Millimeter-Wave Channel Measurement Based Ray-Tracing Calibration and Analysis in Metro

In order to meet the increasing data rate demands of the onboard passengers in the metro, millimeter-wave (mmWave) wideband communication is considered as a potential candidate. In this paper, a channel measurement based ray-tracing (RT) calibration approach is employed to calibrate key parameters and reveal the reasons of the multi-path components in an inside-metro environment. The measurement was conducted in Madrid Metro with frequency ranging from 26.5 GHz to 40 GHz. By minimizing the error between the RT simulation and the measurement, the environment model and electromagnetic (EM) parameters of the related objects are calibrated. It is found that the poles and the train body can generate strong reflection and scattering components. The provided EM parameter set and the calibrated environment model will lay fundamentals to further characterize the mmWave channel and guide design of communication network inside Metro.