Exploiting the forecast channels for power allocation in High-Speed Railway communications

A High-Speed Railway (HSR) communication system also has its own advantages compared to a conventional cellular system due to the fixed railway infrastructure and a priori known position of the trains. Based on the measurement results and analysis regarding the propagation channels for HSR communications in literature, this paper distinguishes and analyses the permanent and temporary elements affecting the channels. The characteristics of the channel at the positions when the train will pass in a short time (called here “future” channel) can be forecast based on the permanent elements and therefore provide a novel method to minimize the total transmit power and range for transmitting uplink packets with a certain time-to-live (TTL) period. A power reduction up to 20 dB can be achieved for packets with TTL period of 200ms.