Energy Efficient Train-Ground mmWave Mobile Relay System for High Speed Railways

The rapid development of high-speed railways (HSRs) puts forward high requirements on the corresponding communication system. Millimeter wave (mmWave) can be a promising solution due to its wide bandwidth, narrow beams, and rich spectrum resources. However, with large number antenna elements employed, energy-efficient solutions at mmWave frequencies are in great demand. Based HSR system multiple mobile relays (MRs) top train, dynamic power-control scheme for train-ground communications is proposed. follows regular movement characteristics trains considers three phases train movement: enters cell, all MRs covered leaves cell. transmit power further refined according cell distance between remote radio head. By minimizing energy consumption under constraints transmitted data budget, allocated through multiplier punitive function-based algorithm. Comprehensive simulation results, where velocity estimation error taken into account, provided demonstrate effectiveness proposed over several baseline schemes.