Study Of Inter-modulation Interference In GSM-R System

System of GSM-R is based on the world’s most mature and common public wirelesscommunication system. It is a wireless communication system designed to meet the GSMrailway applications. However, due to the electromagnetic environment of GSM-R wirelesscommunications system, wireless transmission process is inevitably disturbed by variousnoise, so channel interference of GSM-R system for mobile communications is very large.Interference will certainly cause communication quality, increase call troubleshooting, greatlyreduce the efficiency and speed of the spectrum. As a special railway mobile communicationsystem, Its safety and efficiency is directly related to the development of China’s railwaybusiness and the national economy, so GSM-R system require higher reliability in order toprotect the safe operation of trains. Intermodulation interference effects of GSM-R system is amajor safety hazard, and the present to solve intermodulation interference methods have theirlimitations. Work of this paper is to improve the existing algorithm. The main work is asfollows:(1) Analyse GSM-R system, introduce the reason of inter modulation interference. Andthe solution of inter modulation interference in GSM system is introduced. Analyse the linearpower amplifier, introduces power amplifier linearization technology at present.(2) Analyse pre-distortion linearization technology, the paper mainly study pre-distortionlinearization technique, it is stable, high accuracy and suitable for broadband communications.It is an important means of amplifier linearization, in this paper, based on the existingalgorithm, then I put forward a new algorithm. The convergence rate is higher, better stabilityand the amount of calculation is relatively small. Then test the new algorithm.(3) Build a path loss model of GSM-R system. Then introduce the traditionaloptimization methods. Last, compares the optimization algorithm based on frequencyplanning. Last, as the full text of the summary, conclusions and innovation of this thesis, andprospects for future research work. At the same time, give the further research andimprovement.