Feasibility Studies on the Use of Higher Frequency Bands and Beamforming Selection Scheme for High Speed Train Communication

Abstract

With increasing popularity of high speed trains and traffic forecast for future cellular networks, the need to provide improved data rates using higher frequency bands (HFBs) for train passengers is becoming crucial. In this paper, we modify the OFDM frame structure for HST, taking into account the increasing sensitivity to speed at HFBs. A lower bound on the SNR/SINR for a given rate for reliable communication was derived considering the physical layer parameters from the OFDM frame. We also analyze different pathloss models in the context of examining the required gain needed to achieve the same performance as with microwave bands. Finally, we present a time-based analogue beamforming selection approach for HST. We observed that, irrespective of the pathloss models used, the required gains are within the same range. For the same SNR/SINR at different frequency bands, the achievable data rate varies with respect to the frequency bands. Our results show the potential of the use of HFBs. However, due to the increased sensitivity of some channel parameters, a maximum frequency band of 38 GHz is suggested. Evaluation of our proposed beamforming scheme indicates a close performance to the optimal SVD scheme with a marginal rate gap of less than 2 b/s/Hz.

Higher frequency band beamforming scheme for high speed train

“…The CDT is configured based on the prior knowledge of the initial HST position and velocity. The proposed algorithm is an extension of the approach in [12]. In this algorithm, velocity estimation error and impact of BS-HST link distance are taken into account along with the introduction of a hierarchical codebook.…”

Fog Computing-Assisted Energy-Efficient Resource Allocation for High-Mobility MIMO-OFDMA Networks

“…However, providing high data rates and good quality of service (QoS) to passengers in the presence of rapidly varying channel conditions and scarce bandwidth availability is a challenging task [1]. Critical challenges have arisen from real-time communications between HSTs and fixed base stations (BS).…”