Locating Interfering Sources By Time-domain Characteristic Of GSM-R

GSM-R(Global System Mobile for Railway) is based on GSM, which is the most populate and mature wireless communication system in the world. GSM-R has been decided to be the future wireless communication network for railway in China, so for optimizing the communication system, making the total network safer and improving the efficiency of our railway, we should design some relate devices to find out the disturbing singles that aren't from GSM-R system. . Managing these difficulties to make the network cleaner, we'll get a safer wireless communication system for railway—GSM-R.Conventional disturbance-locating system is generally based on a spectrum analyzer. Mixed singles will be analyzed in frequency-domain and disturbing singles will be extracted from mixed singles by using a spectrum analyzer and an antenna with a good direction, which is fixed in an automobile .Meanwhile, modify the directions of disturbing sources, and finally get the locations in detail of the disturbances. This process is very simple and correct, however, testing devices are very heavy and expensive and operators correlatively should do much work. To improve these limitations, we'll bring forward a new method, managing the singles in time-domain, to locate disturbing sources.Locating the disturbing sources in time-domain mainly fixes the mixed singles received and outputs available singles whose frequency approximately is zero. Then judge if or not any disturbance exits directly by a computer. Design a testing software based on the time-slot characteristic and multi-frame of GSM-R to make the testing computer get the working frequency and time-slot as soon as possible, then the testing system can tell you if some disturbing singles exist real-timely .Do the same work as above, finally the computer will get the disturbing sources in detail by using an GPS (global position system).During this process, the key to manage difficulties is to get singles of integrated time-slots exactly. All these need to be familiar with the wireless interface, time-slot characteristic and multi-frame of GSM-R and make judgment real-timely of various logical channels, such as FCCH, TCH, etc. Besides it should be chosen the testing electromagnetic environment on the spot and correct radiating models to get the disturbing sources.