New solutions to reduce the time-to-CED and to improve the CED robustness of the Galileo I/NAV message

In the current framework of Galileo and thanks to the flexibility of the I/NAV message, introducing new pages in order to propose an optimization of the E1-B Galileo signal has been proposed [1]. This optimization process pursues two different objectives. The first objective aims to reduce the Time To First Fix (TTFF), achieved by shortening the time to retrieve the Clock and Ephemerides Data (CED). The second objective aims to improve the resilience and robustness of the CED, particularly under hostile environments. Under the backward compatibility precondition, new outer channel error correction solutions for Galileo I/NAV are proposed in this paper. Especially, a new family of codes called Lowest Density Maximum Distance Separable codes (LD-MDS) is proposed to be used in this paper, thus in GNSS context. This family of codes, along with an enhanced performance decoding method based on the use of a soft serial iterative decoding, provides an optimal solution in order to reduce the TTFF as well as to improve the robustness of the CED.