Directional Random Access Technique for Millimeter-Wave Cellular Systems with Multiple Antenna Arrays

The overall duration of directional random access (DRA) in millimeter-wave (mm-wave) cellular systems with directional beams is very long because preambles should be transmitted in all directions of transmit and receive beams. In this paper, two different types of DRA preambles (DRAPs; TYPE-1 and TYPE-2) are proposed for mm-wave cellular systems with multiple antenna arrays to reduce the DRA duration. The properties of the DRAPs such as the constant amplitude, correlation, false-alarm probability, and detection probability are analyzed for DRA in a multi-user environment. It is shown by simulation that the TYPE-2 DRAP is well-suited for DRA in mm-wave cellular systems with directional beams because of its high detection probability in a multi-user environment, shorter processing time, and reasonably low complexity compared with the conventional technique.