Radiation Mode Simulation for Simultaneous Operation of Spread Spectrum and Phase Modulated Telemetry Downlinks of Co-located GEO Spacecrafts

Authors

  • Kosuru Sai Malleswar U R Rao Satellite Centre, Bengaluru, Karnataka
  • Himani BS U R Rao Satellite Centre, Bengaluru, Karnataka
  • Khan Afzaal U R Rao Satellite Centre, Bengaluru, Karnataka
  • Sirshendu Das U R Rao Satellite Centre, Bengaluru, Karnataka
  • Suman R. Valke U R Rao Satellite Centre, Bengaluru, Karnataka
  • Senthil Kumar V. U R Rao Satellite Centre, Bengaluru, Karnataka
  • Ramalakshmi N. U R Rao Satellite Centre, Bengaluru, Karnataka

DOI:

https://doi.org/10.46610/JoECS.2023.v08i03.001

Keywords:

Anechoic chamber, Code Division Multiple Access (CDMA), Demodulator, Interference, Phase modulation, Telemetry

Abstract

Transmission of telemetry data to the ground station is critical for all spacecraft missions. The allocated spectrum for Telemetry downlinks of GEO spacecraft has been overcrowded in recent years due to a steady increase in the number of GEO missions. Implementation of Code Division Multiple Access (CDMA) systems in the same bandwidth is proposed as a solution to overcome this problem. To prove the compatibility of the proposed scheme with existing telemetry downlinks in the same bandwidth, a real-time data acquisition-based experiment has been carried out with hardware in radiated mode to simulate in-orbit conditions in an anechoic chamber.
This paper explains the estimation of interference, test methodology & results and recommends the optimal configuration of the ground receiver for demodulation of the CDMA signal in the presence of interference from multiple narrow-band phase modulated signals. The proposed configuration has been proved successful in a recent GEO spacecraft mission.

Author Biographies

Kosuru Sai Malleswar, U R Rao Satellite Centre, Bengaluru, Karnataka

Scientist/Engineer, Communication Systems Group

Himani BS, U R Rao Satellite Centre, Bengaluru, Karnataka

Scientist/Engineer, Communication Systems Group

Khan Afzaal, U R Rao Satellite Centre, Bengaluru, Karnataka

Scientist/Engineer, Communication Systems Group

Sirshendu Das, U R Rao Satellite Centre, Bengaluru, Karnataka

Scientist/Engineer, Communication Systems Group

Suman R. Valke, U R Rao Satellite Centre, Bengaluru, Karnataka

Scientist/Engineer, Communication Systems Group

Senthil Kumar V., U R Rao Satellite Centre, Bengaluru, Karnataka

Scientist/Engineer, Communication Systems Group

Ramalakshmi N., U R Rao Satellite Centre, Bengaluru, Karnataka

Scientist/Engineer, Communication Systems Group

Published

2023-10-13

Issue

Section

Articles