Fast Acquisition in GPS Receivers using Sub-Frequency Bands

Each software Global Positioning System (GPS) receiver consists of three sections called acquisition, tracking, and navigation. The acquisition section is known as the first part of the receiver that has some serious problems to increase the speed of acquiring the GPS signals. In some cases, the Doppler Effect (DE) that causes the relative motion between satellite and receiver leads to transforming the carrier frequency of the GPS receiver. In this study, we propose new method to achieve fast acquisition in GPS receivers. In our presented method, the Doppler frequency band has a deviation of ; so that it has been considered in the worst case. In the proposed method, we limit the frequency band by using a smaller filter and then completely cover the space of by shifting the filter. In each shift, the satellites in Line of Sight (LOS) are detected and separated from the collection list of satellites. In this method, the best filter that reduces the acquisition time is selected. To validate proposed method, we utilize five real datasets that two of them were collected from around Iran University of Science and Technology. The experimental results represent that our suggested method outperforms the conventional band-fixed method in terms of the execution time and computational complexity by approximately 22% and 19%, respectively.