Development of software for signal processing unit of satellite communication ground system

The satellite communication system is mainly composed of a spacecraft and ground segment, where the modem is the primary equipment of the ground station. Regulations and physical constraints require the effective use of the designated spectrum and available energy resources, while making spectral efficiency and energy efficiency to play the key roles in the design. Also, the ever growing demand for high rate data transmission necessitates the exploitation of highly efficient modulation and coding techniques. In this regard, satellite ground station modem becomes one of the most important parts of the system which shall be designed to meet these requirements. Amplitude phase shift keying (APSK) is the emerging modulation scheme adopted in satellite communications because of its high spectral efficiency and robustness. The primary objective of the thesis is to design a satellite ground station modem employing spectrally and energy efficient modulation scheme. In this study, a novel digital modulation scheme so called as quadrature-carrier amplitude phase shift keying (QC-APSK) has been proposed. QC-APSK has improved spectral efficiency against APSK by one third via doubling the transmission rate. Also in this study, extreme learning machine (ELM) based artificial neural soft demapping algorithm has been proposed for demodulation of APSK signals. Simulation results showed that ELM based demapper has reasonable error performance when compared with the optimal max-log-MAP based demapper.