Joint Tracking of Delay and Frequency Offset for DSSS Systems Based on Frequency Domain Parametric Modeling

In this paper, we propose a joint delay and frequency offset tracking scheme for solving the high-performance delay and frequency tracking problem of direct sequence spread spectrum (DSSS) systems. First, we obtain the frequency domain parametric model of the received signal by delay and frequency offset compensation and frequency domain correlation, realize the parametric model dimensionality reduction by integrate and dump in frequency domain, and after that, we obtain the joint estimation of the delay error and the frequency offset error using the rooting method, and finally realize the joint tracking of the delay and the frequency offset by a feedback loop. The proposed scheme has better delay tracking performance and constant frequency offset tracking performance with limited computational complexity increase compared with the traditional dual-loop scheme based on delay-locked and frequency-locked loops. Simulation results show the advantage of the proposed scheme in terms of tracking performance and the difference in computational complexity compared to the dual-loop scheme.