Performance analysis on high speed railway communications with adaptive modulation and coding

Adaptive modulation and coding (AMC) transmission of wireless communications requires accurate channel state information (CSI) to select the suitable transmission mode. However, the accurate CSI is hard to be obtained for high-speed railway (HSR) communications due to the fast time-varying fading channel, which strictly limits the performance of HSR with AMC transmission. Recent studies show that the CSI can be accurately estimated utilizing ephemeral link correlation, which can enhance the performance of HSR communications with AMC transmission. In this paper, we analyze the performance of HSR communications with AMC transmission using queuing model. The joint effect of path loss resulting from train moving, shadowing effect and fast time-varying fading on AMC transmission are analyzed. The numerical results of dropping probability and throughput of HSR communication system with AMC transmission are provided, which are validated by simulation results. The effects of QoS requirements of different services of HSR on system performance are also discussed.