM-R communication system would gradually replace the old railway communication system.GSM-R communication system provides communication support for railway transportation.Special application of GSM-R has very high requirements on the safety of communication.Base on this,this paper studies the interference detection,interference suppression and location of interference target.The main contribution of this paper list as follow:(1)In this paper,CRLBs of considering the Doppler shift and not considering the Doppler shift are derived respectively;aiming at the problem of high Doppler frequency shift caused by high-speed railway movement,the influence of Doppler shift on positioning accuracy is analyzed and a conclusion is achieved that Doppler shift has no effect on RSS positioning accuracy when the positioning target's speed is less than 500Km/h.Based on the WINNER-II path loss model,the system frequency is the key parameter of path loss.RSS localization algorithm will have different positioning result with the change of path loss information.This paper study the effect of Doppler shift on the positioning accuracy based on the WINNER-II model.(2)In this paper,a method of interference detection,interference target localization and interference suppression program is designed;meanwhile,the effectiveness of the program is verified by simulation.To determine whether there is interference in GSM-R communication system,this paper researches the interference detection based on traffic statistics and field test.Aiming at the eradication of interference and interference suppression,position of interference target is needed.To estimate interference target location information,in this paper,an interference target location algorithm is proposed based on array signal processing technology,MUSIC spectral estimation technology and dual BS station AOA location algorithm.After interference detection,in order to guarantee the normal operation of the communication system,this paper adopts the array signal processing technology to suppress the signal from the direction of interference signal.(3)In this paper,an RSS localization algorithm with closed solution is proposed,and the corresponding random CRLB is deduced.In view of the advantage of RSS,meanwhile,this paper proposes the RSS positioning algorithm which is different from the previous positioning algorithm based on array signal processing.The proposed algorithm doesn't need hardware support of the array antenna.The transmit power and the path loss exponent are the key parameters of the RSS localization algorithm.In this paper,an RSS localization algorithm based on two-step weighted least squares is proposed for the case that the transmit power and the pass loss exponent are constant.Considering that the interference source of railway communication is non cooperative communication,the transmitting power is often unknown.For the case that the transmit power and the pass loss exponent are unknown,the transmit power is treat as an unknown parameter,and the pass loss exponent is modeled as a random number of Gaussian distribution.An RSS localization algorithm with closed solution is given and corresponding random CRLB is also given.