Filter-Bank Based Technique for Fast Acquisition of Galileo and GPS Signals

The computational load and the speed of the code acquisition process of any CDMA system depend on the number of timing hypotheses required to search a given uncertainty window (i.e., the code epoch interval in GPS and Galileo systems). By increasing the spacing between the timing hypotheses (or the time-bin step), this computational load may be reduced and the acquisition speed may be increased. However, the time-bin step is limited by the main lobe width of the correlation function envelope (i.e., the correlation which is performed between the incoming signal and a reference code stored at the receiver). If the width of this main lobe is increased, the time-bin step may be increased as well. Here, a filter-bank based method is proposed, which allows the use of higher time-bin steps than those usually used in GPS/Galileo and, thus, it has the potential of increasing the acquisition speed. Simulation results are shown in comparison with other acquisition methods