On DMRS Tracking Mode Synchronization in Fifth Generation New Radio

Abstract

In this paper, we investigate the issue of tracking mode synchronization in 5G new radio based on demodulation reference signal (DMRS) as recommended by the 3rd generation partnership project (3GPP) standards. Separately performing cross-correlation of DMRS symbols for different time positions is conducted to reduce the computational complexity and estimate the value of sampling frequency offset (SFO). To achieve high accuracy, subsample offset estimation is performed based on parabolic interpolation. Performance is evaluated through computer simulations and the results show a rapid convergence of SFO estimator to the actual values and low root mean square error (RMSE) curves for different channel models. The effect of time domain SFO compensation on the performance of maximum likelihood (ML) carrier frequency offset (CFO) estimator is also evaluated in terms of the mean-squared error (MSE) as a function of signal to noise ratio (SNR).