An error path delay compensated delayless subband adaptive filter architecture

The delayless subband adaptive filter has no transmission delay. Its closed-loop configuration converges close to the minimum residual error using feedback from the fullband error signal, but its stability and convergence rate are limited by the error path delay. This paper systematically analyzes the subband/fullband weight transformation and the subband weight update process, investigates the adverse influences of the error path delay, and then introduces a closed-loop block update algorithm with error path delay compensation. Simulation results for an acoustic echo cancellation application confirm that this modified algorithm rapidly converges to small residual error with low computational complexity.