Acoustic echo cancellation in mobile radio by adaptive Legendre filtering

Discrete-time analysis and modeling of resonant and reverberant systems has many applications in acoustics. Although autoregressive moving average modeling, which yields a pole-zero filter has a lot of modeling power, Prony's and Steiglitz-McBride estimation methods can result in an unstable model, even for stable target systems. On the other hand, finite impulse response modeling can require a large filter order in order to accurately model the target system. This paper discusses the application of an adaptive Legendre network realization on the acoustic echo cancellation in mobile radio. Such kind of system modeling has an infinite impulse response, but with all the poles inside the unit circle.