Performance Comparison of Different Correlation Techniques for the AltBOC Modulation in Multipath Environments

In this paper, different correlation techniques (narrow correlator, double delta correlator and subcarrier processing) that can be applied to the new Galileo alternate binary offset carrier AltBOC(15,10) modulation are discussed with respect to their functionality, implementation, and multipath mitigation performance. Moreover, effects of the receiver parameters (precorrelation bandwidth, spacing between correlators) on the ranging errors are also presented. The performance of the multipath mitigation concepts is illustrated in 2D and 3D multipath error envelopes assuming multipath scenarios with one and two multipath components and constant signal attenuation factors. The main purpose of this paper is to provide a better understanding of the performance of the AltBOC modulation and the effect of multipath on code and carrier measurements for different multipath environments, and thus help the receiver designers to select the best correlation technique for their particular applications.