QPSK Modulation MATLAB Program with Baseband Shaping Filter

This project involves developing a MATLAB program for QPSK (Quadrature Phase Shift Keying) modulation incorporating a baseband shaping filter (implemented using a raised cosine filter). QPSK modulation is a widely-used digital modulation technique that enables efficient data transmission within limited bandwidth channels, making it extensively applied in communication systems. The program implementation includes generating QPSK symbols through binary-to-phase mapping, where two bits are encoded into one of four possible phase states (0°, 90°, 180°, 270°). The baseband signal shaping employs a raised cosine filter to reduce intersymbol interference (ISI) by controlling the pulse shape in the time domain. Key MATLAB functions utilized in this implementation include qammod for modulation, rcosdesign for filter creation, and conv for signal filtering operations. Through developing this program, users can gain deeper understanding of QPSK modulation principles, practical implementation techniques, and pulse shaping fundamentals, providing a solid foundation for subsequent communication system design projects.