Design and implementation of a robust downlink communication system for nanosatellites

• Published in: 2015 International Conference on Space Science and Communication (IconSpace) pp. 164 - 169
• Main Authors: Mevada, Jagdish, Samuel, Joseph, Bhadane, Sourbh, Gulati, Akshay K., Koilpillai, R. D.
• Format: Conference Proceeding Journal Article
• Language: English
• Published: IEEE 01-08-2015
• Subjects: Amateur; Communication systems; Design engineering; Doppler compensation; Doppler effect; Frequency estimation; GNU Radio; Nanosatellite; Nanosatellites; Physical layer; Radio; Receivers; Satellite broadcasting; Satellites; Signal acquisition; Software Defined Radio; Synchronism; Synchronization; UHF
• ISSN: 2165-4301; 2165-431X
• DOI: 10.1109/IconSpace.2015.7283827

The design of a robust downlink communication system for nanosatellites in UHF amateur radio band involves many challenges like radio spectrum constraints, time-varying Doppler, clock drifts and synchronization in a LEO satellite channel. This paper presents the system designed and implemented for IITMSAT, a student satellite project at IIT Madras, which successfully overcomes these challenges using a robust physical layer design implemented on a generic Software Defined Radio platform. The performance of the proposed design is verified through simulations as well as hardware. The communication system gives a good performance which is only about 1 dB away from theory.