Design and FPGA Implementation of Satellite Telemetry Transmitter Employing PCM/PSK/PM Sub-Carrier Modulation Using DDS

In Satellite communication measurement and control system, the most predominant radio telemetry and remote-control modulation system is PCM/PSK/PM. Satellites utilizes PCM/PSK/PM sub-carrier modulation to communicate with Ground station to transmit Telemetry (health) data of satellite. Major space agencies like NASA, ESA & ISRO have employed subcarriers for both tele-command and telemetry data transmissions. Use of sub-carriers allows separating different types of data as well as ensuring no overlap between the modulated data's frequency spectra and the RF carrier. This paper presents the design and FPGA (Field Programmable Gate Array) implementation of Satellite Transmitter employing PCM (Pulse Code Modulation), PSK (Phase Shift Keying), and PM (Phase Modulation) in a subcarrier modulation scheme. The transmitter leverages Direct Digital Synthesizer (DDS) as a key component to achieve precise signal generation. The integration of PCM, PSK, and PM in subcarrier modulation offers advantages in terms of spectral efficiency and signal quality. Algorithm using DDS ip is simulated in Vivado on ZynQ Ultrascale-ZCU111 FPGA board. The FPGA implementation enhances the flexibility and adaptability of the system, making it suitable for a wide range of satellite communication applications. The proposed transmitter architecture is thoroughly analyzed, and its performance is evaluated through simulations and practical experiments, demonstrating its feasibility and effectiveness in satellite communication systems.