Improving Acquisition of Weak GPS Signals using Fuzzy Logic based Wavelet Transform

The acquisition process is one of the main steps in the GPS receiver, in which the search for satellites in view and providing an initial estimate of the code phase and the Doppler shift are carried out. In conditions where the signal-to-noise ratio is low, the performance of this block suffers serious disturbances. In this paper, a method based on wavelet transform along with a type II fuzzy system is proposed to increase the receiver's ability to acquire weak GPS signals based on which more satellites can be acquired without increasing the integration time. Subsequently, more information is provided to carry out the next steps of the positioning process using GPS receivers. The simulation results show that the proposed method improves the receiver's ability to acquire weak signals compared to conventional methods.