Multipath Mitigation in a Galileo SOL Receiver

Abstract

The potential of the SAGE (Space-Alternating Generalized Expectation Maximisation) algorithm for Galileo Safety-of-Life (SoL) navigation systems in order to distinguish the line-of-sight signal (LOSS) is to be considered. The SAGE algorithm is a low-complexity generalization of the EM (Expectation-Maximisation) algorithm, which iteratively approximates the maximum likelihood estimator (MLE) and has been successfully applied for parameter estimation (relative delay, incident azimuth, incident elevation, Doppler frequency, and complex amplitude of impinging waves) in mobile radio environments. This study discusses receivers using a single antenna. Whereas we estimate the complex amplitudes and relative delays of the impinging waves. The results of the performed computer simulations and discussion indicate that the SAGE algorithm has the potential to be a very powerful method to successfully estimate parameters of impinging waves for Galileo SoL navigation systems. SAGE has proven to be a promising method to combat multipath for safety critical navigation applications due to its good performance, fast convergence, and low complexity.