QPSK Modulation and Demodulation Simulink Model

QPSK modulation and demodulation model using Simulink simulation. QPSK (Quadrature Phase Shift Keying) is a digital modulation technique that converts digital signals into analog signals for transmission. In this model, we utilize Simulink to simulate and validate the performance of QPSK modulation and demodulation. The implementation involves key components including a random bit generator, QPSK modulator with constellation mapping, AWGN channel simulation, and QPSK demodulator with maximum likelihood detection algorithm. Through modulation and demodulation processes, we achieve efficient data transmission while maintaining low bit error rates. During simulation, we can observe waveform characteristics, spectral properties after modulation/demodulation, and BER (Bit Error Rate) performance variations. This simulation model incorporates critical functional blocks such as pulse shaping filters (e.g., raised cosine filter), carrier synchronization modules, and error rate calculation units. The simulation enables comprehensive analysis of QPSK system performance under different SNR conditions, providing insights into practical implementation considerations like phase recovery techniques and symbol timing synchronization. Through this simulation model, we can better understand and analyze the principles and performance characteristics of QPSK modulation and demodulation systems.