MATLAB Implementation of Digital Modulation and Demodulation Programs

This MATLAB implementation provides complete digital modulation and demodulation programs for BPSK, QPSK, 8QAM, 16QAM, and 32QAM modulation schemes. The code architecture allows these programs to function as independent modules that can be seamlessly integrated into any channel environment. The demodulation process implements two distinct approaches: maximum likelihood detection for optimal performance and lower-complexity threshold-based detection for resource-constrained applications. Each modulation scheme supports detailed parameter configuration through structured input arguments, including symbol mapping, carrier frequency, sampling rate, and filter coefficients, enabling adaptation to diverse communication requirements. The implementation incorporates automatic signal quality detection algorithms that monitor metrics like SNR, BER, and constellation distortion. This facilitates real-time error correction mechanisms and comprehensive bit error rate analysis through statistical processing functions. For performance optimization, the code includes comparative analysis tools that allow experimental evaluation of different modulation schemes under identical channel conditions. Key functions include: modulation mapping using lookup tables, pulse shaping with raised-cosine filters, coherent detection with phase recovery loops, and decision metric calculators. The program offers extensive functionality and flexible configuration options through modular class structures and parameterized function calls, making it suitable for complex communication system simulations and practical implementation scenarios.