Design and Implementation of Earth station Transceiver employing subcarrier composite PCM/PSK/PM Modulation & Demodulation using MATLAB

This paper focuses on the design and implementation of an Earth station transceiver system that employs an innovative approach combining subcarrier composite Pulse Code Modulation (PCM), Phase Shift Keying (PSK), and Phase Modulation (PM) for modulation and demodulation processes. The study leverages MATLAB as the primary platform for simulation and analysis. The proposed system aims to enhance communication efficiency and reliability in satellite-based transmissions by integrating advanced modulation techniques. The study involves the development of comprehensive models for PCM, PSK, and PM modulation schemes, followed by their integration into a subcarrier composite framework. The MATLAB simulations assess the performance of the designed transceiver system under various conditions, such as channel impairments and noise, providing insights into its robustness and effectiveness. The satellite modulation scheme employs conversion of PCM bit stream data to NRZ-L encoding and applying BPSK modulation on NRZ-L data and later BPSK signal is Phase modulated to obtain PCM/PSK/PM sub carrier modulation. The demodulation scheme carried out on composite PCM/PSK/PM modulated signal. First it is PM demodulated and passed through FIR low pass filter to eliminate high frequency components to obtain PSK/PCM signal. The PSK/PCM signal then undergoes demodulation to get PCM (NRZ-L) signal and then PCM signal is then decoded to get original digital data transmitted. A proof-of-concept experiment has been realized on MATLAB. The simulation result validates the proposed architecture.