MATLAB Implementation of MSK Modulation and Demodulation

The MSK modulation and demodulation program represents a fundamental digital communication technique, encompassing both conventional MSK modulation/demodulation methods and Gaussian Minimum Shift Keying (GMSK) implementations. MSK modulation is a continuous-phase modulation technique that maintains a constant phase change rate during transmission, providing excellent spectral efficiency and multipath interference resistance through its constant envelope property. In MATLAB implementation, this typically involves generating orthogonal I/Q components using sinusoidal weighting functions and maintaining phase continuity between symbol transitions. GMSK modulation enhances standard MSK by passing the baseband signal through a Gaussian filter prior to modulation, resulting in smoother spectral characteristics and reduced bandwidth consumption. The MATLAB implementation requires careful parameter selection for the Gaussian filter's BT product (bandwidth-time product) to control the trade-off between spectral compactness and intersymbol interference. Key functions in the implementation would include waveform generators for creating continuous-phase frequency pulses, Gaussian filter design using functions like gaussfir or gaussdesign, and coherent detection algorithms employing phase-locked loops for symbol timing recovery. These modulation techniques find extensive applications in wireless communication systems, particularly in GSM, Bluetooth, and satellite communications where spectral efficiency and power efficiency are critical requirements.