QPSK Modulation and Demodulation Simulation Using SIMULINK

The QPSK SIMULINK modulation and demodulation simulation is guaranteed to execute successfully. In this simulation, QPSK (Quadrature Phase Shift Keying) modulation technique is employed for digital signal transmission. QPSK is a widely-used modulation scheme that maps two bits per symbol, doubling the data rate compared to BPSK while maintaining the same bandwidth. The simulation utilizes SIMULINK's visual programming environment to model the complete communication chain, including symbol mapping, pulse shaping, AWGN channel, and coherent detection. Key components implemented include the QPSK modulator using phase shifts of 0°, 90°, 180°, and 270° to represent symbol pairs (00, 01, 11, 10), and the demodulator employing carrier recovery and decision circuits for symbol detection. The simulation validates QPSK's performance metrics such as bit error rate (BER) under varying SNR conditions, ensuring reliability and stability for practical applications. Parameter tuning options allow testing different filter configurations (e.g., raised-cosine) and synchronization methods, providing insights into real-world implementation challenges.