A Variable Step-size CLMS Algorithm and Its Analysis

• Published in: Radioengineering Vol. 29; no. 1; pp. 182 - 188
• Main Authors: Fan, X., Tan, Z., Song, P., Chen, L.
• Format: Journal Article
• Language: English
• Published: Spolecnost pro radioelektronicke inzenyrstvi 01.04.2020
• Subjects: convex combination; hyperbolic tangent function; least mean square (lms) filters; variable step-size
• ISSN: 1210-2512; 1805-9600
• DOI: 10.13164/re.2020.0182

In this paper, a hyperbolic tangent variable step-size convex combination of the least mean square (HTVSCLMS) algorithm is proposed and analyzed. This work avoids the compromise between the convergence speed and the steady-state error for two filters in convex combination of the least mean square (CLMS) algorithm. In the proposed algorithm, the big step-size filter is replaced by a filter whose iteration step-size is a modified function based on hyperbolic tangent function. Thus it constructs hyperbolic tangent nonlinear relationship between step-size and error. At the same time, the small step-size filter remains unchanged but fixed. So, it conquers the slow convergence speed and the weak anti-interference ability of fixed step-size CLMS. Simulation results show that HTVSCLMS algorithm, compared with CLMS algorithm and variable step-size CLMS (VSCLMS) algorithm, not only has superior capability of tracking in the presence of noise and in a stable and even non-stable environment, but also can maintain a better convergence.