An apparatus, a carrier medium storing instructions to implement a method,
and a method for controlling the gain of a radio receiver for receiving
packets of information in a wireless network. The receiver is connected
to an antenna subsystem and has receive signal path including a plurality
of sections including a first section coupled to the antenna subsystem
and a next section. Each section has an adjustable gain and is able to
provide a measure of the signal strength at its output. The method
includes waiting for a start of packet indication, providing a measure of
the signal strength at the output of the first section and the next
section, and adjusting the gains of the first and the next sections using
the provided measured signal strengths. In one embodiment, the receive
signal path includes a filter, the provided measure for the first section
is before the filter, and the provided measure for the second section is
after the filter. The gain adjusting sets first section's gain according
to the measured signal strength at the output of the first section and
sets the next section's gain according to the provided measure of signal
strength at the output of the next section relative to the provided
measure of signal strength at the output of the first section. In one
embodiment, the gain adjusting o is carried out in sequential AGC stages,
one stage setting the gain of one or more sections.