PRACH Transmission Employing Carrier Frequency Offset Pre-Compensation Based on Measurement at UE for NR Uplink

Abstract

This paper proposes physical random access channel (PRACH) transmission employing carrier frequency offset (CFO) pre-compensation that is measured at a set of user equipment (UE) using the synchronization signal block for the New Radio uplink. Computer simulation results show that by using cyclic-prefix (CP)-based fractional-frequency offset (FFO) estimation and joint integer-frequency offset (IFO) estimation with the primary synchronization signal, the correct FFO and IFO estimation probabilities of 90% are achieved at the average received signal-to-noise ratio (SNR) of approximately -4 dB and -8 dB, respectively, at a UE receiver. Accordingly, we show that when the average received SNR at the UE receiver is higher than approximately -5 dB, the miss-detection probability (MDP) of the proposed PRACH transmission with CFO compensation at UE transmission is almost identical to that without CFO. We also show that the PRACH transmission with CFO compensation at UE transmission achieves almost the same PRACH MDP as that without CFO for the frequency stability of a UE local oscillator of up to 10 ppm when the average received SNR at the UE receiver is higher than approximately 0 dB.