Multicarrier Tandem Spreading Multiple Access (MC-TSMA) for High-Speed Railway (HSR) Scenario

摘要

As the paradigm of the next high-speed railway (HSR) evolution, the smart railway attracts increasing attention from various professionals. With the maturity of 5G technologies, numerous intelligent applications are expected to be enabled. Therein, the Internet of Things (IoT) for railway can be supported by the massive machine-type communications (mMTCs) system. Recently, a novel multiple access scheme named tandem spreading multiple access (TSMA) has been proposed for the grant-free random access procedure in mMTC. However, high mobility has not been considered in TSMA so that it cannot be employed in IoT for railway currently. In this article, multicarrier TSMA (MC-TSMA) is introduced and the high-speed adaptability is investigated. Particularly, the impact of Doppler shift and time-varying channel is analyzed. In the meantime, the corresponding improvement designs are proposed. The simulation results show that the proposed scheme can effectively mitigate the impact of high mobility on MC-TSMA.