Kernel-Based Digital Predistortion: An Approach with the EX-QKRLS Algorithm

This paper investigates the effectiveness of kernel-based adaptive filtering for digital predistortion in power amplifiers. Specifically, the EX-QKRLS algorithm, which incorporates concepts from the Kalman filter, is employed to model and compensate for the nonlinearities introduced during signal amplification, without requiring memory polynomials or lookup tables. This method reduces overall signal distortion and improves transmission fidelity robustly and efficiently. Unlike conventional approaches, the proposed technique offers high adaptability, enabling rapid adaptation to changing system conditions, including temperature fluctuations and component aging.