MATLAB Implementation of FSK Modulation with Detailed Code Examples

This implementation provides a detailed MATLAB-based solution for Frequency-Shift Keying (FSK) modulation, a digital modulation technique that encodes information through frequency variations. The code follows a systematic approach with clear documentation and modular structure. The implementation begins by defining key parameters including carrier frequency and frequency deviation values. Using MATLAB's signal processing capabilities, the code generates two distinct waveforms representing binary states (0 and 1) through frequency modulation. The modulation process involves creating time-domain signals using sinusoidal functions with different frequencies, then combining them based on the input binary sequence. A crucial aspect of this implementation is the noise simulation module, which adds adjustable Gaussian white noise to the transmitted signal using MATLAB's awgn function or custom noise generation algorithms. This feature allows testing the system's robustness under various channel conditions. The demodulation section implements a coherent detection scheme using bandpass filtering techniques. The code employs MATLAB's filter design functions (like butter or cheby1) to create filters centered at the two frequency states. The demodulation algorithm compares the filtered signal amplitudes using envelope detection or energy calculation methods, followed by threshold-based decision making to recover the original binary data. The visualization component utilizes MATLAB's plotting functions (plot, subplot, stem) to display waveforms, spectral characteristics, and bit error rate performance. The code includes comprehensive comments explaining each processing stage, from signal generation to performance analysis. This implementation demonstrates professional coding practices with parameterized variables, modular functions, and error handling mechanisms. It serves as an excellent educational resource while being practically adaptable for real-world communication system prototyping.