In this paper, we propose a so called GSC-ATF approach, which is an extended generalized sidelobe canceller (GSC) suitable for arbitrary transfer functions (TFs) relating the signal source and each sensor. The difference between GSC-ATF and conventional beamforming methods is that the latter one uses pure delay channel model. Consequently, the signal cancellation problem is alleviated while it is serious in the conventional beamforming in the presence of reverberant and multipath effects. The implementations of GSC-ATF in time and frequency domain are discussed. Among them, the frequency domain implementation has a lower computation load in the case of large filter length as well as faster convergence speed.