5G New Radio Physical Random Access Preamble Design

To cope with the stringent requirements imposed on the random access (RA) procedure by the use cases envisioned for 5G NR, we propose an RA preamble design based on cyclically delay-Doppler shifted m-sequences. In contrast to the legacy 4G LTE RA preambles based on Zadoff-Chu (ZC) sequences, the proposed design is very robust against frequency uncertainties originating from wireless channel propagation and local oscillator imperfections. Simulation results show that the proposed m-sequence based preambles deliver good performance even under harsh transmission conditions, while ZC based preambles fail. Further advantages of adopting m-sequence based preambles in 5G NR include random access channel (RACH) capacity enhancement, support for low-power devices and low complexity implementation.