Robust Random Access Preamble Detection Scheme for 5G Integrated LEO Satellite Communication Systems

In this paper, we propose a robust random access preamble detection scheme for 5G integrated low-earth-orbit (LEO) satellite. By converting the traditional frequency domain detection to time domain detection and adjusting the starting time and interval of the time domain detection window according to the large round-trip delay differences of LEO satellite systems, this scheme can directly adopt the preamble format of terrestrial 5G, and achieve the correct preamble detection and the accurate TA (Timing Advance) estimation without relying on the navigation and positioning systems, which are used to provide necessary information for TA pre-compensation based LEO satellite preamble detection scheme. In addition, the optimal detection threshold expression, which is applicable to all preamble formats, is derived from a group of threshold coefficient curves which is acquired from the estimated value of detection threshold and noise power. Simulation results show that, compared with the TA pre-compensation LEO satellite preamble detection scheme, the proposed scheme shows 1dB performance improvement at the same detection success rate under different condition of normalized carrier frequency offset (NCFO) without the help of navigation and positioning systems.