الفهرس 
صفحة العنوانOnly 14 pages are availabe for public view
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Abstract
The next generation of wireless communication systems requires higher data transmission rates in order to meet the higher demand of quality services, digital modulation schemes provide more information carrying capacity, better quality communications, and data. This research presents the design and implementation of the Quadrature phase shift keying (QPSK) demodulator using digital signal processing techniques. The QPSK demodulator is designed and implemented using two different approaches. In the first approach, digital filters are used for implementing the demodulator. In the second approach, the DFT is used for implementing the demodulator. The first approach is implemented using digital low-pass filters, Costas loop, and numerically controlled oscillator (NCO). In the second approach, the DFT is used in development of the QPSK demodulator by computing the spectrum of the coming modulated signal and finding the maximum peak of the spectrum as it is used to determine the carrier frequency and its phase. The data bits are then determined from the phase of the carrier. Both approaches are implemented using python software and raspberry pi processor for to be used as embedded system and also as experimentation system for high school students. Both design methods are tested and verified through simulation experiments.
The study also showed the effectiveness of the study unit that was applied to the research sample of the students of the industrial high school system three years specialized electronics at the martyr Haitham Sami Hamad School of Art Girls in The Lake governorate that there is a difference between the average grades of the experimental group in the tribal records The dimension of the cognitive test is at the level of 0.01. There is also a difference between the average score of the experimental group in the tribal and remote observation card records at the indicative level of 0.01.