Implementation of a block adaptive filter working in the frequency domain combined with a robust adaptation control

Adaptive filters for hands-free telephone systems need an adaptation control which locks or slows down the adaptation process during double talk periods. In this contribution a block adaptive filter algorithm working in the frequency domain which combines a significant reduced numerical complexity with the same tacking abilities as the NLMS algorithm is presented. Moreover we control the stepfactor of the adaptive filter with an adaptation control based on a correlation criterion and several signal power estimators. The adaptation control is robust against double talk.