16QAM System Modulation and Demodulation Simulation

This implementation provides a detailed simulation analysis of 16QAM system modulation and demodulation processes. The simulation code first generates a constellation diagram using MATLAB's scatterplot function or custom mapping algorithms to visualize the distribution of 16 signal points in the complex plane, representing 4 bits per symbol. For waveform analysis, the code implements digital modulation using IQ modulation techniques, where binary data is mapped to 16 discrete amplitude-phase combinations. The demodulation process employs matched filtering and maximum likelihood detection algorithms to recover the original signal, with waveform comparisons showing signal transformation during transmission. Power spectral density calculation is performed using FFT-based periodogram methods or Welch's algorithm to analyze the frequency characteristics of the modulated signal. The eye diagram generation utilizes oversampling and synchronization techniques to visualize signal quality and timing recovery performance at the receiver side. Finally, the simulation includes BER curve generation by comparing transmitted and received bits across different SNR values, typically implemented using Monte Carlo simulation methods with additive white Gaussian noise (AWGN) channel modeling to evaluate system performance and reliability under various channel conditions.