Detection Probability of PRACH Preamble for NR in 3GPP TDL Channel Models

Abstract

This paper presents the preamble detection probability for the Physical Random Access Channel (PRACH) with a long sequence based on the New Radio (NR) radio interface for five Tapped Delay Line (TDL) channel models by the 3rd generation partnership project (3GPP). Computer simulation results validate the PRACH detection probabilities of three non-line-of-sight (NLOS) and two LOS TDL channel models from the features of the respective power delay profiles. We show that PRACH Format 1 achieves a higher PRACH detection probability than that for Format 0 due to the repetition effect of the preamble sequence in a very low average received signal-to-noise (SNR) region. We also show that PRACH Formats 2 and 3 decrease the required average received SNR that satisfies the target PRACH detection probability by approximately 4.5 dB - 5.0 dB compared to that for Format 0. Finally, we show that when multiple PRACHs are transmitted simultaneously allowing contention, the impact of the cross-correlation among the PRACHs is low and that a high PRACH detection probability is achieved even in a low average received SNR region.