MATLAB Implementation of Digital Communication Systems: BPSK, QPSK, and 16QAM

In this article, we implement three fundamental digital communication modulation techniques using MATLAB: Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), and 16-Quadrature Amplitude Modulation (16QAM). Our implementation details the core principles of each modulation scheme and demonstrates the complete simulation workflow using MATLAB. The code includes constellation diagram generation using scatterplot function, symbol mapping algorithms with conditional statements or lookup tables, and AWGN channel simulation using randn function for noise addition. We thoroughly analyze simulation results including bit error rate (BER) performance calculated through comparison loops, spectral efficiency measurements using FFT-based power spectral density computations, and robustness evaluation under varying SNR conditions. Each technique's comparative advantages and limitations are discussed with supporting MATLAB visualization outputs. Furthermore, we explore practical applications of these modulation schemes in modern communication systems and review recent advancements in related fields. The article aims to provide readers with deeper understanding of digital communication fundamentals while offering valuable reference material for researchers through commented MATLAB code examples featuring key functions like pskmod, qammod, and berawgn for performance benchmarking.