Optimization of 4G wireless access network features by using reverberation chambers: Application to high-speed train LTE users

A real 4G base station connected to live network of Telecom Italia and radiating into a reverberation chamber is used to investigate performances of fast moving terminals on board of high-speed trains. The results concern a testing campaign by replicating real high speed train propagation scenarios, like the train running in open space or in tunnels, with the aid of a reverberation chamber. This is partially filled by absorbing materials in order to approach the multipath propagation that is typical of a train coach, and equipped with two rotating paddels in order to replicate the signal fluctuations that are typical for the mentioned environments. The effects of Doppler shift and its fast variations are presented, together with an analysis of the efficiency of different transmission solutions for tunnels.