High Dynamic Pseudo-Random Code Tracking Using Unscented Kalman Filter and Carrier-Aiding Technology

In high dynamic direct-sequence spread-spectrum (DS/SS) systems, due to the impact of Doppler shift on Pseudorandom (PN) code rate, it´s very hard to measure PN code delay accurately. In this paper, a new PN code tracking method is proposed to address this issue. Unscented Kalman Filter (UKF) is employed to estimate carrier phase and frequency, and the carrier phase variation is used to aid the code tracking loop to remove most of the incoming dynamics. The loop bandwidth can be significantly narrowed to guarantee the code delay measurement precision and the dynamic tracking performance is improved. Simulations show that the method is feasible.