A modified recursive non-quadratic algorithm for adaptive channel equalization

This paper proposes a solution to reduce the inter symbol interferences (ISI) in multipath channels with frequency selective fading. The proposed solution is based on a Modified Recursive Non-Quadratic (MRNQ) adaptive algorithm combined with a Decision Feed-forward Equalizer (DFE) structure, referred to as MRNQ-DFE. First, we studied the behavior of the proposed approach by evaluating the impact of some key factors of the convergence rate, relying on the mean squared error (MSE) criterion. Then, we conducted a comprehensive set of experiments to evaluate the performance of the proposed MRNQ-DFE equalizer compared to other robust adaptive equalizers, such as NLMS-DFE and APA-DFE. These experiments rely on a variety of objective criteria, including the constellation diagram, the eye diagram, the Nyquist criterion, and the MSE criterion. The obtained results show the effectiveness of the proposed equalizer to achieve the desired goal with a superior convergence speed compared to the other strong adaptive equalizers, making it an effective solution for multipath channels in digital communication systems.