Symmetric Phase-Only Matched Filter (SPOMF) for Frequency-Domain Software GNSS Receivers (Postprint); Conference paper, 8 Apr 2005-8 Sep 2006

摘要

As a powerful tool, the symmetric phase-only matched filter (SPOMF) has been shown to yield superior performance over the conventional correlator and is widely used in image registration and recognition. In this paper, we investigate the use of this SPOMF for processing GNSS signals. This extension is compatible with our frequency-domain software GNSS receiver architecture in which both the incoming signal and replica spectra are available for the SPOMF implementation versus the conventional correlator. The use of phase-only information is equivalent to equalizing the magnitude spectrum in contrast to the original spectrum that tapers off according to a sinc-function. This tends to accentuate the high frequency components corresponding to edges or transitions in the signals. As such, the SPOMF produces a much sharper peak (ideally a Dirac delta function) that is more accurate in timing and less sensitive to multipath. In addition, the same operation is applicable to both a binary phase shift keying (BPSK) modulated signal such as the GPS C/A-code and P-code and a binary offset carrier (BOC) modulation such as the GPS M-code and Galileo codes. More importantly, it only has a single matching peak regardless of which modulation code is being used. In this paper, the SPOMF is introduced within the framework of a generalized frequency-domain correlator (GFDC) for GNSS signals. The salient features of SPOMF as well as its application to BPSK and BOC signals are illustrated with simulation examples.