Impact of Imperfect Channel Estimation on 5G-NR

Abstract

In 5G new radio (5G-NR), newly defined channel state information reference signal (CSI-RS) and demodulated reference signal (DMRS) are used together in the front-load transmission to improve the performance of channel estimation for the Physical Downlink Shared Channel (PDSCH). 5G-NR PDSCH first uses CSI-RS to determine precoder matrix together with the true beam specifications, then DMRS decides on the channel coefficients for the PDSCH. In this work, the effect of the imperfect channel estimation is elaborated in CSI-RS and DMRS channels separately. Our simulation results suggest that the imperfect estimation of DMRS channels affect the coded block error rate (BLER) of realistic channel models significantly. We also compare and analyze simulation results for both Clustered Delay Line (CDL) and Tapped Delay Line (TDL) channel models.