PhD

Abstract: An omni-directional antenna for telemetry, tracking and command (TT&C) com- munications is required for spin-stabilized geostationary satellites whether in the launching phase or once in orbit. The need for a despun platform can even be reduced by implementing a conformal microstrip antenna array °ush mounted on the cylindrical surface of the satellite for that purpose. The analysis and design of this kind of antennas is quite complicated and a powerful simulation software proves indispensable to achieve this goal.

Abstract: Performance and flexibility of mobile radio systems essentially depend on the choice of the multiple access scheme. The novel Multicarrier Code Division Multiple Access (MC-CDMA) scheme which is the topic of this thesis is a promising alternative to conventional FDMA, TDMA, and CDMA schemes. With MC-CDMA, each data modulated chip of the user specific spreading code is mapped onto a separate subcarrier, so that the chips of the spreading code and, hence, the data symbol is transmitted in parallel on multiple subcarriers which introduces frequency diversity.

Abstract: In an attempt to keep flexibility of a programmable solution and the efficiency of dedicated solution, Field Programmable Gate Arrays (FPGAs) are beginning to emerge as a viable option. In this view, FPGAs are an attractive option for implementing digital communication systems for reasons of performance, power consumption, and reconfigurability. This work examines techniques for developing, modeling and generating FPGA implementation of QPSK modem. Amongst the more complex and demanding tasks performed in high data rate wireless communication system is synchronization.