Techniques for deriving a channel impulse response estimate (CIRE) having
improved quality are described. A first CIRE with multiple channel taps
is obtained based on (1) an initial CIRE derived from a received pilot or
(2) a filtered CIRE derived from the initial CIRE. In one aspect, the
channel taps in the first CIRE are scaled with multiple scaling factors
to obtain a second CIRE. For point-wise LMMSE scaling, the energy of each
channel tap is estimated. The noise energy for the channel taps is also
estimated, e.g., based on energies of channel taps on one or both edges
of the first CIRE. Each channel tap is scaled based on a scaling factor
determined by the energy of that channel tap and the noise energy. Each
channel tap with energy below a threshold may be set to zero. In another
aspect, the second CIRE is obtained by zeroing out selected ones of the
channel taps in the first CIRE.