Fig. 5(a) shows the convergence curves of RLS algorithm, LMS algorithm and the proposed algorithm. In Fig. 5(a), the green solid line is the convergence curve of RLS algorithm, the green dash line is the convergence curve of RLS algorithm with conventional polynomials model [14], the black solid line is the convergence curve of LMS algorithm (δ = 0.05), the black dash line is the convergence curve of LMS algorithm (δ = 0.005), the blue solid line is the convergence curve of the proposed algorithm (1/n), and the blue dash line is the convergence curve of the proposed algorithm (δ(n)).