Generalized sidelobe canceller based combined acoustic feedback- and noise cancellation

We propose a combination of the well-known generalized sidelobe canceller (GSC) or Griffiths–Jim beamformer, and the so-called PEM-AFROW algorithm for joint estimation under closed loop conditions of a room impulse response and a desired speech signal model, resulting in a system for multimicrophone combined acoustic feedback and noise cancellation. For specific applications (e.g. public address systems), the computational complexity may be reduced dramatically compared to state-of-the-art proactive acoustic feedback cancellers, while feedback cancellation performance is only marginally degraded.