Research On Radio Wave Coverage And Field Strength On Boundary Of GSM-R

In the rail traffic control, Wireless communication platform is an important base to administer the operation of train and organize the transport. With the rapid progress of mobile communication, dedicated communication system for railway--GSM-R plays a more and more important role in the development of the railway, and is becoming the derection of the railway communicationAccording with the current situation of China, the paper deeply researches and simulates the loss of air path, coverage radius and overlap coverage, as well as field strength on boundary under the multiple frequency , which is between GSM-R and GSM in term of space.Based on Hata model, with considering the speed and train control factors, a reasonable arithmetic of coverage radius is proposed, and the relation between the train speed and the overlap coverage is researched. By means of handover time, handover margin, coverage radius and so on, the length of overlap coverage in five typical railway environments are calculated, and the performance is analyzed too. The simulated curves and analysis indicate that it is useful and effective.Following the character of the frequency reuse according to space specially for Chinese railway, the model of the field strength on boundary is built, and the scheme of calculating the GSM-R interference signal from GSM base station is proposed. The model includes the affect of GSM-R and GSM base station to the train, then the transmit power of GSM base station, the strength of interference signal and the strength of useful signal are computed. At last, the C/I is given and the factors that impact the C/I are analyzed, and the reasonable field strength on boundary is suggested.