A robust variable step size algorithm for LMS adaptive filters

This work presents a modified version of the variable step size Kwong and Johnston's algorithm (VSS) for LMS adaptive filtering. The new proposal, called Robust Variable Step Size (RVSS), presents less sensitivity to the power of the measurement noise with only a very small increase in the computational complexity. A theoretical analysis demonstrates the main properties of the new algorithm. For white Gaussian input signals the RVSS presents the same performance than the original VSS in a noise free environment. Simulation results are provided, showing the better performance of the new algorithm. The RVSS should find application, for example, in telephony applications when double talking interferences are significant.