Research of weak signal acquisition algorithms for high sensitivity GPS receivers

Weak signal acquisition has been a limiting factor for high sensitivity GPS receiver. This paper presents GPS signal acquisition algorithms: coherent integration (COH), noncoherent integration (NCOH), and differential coherent integration (DFC) with detailed analysis. Numerical simulations demonstrate that DFC is a superior approach than NCOH in weak GPS signal detection. DFC improves acquisition sensitivity by approximate 1.9dB, 0.8dB than its counterpart NCOH without and with 100Hz carrier Doppler shift as the probability of false alarm is fixed to 0.1% and the probability of detection setting to 90%. In addition, DFC decreases mean acquisition time by about three times than NCOH under the same simulation conditions.

[1]  Christophe Macabiau,et al.  Analysis of a software-based A-GPS acquisition performance using statistical processes , 2005 .

[2]  Gérard Lachapelle,et al.  GPS Software Receiver Enhancements for Indoor Use , 2005 .

[3]  T. Haddrell,et al.  Understanding The Indoor GPS Signal , 2001 .

[4]  U. Dettmar,et al.  Efficient differentially coherent code/Doppler acquisition of weak GPS signals , 2004, Eighth IEEE International Symposium on Spread Spectrum Techniques and Applications - Programme and Book of Abstracts (IEEE Cat. No.04TH8738).

[5]  J. Holmes,et al.  Acquisition Time Performance of PN Spread-Spectrum Systems , 1977, IEEE Trans. Commun..

[6]  G. Lachapelle,et al.  Enhanced Differential Detection Scheme for Weak GPS Signal Acquisition , 2007 .

[7]  James B. Y. Tsui,et al.  Fundamentals of global positioning system receivers : a software approach , 2004 .

[8]  Steffen Schön,et al.  On the capability of high sensitivity GPS for precise indoor positioning , 2008, 2008 5th Workshop on Positioning, Navigation and Communication.

[9]  Bo Zheng,et al.  Differential combining for acquiring weak GPS signals , 2007, Signal Process..

[10]  Elvino S. Sousa,et al.  A differentially coherent PN code acquisition receiver for CDMA systems , 1997, IEEE Trans. Commun..

[11]  P. W. Ward,et al.  GPS receiver search techniques , 1996, Proceedings of Position, Location and Navigation Symposium - PLANS '96.