Pulse Position Detection of the Pseudo Random Time-Hopping Pseudolite for the Participative GNSS Receivers

The pulse position detection of the pseudorandom time-hopping (TH) pseudolite is critical for the participative global navigation satellite system (GNSS) receivers. The conventional method to detect the pseudorandom TH pulse positions of the received pseudolite signal is mainly based on the exhaustive search of the matched TH intervals, which may cause low detection probability or even detection failure in relatively low signal to noise ratio (SNR) environments. With this problem, a new method to detect the TH pulse positions is given. The general process of the given method is that first the TH intervals derived from the correlation peaks of discontinuous direct sequence spread spectrum (DSSS) component are mapped to a code sequence, and then the mapped code sequence is circularly correlated in turn with each code sequence obtained from each group of TH slot indices of the TH table, finally by searching the maximum circular correlation peak, the TH slot indices of the received pseudolite signal and their initial phase will be found, further by combining them the work of TH pulse position detection is fulfilled. The simulation results show that with the given method, the detection probability and detection error of the obtained TH pulse positions can be greatly improved, hence the performance of the participative GNSS receivers will be enhanced.