A Novel PSS Timing Synchronization Algorithm for Cell Search in 5G NR System

Cell search is the first step to establish downlink synchronization between user equipment (UE) and base station (BS) in the fifth generation (5G) new radio (NR) system. However, frequency offset and noise will cause a massive loss of synchronization performance. To solve this problem, a novel timing synchronization algorithm of primary synchronization signal (PSS) with anti-frequency offset and anti-noise is proposed, which includes the improved coarse synchronization algorithm based on Fourier transform and the fine synchronization algorithm based on the triple auto-correlation algorithm. The improved coarse synchronization algorithm not only has a strong frequency offset resistance, especially for large frequency offset, but also obtains the estimated frequency offset. The fine synchronization algorithm is more resistant to noise than the conventional algorithm. Finally, the algorithm analysis and simulation results show that the improved algorithm can work very well even when the normalized frequency offset increases to greater than 0.8, but the conventional algorithm fails to synchronize properly. Meanwhile, when the SNR is as low as -6dB, the detection accuracy of the timing synchronization based on the proposed fine synchronization algorithm is improved by about 31.7% compared with the conventional algorithm.