MmWave extra-large-scale MIMO based active user detection and channel estimation for high-speed railway communications
The current High-Speed Railway (HSR) communications increasingly fail to satisfy the massive access services of numerous user Nail Tools equipment brought by the increasing number of people traveling by HSRs.To this end, this paper investigates millimeter-Wave (mmWave) extra-large scale (XL)-MIMO-based massive Internet-of-Things (IoT) access in nea