Abstract:
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This document presents a study about the Radio beacon synchronization in coherent receivers for nanosatellite applications. First of all, it is studied the history of these nanosatellites and their actual role in the Aerospace industry, considering their low cost compared to bigger satellites and also because of their availability for all types of companies and people (as universities). These nanosatellites have a wide range of applications, and lots of them depend on the imagination of the user, but one of the most remarkable application is a constellation of these nanosatellites that could give internet access to the whole world. One of the objectives of this Project is to create a ground station, this means to create a high efficient receiver capable of receiving a big volume of data from a nanosatellite, while the nanosatellite is overflying the ground station. In order to optimise this process it is needed synchronization in phase and frequency of the receiver oscillators with the transmitter, guaranteeing a coherent transmission of the obtained data from the payload. For that, nanosatellites emit a radio beacon useful both for the pointing of the ground station and the synchronization of the receiver oscillators. Therefore, this Project will try to study the synchronization of the receiver local oscillators with the radio beacon emitted by the satellite, focusing on the Phase Locked Loop (PLL) system, and also observing the problems that this type of transmission has, as the Ionosphere or Doppler effects. To do that, a Laboratory test and another one using the tool Simulink from Matlab will be done. |