Development of an advanced nano-satellite (VELOX-II) – ground station

• Main Author: Toh, Wen Bin
• Other Authors: Low Kay Soon
• Format: Final Year Project
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Satellite telecommunication
• Online Access: http://hdl.handle.net/10356/63827
• Institution: Nanyang Technological University

The Satellite Research Centre (SaRC) of NTU has successfully completed three satellite missions since 2011. The first satellite mission named X-SAT was a micro-satellite while the two latest satellites, VELOX-I and VELOX-PIII were launched into space in June last year belongs to nano- and pico-satellite class respectively. VELOX-II is the current nano-satellite project which is in the midst of development by the research staffs and students. It is a 12 kg communication satellite and is expected to be launched into a near equatorial orbit at an altitude of 550km above the sea level in this year. VELOX-II has a payloads of inter-satellite communication system as well as Global Positioning System (GPS) and fault tolerant electronics. The main objective of this final year project is to develop a ground station communication system using GNU Radio platform and the Software Defined Radio’s (SDR) hardware which is called Universal Software Radio Peripheral (USRP) X310 series to perform all the digital signal processing required in the project. In this project, the USRP X310 is used to detect Frequency Modulation (FM) of radio signal with the aid of GNU Radio simulation in the first task. The purpose of this experiment is to get familiar with the GNU Radio software block component’s function so that other digital signal processing tasks can be carried up more efficiently. The second task which is Upper Side Band (USB) demodulation is carried out using the USRP X310 and GNU Radio platform to demodulate any input signal to obtain an USB output. As the NTU’s VELOX-I satellite in space operate at a Very High Frequency (VHF) range of 145.98 MHz so an USB demodulated signal will contain the information that is related to our transmitted signal. Experiments are carried out to examine if the USB block diagram works for different types of signal. The experimental result for the USB block diagram testing shows that only Binary Phase-Shift Keying (BPSK) type of signal can be detected by the VELOX-I program. The last task for this final year project is to create a TCP connection between the client and server side so that a variable input frequency can be controlled at the client’s side and it will show the output result waveform in the server’s side. This objective for this experiment will allow a remote control of the input frequency from a computer with the same network ip address as the server’s ip address which will be beneficial to the ground station project. The project will test to see whether USRP X310 is able to work well with the satellite’s VELOX-I program system in NTU through an experiment testing with the USB demodulation and also to see if it is able to perform the required digital signal processing tasks. The project will also investigate if Doppler Effect of satellite in space will affect the information obtained using the USRP X310.