QPSK Modulation and Demodulation MATLAB Program

This article presents my MATLAB implementation of Quadrature Phase Shift Keying (QPSK) modulation and demodulation. The program efficiently converts input binary data streams into QPSK-modulated signals and reconstructs original bit sequences from received QPSK signals. Key implementation aspects include: - Utilizing MATLAB's built-in functions for digital signal processing operations - Implementing QPSK modulation through quadrant mapping (00→45°, 01→135°, 10→225°, 11→315°) - Employing coherent detection with phase synchronization for demodulation - Incorporating error-checking mechanisms to ensure transmission reliability The code structure features modular design with separate functions for constellation mapping, pulse shaping, and decision thresholds. Performance validation includes BER calculations under varying SNR conditions using MATLAB's communication toolbox functions. For technical inquiries or implementation assistance, please feel free to contact me for detailed code discussions and optimization suggestions.