Modeling of Memory-based HPA with AM/AM and AM/PM Characteristics using Saleh Model

This document provides a comprehensive explanation of memory-based High Power Amplifier (HPA) modeling techniques. The methodology encompasses AM/AM (Amplitude-to-Amplitude) and AM/PM (Amplitude-to-Phase) characteristic curves, implemented through the classical Saleh model. Memory-based HPA modeling serves as an effective approach for characterizing high-power amplifier behavior in optical communication systems, enabling engineers to better understand and optimize system performance. The implementation typically involves mathematical representation of nonlinear distortion using Saleh's equations: AM/AM distortion A(r) = (α_a·r)/(1+β_a·r²) and AM/PM distortion Φ(r) = (α_φ·r²)/(1+β_φ·r²), where r represents the input signal amplitude and α, β are model parameters. In subsequent sections, we will systematically demonstrate the memory-based HPA modeling methodology, including how to utilize AM/AM and AM/PM characteristic curves to describe amplifier behavior. We will detail the classical Saleh model implementation, covering parameter extraction techniques and code implementation strategies for integrating the model into memory-based HPA simulations. The implementation typically involves creating lookup tables or real-time computation modules for efficient system simulation. Practical code examples may include MATLAB functions for calculating Saleh model outputs and compensating for nonlinear distortions. Upon completing this document, readers will gain thorough understanding of memory-based HPA modeling approaches and their application in designing and optimizing optical communication systems, including practical implementation considerations for digital pre-distortion algorithms and system performance analysis.