Effective doppler mitigation in critical satellite communications

Abstract

The modems for telemetry and telecommand applications are a key component in each satellite system: they shall guarantee reliable and effective performance during every mission phases including also critical scenarios such as the control operation of the satellite while it is placed into its orbit, the disposal of a satellite at the end of its life or the deep-space missions. In these scenarios, the link could be unstable and with a rapid variability and the communication become bursty and be characterized by poor performance. This paper introduces an alldigital implementation of a receiver, which is based on the Differential PSK (D-PSK) modulation and an enhanced version of the Digital Delay and Multiplier frequency estimator and compensator for mitigating the Doppler effect, and that results to be perfectly compliant with the aforementioned requirements. The performance of the proposed receiver is extensively studied and compared with an incoherent technique which is based on the Double Differential PSK (DD-PSK) modulation and is known to be suitable for sat-com in critical scenarios.