Digital Communication Laboratory

The laboratory experiments consist of circuit level implementation of various modulation techniques and as well as numerical simulations using MATLAB. In circuit level implementation, students are guided through an immersive exploration of modulation and demodulation techniques, where they commence with the fundamentals of Amplitude Modulation (AM). Here, the manipulation of carrier and modulating signals unveils the encoding of information through nuanced variations in amplitude. Venturing into Double-Sideband Suppressed Carrier (DSB-SC) modulation, participants delve into the strategic utilization of bandwidth in communication systems, gaining hands-on insights into efficient signal transmission. The laboratory experience extends further to Frequency Modulation (FM), unraveling the underlying principles of encoding data through variations in signal frequency. Pulse Amplitude Modulation (PAM) experiments provide students with an opportunity to intricately dissect the discrete nature of signal modulation, fostering a nuanced understanding of information representation. Additionally, experiments in Pulse Width Modulation (PWM) and Pulse Position Modulation (PPM) shed light on the effective encoding of information through deliberate variations in pulse width and position.

Simultaneously, within Simulation Lab powered by MATLAB, students engage in sophisticated Monte Carlo simulations. They systematically quantify the Average Bit Error Rate (BER) for binary on-off signals, Phase Shift Keying (PSK), and Quadrature Amplitude Modulation (QAM) signals. MATLAB simulations further guide students through the intricate analysis of eye diagrams, providing insights into signal quality, and explore the application of raised cosine pulse shaping in QAM for optimized communication. The integration of Simulink enhances this experience, facilitating a practical understanding of digital communication systems.

This dynamic synthesis of theoretical comprehension and hands-on experimentation across digital domains creates a holistic learning environment. As a result, students not only acquire technical proficiency but also develop a profound appreciation for the interconnected nature of theory and application in the field of electronic engineering.

Fig: DSB-SC signal as seen in DSO

Fig: Eye diagram

Fig: MATLAB Simulink model of raised cosine QPSK