摘要
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<E uplink and downlink in ordinary and special situations. Then we consider effective cover radius, the distance and grazing angle between stations and railway in 2G/3G/4G networks, calculate different distance between stations. Last, we did capacity planning for TD & LTE as telephone traffic throughput required in high-speed railway. 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 30m, 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. In the tunnel scene, the leakage cable cover is used and the station space distance of TD & LTE is 0.5 km. Tunnel station should move the switch belt to outdoors as much as possible without switching. This paper finished the link budget, protection distance measurement of cells and study of coverage method in the tunnel scene. The result helps guiding in planning, designing and optimizing for high-speed railway network in reality.
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<E uplink and downlink in ordinary and special situations. Then we consider effective cover radius, the distance and grazing angle between stations and railway in 2G/3G/4G networks, calculate different distance between stations. Last, we did capacity planning for TD & LTE as telephone traffic throughput required in high-speed railway. 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 30m, 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. In the tunnel scene, the leakage cable cover is used and the station space distance of TD & LTE is 0.5 km. Tunnel station should move the switch belt to outdoors as much as possible without switching. This paper finished the link budget, protection distance measurement of cells and study of coverage method in the tunnel scene. The result helps guiding in planning, designing and optimizing for high-speed railway network in reality.
