M.Sc.

Abstract:This work is to design and simulate a switched mode power supply (SMPS) with the required pulsating circuits, to be used in pumping a TEA CO2 laser. The main parts of the switched mode power supply included: input rectifier, input smoothing filter, push-pull converter (chopping circuit), high voltage power transformer, output rectifier, and output smoothing filter. The control circuit for controlling the chopper circuit was the PWM scheme control circuit and the main switching device in the power converter circuit was the bipolar power transistor with high voltage rating.

Abstract:Orthogonal frequency division multiplexing (OFDM) is a promising technique for high data rate wireless communications because it can combat intersymbol interference (ISI) caused by the dispersive fading channel. This is achieved by inserting a guard interval, whose length is at least equal to the maximum channel delay, which reduces the transmission efficiency. Applying multiple-input multiple-output (MIMO) scheme, by adopting multiple transmitting and receiving antennas, can enhance the transmission efficiency and link reliability.

Abstract:The introduction of global system for mobile communication (GSM) air interface has undoubtedly created a new area in telecommunications. In view of its extensive use in real world applications, it is highly desirable to further investigate the performance of the GSM system under different operating conditions and environments. Furthermore, there is increasing interest in using high-level modulation to provide enhanced data rate for GSM evolution (EDGE). This thesis investigates the performance of both GSM and GSM/EDGE systems operating in Raleigh fading channel.