Enhancement of GPS signals acquisition in non-homogeneous environment using CFAR techniques

This article discusses the adaptive acquisition process analysis performed by a Global Navigation Satellite System (GNSS) receiver. Signal acquisition determines the presence or absence of a GNSS signal by comparing the tested signal to an adaptive threshold. The main objective of this work is to find the thresholding that realizes a constant false alarm rate (CFAR) in both Ordered Statistics CFAR (OS-CFAR) and Censored Mean Level Detector CFAR (CMLD-CFAR), in Rayleigh Fading Channel. In GNSS acquisition, pilot and data channels may have different thresholds. Therefore, two scale factors (T
1
and T
2
) for each detector using the "AND" and "OR" fusion rules must be calculated. Simulation results demonstrate that the use of CMLD-CFAR detector is the best way to improve detection performances in non-homogeneous environment of the GPS (Global positioning system).