Title :
Improved fast modified double-block zero-padding (FMDBZP) algorithm for weak GPS signal acquisition
Author :
Wen Zhang ; Ghogho, Mounir
Author_Institution :
Coll. of Opto-Electron. Sci. & Eng., Nat. Univ. of Defense Technol., Changsha, China
Abstract :
Acquisition of weak GPS signals requires long Predetection, Integration Time (PIT). The double-block zero-padding (DBZP) algorithm can use long PIT without any assisting information to acquire weak GPS signals. Modified double-block zero-padding (MDBZP) algorithm accounts for the Doppler effect on the code duration. It also develops the Doppler frequency bin elimination method during the noncoherent integration steps. The fast modified double-block zero-padding (FMDBZP) algorithm based on MDBZP algorithm eliminates the redundant FFT computations by considering possible data bit combinations and bit edge positions. Although the computation burden of FMDBZP is lower than that of MDBZP, it may still be very heavy. This paper aims to reduce the computation complexity and save memory space further. Three methods are introduced to improve the FMD-BZP algorithm. One consists of unlikely data bit combination path elimination during coherent integration steps. The second one perform unlikely code phase elimination during noncoherent integration steps. The third one perform unlikely bit edge elimination also during noncoherent integration steps. The good performance of the proposed improved FMDBZP algorithm is illustrated using both simulation and real data.
Keywords :
Doppler effect; Global Positioning System; computational complexity; fast Fourier transforms; signal detection; Doppler effect; Doppler frequency bin elimination; FMDBZP algorithm; GPS signal acquisition; code duration; computation complexity; data bit combination; fast modified double-block zero-padding algorithm; noncoherent integration; path elimination; redundant FFT computations; weak GPS signals; Complexity theory; Correlation; Doppler effect; Global Positioning System; Niobium; Satellites; Signal processing algorithms;
Conference_Titel :
Signal Processing Conference, 2010 18th European
Conference_Location :
Aalborg