To reduce power consumption, receiver circuit blocks within a wireless
device are biased with less current whenever possible while still
achieving the desired performance. The receiver circuit blocks may
include a voltage controlled oscillator (VCO) that generates an
oscillator signal used for frequency downconversion of a received signal
from the forward link, a low noise amplifier (LNA) that amplifies the
received signal, and a mixer that frequency downconverts the received
signal. The VCO may be biased with less current if phase noise
performance is less stringent, e.g., when (1) the wireless device is not
transmitting on the reverse link, (2) a large amplitude jammer is not
detected, and/or (3) the received signal level is sufficiently high. The
bias currents of other receiver circuit blocks may also be adjusted based
on transmitter activity, detected jammer, and/or received signal level.