A Flexible Galileo E1 Receiver Platform for the Validation of Low Power and Rapid Acquisition Schemes

With the inclusion of 406 MHz transponders on the Galileo satellites and the new search and rescue (SAR) return link message (RLM) on the open service E1B signal, the availability of distress beacons equipped with a Galileo or combined GPS/Galileo receiver will be very important in the future to take advantage of the SAR RLM, thereby facilitating the rescue operations and helping to identify and reject false alerts. Consequently, this paper provides the status of the development of a flexible Galileo L1 receiver platform as well as an analysis and comparison of acquisition schemes suitable to be implemented in 406 MHz Cospas-Sarsat distress beacons. For each considered acquisition scheme, we compare the acquisition performance that can be obtained using GPS L1 C/A or Galileo E1B or E1C signals and consider and discuss the following main constraints: a very short time to first fix (TTFF) in cold start conditions (the beacon’s GNSS receiver may not be powered on for years before it is activated in an emergency); a low energy consumption per position fix (the beacon and GNSS receiver are battery powered); a possibly long coherent integration time to achieve synchronization and tracking in harsh environments (e.g., when some or all of the satellite signals are blocked or attenuated by an obstruction); the ability to demodulate the satellites signals in the presence of a 406MHz/5W and a 121.5MHz/(up to 100mW) beacon transmitters; and a low complexity (low price).