This paper addresses the signal acquisition problem in the presence of interferences using antenna arrays in the general framework of Global Navigation Satellite Systems receivers. We describe and compare two different approaches: the first one is based on the generalized likelihood ratio test (GLRT) detector directly applied on the array snapshots, and the second one uses a digital beamformer as a spatial filter to mitigate the interferences and acquire the signal using the beamformer output. We show that the array-based GLRT acquisition is equivalent to a conventional acquisition based on the output of a time reference beamformer. The test statistics of the techniques are analyzed in terms of the probability of detection and false alarm. Monte Carlo simulations using the Galileo E1 signal structure support the theoretical results, even when the array is moderately uncalibrated.
Preface. Preface to the First Edition. Chapter 1. Introduction. Chapter 2. Basic GPS Concept. Chapter 3. Satellite Constellation. Chapter 4. Earth-Centered, Earth-Fixed Coordinate System. Chapter 5. GPS C/A Code Signal Structure. Chapter 6. Receiver Hardware Considerations. Chapter 7. Acquisition of GPSb C/A Code Signals. Chapter 8. Tracking GPS Signals. Chapter 9. GPS Software Receivers. Chapter 10. Acquisition of Weak Signals. Chapter 11. Tracking Weak Signals. Chapter 12. GPS Receiver-Related Subjects. Index.
This study compares the performance of a 3-h dipstick trehalose test with GLABRATA RTT, a new commercially available 20-min test for the rapid identification of Candida glabrata. With the exception of blood agar, GLABRATA RTT gave reliable results with all media tested and was always superior to the dipstick test.