Application Research On MIMO Technology In The GSM-R High Speed Railway Communication

GSM-R(GSM for Railways) system, as a new railway wireless communication network and a platform which transforming dispatching orders and control information, its reliability is becoming a research of concern. Now the engineering design could only meet the basic requirement of network coverage. According to the test result of several new test lines, the multi-path effect caused by the high train speed and complicated variable geography condition, seriously affected the communication quality which is still far from the reliability requirement of signal transforming. To deal with these problems, MIMO (Multiple-input-multiple-output) technology can be applied to improve the communication quality.MIMO is a new technology in the communication domain, which can increase the capability and Spectrum efficiency significantly without extra bandwidth and power cost. MIMO can change the distribution of receiving signal, reduce the probability of deep fading, and greatly increase the cover rate, decrease the transforming power and also lower the SER(symbol error rate). A configuration of Multiple-input-multiple-output on the base station side may improve the performance in existing system and it is feasible whether on maneuverability or cost.It is certified by this dissertation that, using MIMO in the railway wireless communication system can improve the communication quality and fit the characteristic of high speed railway communication. Because of the fast moving of train, the wireless channel varies quickly, which could lower the relevance of the receiving signal from different antenna, leading to higher cover rate and less construction cost. Considering the limitation of the experiment, the computer simulation and the simulation platform of MATLAB-SIMULINK is adopted, a model of multi-antenna communication system with the max speed of 300km/h was constructed, using time-variable Rayleigh multi-path channel. Different system performance was simulated and analyzed under different number of antennas, different modulation mode and different speed in order to approve the priority of applying MIMO in GSM-R system.