Study of outdoor signal coverage and network convergence of TD-LTE and TD-SCDMA in high-speed railway

This paper mainly introduces some related problems about special mobile communication signal based on TD-LTE and TD-SCDMA in high-speed railway, summaries the main difficulty of TD-LTE coverage in high-speed railway and analyses TD & LTE wireless network coverage characteristics and key technologies under the environment of high-speed railway. First, we make a contrast of the coverage range of TD & LTE uplink and downlink in ordinary situations. Then we calculate the 2G/3G/4G overlapping coverage lengths. Finally, we consider effective cover radius, the distance and grazing angle between stations and railway in 2G/3G/4G networks, calculate different distance between stations. The result shows that distance between stations is limited by LTE on sharing station address. Using single RRH with two antennas, the antenna height is 30 m, and the speed of the train is 250 KM/h, the RRH distance among different cells can be 1177 m, and the RRH distance among same cells can be 1311 m. As the reference of network planning, construction and optimizing, the coverage radius and station spacing in different standards calculated by this article will improve user perception and promote the brand value of China Mobile network.