Simulation of 4FSK Modulation and Demodulation Using MATLAB

This project implements a comprehensive simulation of 4FSK (4-level Frequency Shift Keying) modulation and demodulation using MATLAB. The simulation employs raised-cosine filters for both transmit and receive filtering operations to achieve optimal spectral characteristics. During the simulation process, we first configure modulation parameters including carrier frequency and modulation index using MATLAB's communication toolbox functions. The transmission chain involves generating baseband symbols, mapping them to four distinct frequency carriers using digital modulation techniques, and applying raised-cosine filtering with specified roll-off factors to limit out-of-band power emission. On the receiver side, the captured signal undergoes matched filtering using an identical raised-cosine filter to minimize intersymbol interference, followed by coherent demodulation employing frequency discrimination or phase-locked loop techniques. The demodulation process includes symbol timing recovery, decision-making circuitry, and error rate calculation modules. Performance evaluation metrics such as bit error rate (BER) versus signal-to-noise ratio (SNR) are analyzed through Monte Carlo simulations, enabling system optimization through parameter adjustment and algorithm refinement.