Digital modulation techniques are basic building blocks of the physical or radio interface of all digital communication systems. In a digital communication system with a wireless link, the channel effects can heavily degrade the system performance since the wireless link is time-varying and may experience multipath fading and interference. This book gives the idea about three major types of modulation techniques, namely QPSK, MSK, and 16-QAM, applied to additive white Gaussian noise (AWGN) channel and Rayleigh fading channel and tries to find out the performance of these modulation schemes using forth-generation numerical computing environment, MATLAB. The book is targeted to the academic students as well as researchers and would help them to understand the performance degradation of digitally modulated signals due to Rayleigh fading channel with respect to that of an AWGN channel.