Abstract
Digital communication has proven to be the most efficient method of data transmission especially where long distances are involved. This led to the invention of more sophisticated methods of communication ranging from mobile handset communication to more advanced satellite communication. The speeds of passing information have been improving over the years and real time video communication has been made possible with digital devices. Various methods of digital data transmission are employed based on the information to be transmitted. This paper focuses on carrier recovery in digital communication systems, especially those based on Quadrature Phase Shift Keying (QPSK) modulation and demodulation scheme. The design being implemented is that of coherent demodulation for QPSK scheme using SIMULINK design tool. Performance of QPSK is also investigated to make a comparison and the suitability of the scheme to use in digital data transmission applications.