3GPP standardization activities in relay based 5G high speed train scenarios for the SHF band

Activities related to the 3GPP high speed train (HST) scenario in the super high frequency (SHF) band are described in this paper. Communication between an onboard relay station and remote radio head placed along the railway is considered in the scenario. The content of the paper focuses on motivations for considering the scenario in 3GPP, descriptions of the HST channel model, proposed new radio (NR) technologies and evaluation results. The design elements considered in the evaluation include frame format, numerology, synchronization mechanism, reference signal design and waveform.