Implementation of 16QAM Modulation and Demodulation System

In this implementation, we developed a 16QAM (16-Quadrature Amplitude Modulation) modulation and demodulation system without relying on any built-in MATLAB or communication toolbox commands. The system follows standard digital communication protocols by implementing the complete signal processing chain from baseband signal generation to constellation mapping/demapping. The implementation involves creating custom algorithms for: - Symbol mapping using 4-bit Gray coding to minimize bit error rate - I/Q signal generation with 16 discrete amplitude-phase combinations - Pulse shaping using raised-cosine filters for bandwidth efficiency - Coherent demodulation with carrier recovery and timing synchronization - Decision regions implementation for constellation point detection This approach allows for better understanding of signal transmission and reception mechanisms, while providing flexibility to optimize system performance parameters such as bit error rate, spectral efficiency, and implementation complexity. The custom implementation also enables educational analysis of signal impairments and error correction techniques.