A wireless receiver detects signals received at two or more antennas, with
each antenna coupled to an input receive chain. A switch is employed to
couple selected input receive chains to one or more corresponding output
receive chains during listening, coarse-detection, and fine-adjustment
modes. At least one channel selection filter (CSF) is employed in each
output receive chain, and the receiver employs sub-ranging. During idle
mode, one antenna's input receive chain is connected to two or more CSFs
to detect the packet. When the packet is detected, during a
coarse-adjustment mode, the CSFs are reconfigured to couple each
antenna's input receive chain to a corresponding output receive chain
using low-gain signals. During fine-adjustment mode, the various gains
are adjusted to be either high- or low-gain to maintain signals within
the dynamic range of the corresponding CSFs.