A new RLS algorithm based on the variation characteristics of a room impulse response

The paper proposes a new adaptive algorithm (called the ES-RLS algorithm) with double the convergence speed of the conventional RLS algorithm. Makino et al. (1993) showed that the variation of a room impulse response becomes progressively smaller along the series by the same exponential ratio as the impulse response. The ES-RLS algorithm is derived by incorporating these variation characteristics into the conventional RLS algorithm using Kalman filter theory, which gives physical meaning to the RLS algorithm. The ES-RLS algorithm adjusts coefficients with large errors in large steps and coefficients with small errors in small steps. Computer simulations demonstrated that the new adaptive algorithm converged twice as fast as the conventional RLS algorithm