μ-Law Companding Implementation for OFDM Peak-to-Average Power Ratio Reduction

This MATLAB program implements μ-law companding technique to suppress Peak-to-Average Ratio (PAR) in OFDM signals. The code processes input signals through μ-law compression and expansion operations, effectively reducing PAR while maintaining signal integrity. The implementation follows a two-stage companding process: first applying μ-law compression to reduce signal peaks, followed by expansion to restore the average power level. The algorithm utilizes MATLAB's signal processing functions to implement the μ-law characteristic equation: y = (log(1+μ|x|)/log(1+μ)) * sign(x), where μ is the compression parameter typically set between 100-255 for optimal performance. This program has broad applications in communication systems requiring PAR reduction, particularly in OFDM-based technologies like 4G/5G and Wi-Fi. The code structure includes modules for signal generation, μ-law transformation, PAR calculation, and performance visualization. Key functions handle signal normalization, companding parameter optimization, and error vector magnitude (EVM) analysis to ensure transmission quality. By reducing PAR, the implementation minimizes power fluctuations during signal transmission, enhancing system reliability and power amplifier efficiency. The program serves as both a practical tool for communication engineers and an educational resource for understanding non-linear signal processing techniques in wireless communications. The complete MATLAB implementation includes configurable parameters for different modulation schemes, adjustable compression factors, and performance metrics comparison between original and processed signals, making it suitable for both research and practical system optimization.