Energy-Efficient Power Control of Train–Ground mmWave Communication for High-Speed Trains

High-speed train systems have proven to be very flexible and attractive systems that can be developed under various circumstances and in different contexts and cultures. As a result, high-speed trains are widely deployed around the world. Providing more reliable and higher data rate communication services for high-speed trains has become one of the most urgent challenges. With vast amounts of spectrum available, the millimeter wave (mmWave) system is able to provide transmission rates of several gigabits per second for high-speed trains. At the same time, mmWave communication also suffers from high attenuation; thus, higher energy efficiency should be considered. This paper proposes an energy-efficient power-control scheme of train-ground mmWave communication for high-speed trains. Considering a beam switching method for efficient beam alignment, we first establish the position-prediction model, realistic direction antenna model, and receive power model. And, then we allocate the transmission power rationally by using the power minimization algorithm while ensuring the total amount of transmission data. Based on this, this paper also develops a hybrid optimization scheme and finds the limit of total energy consumption when the number of segments goes to infinity. Using simulation with various system parameters and taking velocity estimation error into account, we demonstrate the superior performance of our schemes.