Coexistence of Downlink High-Speed Railway Communication System with TDD-LTE Cellular Communication System

With the deployment and development of high-speed railway in the world, the corresponding research on high-speed railway communication technology has made great progress. Generally, the dedicated high-speed railway communication network is believed to be required to meet the demand of high data rate with QoS guarantee on this high-speed scenario. The long term evolution (LTE), supporting the speed of 500 km/h as well as throughput of 50M to 100M bps, has a great advantage in high-speed railway communication scenario. However, little or none of the previous research involves the aspects of coexistence between the dedicated high-speed railway communication system and the adjacent cellular network systems along the railway. Thus, in this paper, we first introduce the high-speed railway communication system as well as propose a model of it, and then evaluate its coexistence performance with macro cellular communication system based on this model. Our research results show that, when these two network systems are deployed on the same frequency band, or when macro cellular system is densely deployed in urban areas, the high-speed railway communication system will be severely affected by the inter- system interference, and additional isolation will then be needed in these cases.