Galileo GIOVE-A acquisition and tracking analysis with a new unambiguous discriminator

Abstract

This paper focuses on realizing and designing an unambiguous and cost effective algorithm for tracking a Binary Offset Carrier (n,n) signal such as the BOC(1,1) Galileo signal. The aim of the Galileo receiver design is to acquire and track the E1 band BOC (1, 1) signal broadcast by the prototype Galileo satellite-GIOVE-A. Results show that it can be successfully acquired using a narrowband front end with low sampling rate utilizing conventional acquisition methods. To eliminate the effect of the ambiguous correlation function while maintaining all the features of the BOC (1, 1) spread spectrum signal, a novel non-coherent code tracking algorithm is introduced and two architectures of combining Costas loop and Delay Locked Loop (DLL) are proposed. The performances of different DLL discriminators are compared. The strength of the novel design lies in its low complexity, high robustness and lack of ambiguity with a relative high slope of discriminator function which has flexibility of choosing Early/Late spacing liked a conventional Narrow Correlator and possibility of maintaining the multipath rejection property.