Random Access Preamble Design for High-Velocity User in Millimeter-Wave Cellular Networks

In this paper, a design technique of random access preamble (RAP) for high-velocity users (HVUs) in millimeter-wave (mmWave) cellular networks is proposed. After demonstrating the inefficiency of the conventional long-term evolution (LTE)-based RAP for HVUs in mmWave networks, linear-frequency-modulation-based RAP (LFM RAP) is proposed for the detection of HVUs. The correlation of LTE-based RAP, and ambiguity and extended-ambiguity functions of LFM RAP are analyzed to examine their properties affected by the high-velocity of the user. The performance of RAPs is evaluated through detection and false alarm probabilities in a high-velocity and multiuser environment. The results show that the LFM RAP is appropriate for HVUs in mmWave cellular networks because of its high-detection probability in a high-speed environment.