Developing fast and robust methods for identifying multiple FIR channe
ls driven by an unknown common source is important for wireless commun
ications, speech reverberation cancellation, and other applications. I
n this correspondence, we present a new method that exploits a minimum
noise subspace (MNS). The MNS is computed from a set of channel outpu
t pairs that form a ''tree.'' The ''tree'' exploits, with minimum redu
ndancy, the diversity among all channels. The MNS method is much more
efficient in computation than a standard subspace method. The noise ro
bustness of the MNS method is illustrated by simulation.