Acquisition of PN sequences for digital DS/BPSK navigation receiver

A digital PN sequences acquisition system was proposed to solve the long PN sequences acquisition problem in a radio navigation system. In the process of searching for PN sequences phase, a serialparallel combined acquisition scheme was adopted in the system proposed , and Tong algorithm,a multiple dwell serial search algorithm,was adopted. Based on the established mathematics model, the relations between the signal-noise ratios, the probability of false alarm, the probability of detection and the searching rate were analyzed. A way used to determine the locking threshold and the losing locking threshold was introduced. According to the result of the analysis, the designed digital code acquisition system has higher probability of detection, lower probability of false alarm and shorter average acquisition time.